Automated Selectivity

One of the reasons we like to look at paintings is that reality is filtered through someone's brain. Painters select the important elements out of the infinite detail that meets our eyes. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXNaeEBJrZH7OXAnjbLlMD_UWbPZ3lpEj6VF6EHXOL50GNAh4B_r2h1Ui83DMQWVNLJNcjntVL3ZWcGkxvA7APqwqel9ZBk7L7UR-rItMJ3uYMzbQAW7WZyBNppybykaMu5j8doUObztU/s1600/Parker_Night_Call.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXNaeEBJrZH7OXAnjbLlMD_UWbPZ3lpEj6VF6EHXOL50GNAh4B_r2h1Ui83DMQWVNLJNcjntVL3ZWcGkxvA7APqwqel9ZBk7L7UR-rItMJ3uYMzbQAW7WZyBNppybykaMu5j8doUObztU/s320/Parker_Night_Call.jpg" width="242" /></a><br />Here, Al Parker chooses to show us detail in the hands and face. He sinks everything else into a flat tone. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0zhTMMkZcSIJQuZltPiUAq6P0HX3AwUq-nzohDsBWlR6u1t8ZJTQ43XDvT4CHNLUQaJ5XTqCbJDupLJVfAvAjz4BPnuOIySFuG2bAmcV7gTBv5U9d9s6EzGmxitXuzTarlcZVumPOlOM/s1600/Sargent.Street_in_Venice.sm.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="308" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0zhTMMkZcSIJQuZltPiUAq6P0HX3AwUq-nzohDsBWlR6u1t8ZJTQ43XDvT4CHNLUQaJ5XTqCbJDupLJVfAvAjz4BPnuOIySFuG2bAmcV7gTBv5U9d9s6EzGmxitXuzTarlcZVumPOlOM/s400/Sargent.Street_in_Venice.sm.jpg" width="400" /></a><br />John Singer Sargent could have detailed every paving stone and roof tile in this Venice street scene. Instead he softened and simplified the background areas and put the focus on the faces. <br /><br />This selectivity isn’t arbitrary. The detailed areas correspond with the parts of the picture that we want to look at anyway.  As we’ve seen in previous posts, eye tracking studies have demonstrated the cognitive basis of selective attention. Viewers’ eyes consistently go to areas of a picture with the greatest psychological salience: things like faces, hands, and signs. We’re hard-wired for it.<br /><br />What happens if you combine eye tracking data with computer graphics algorithms to automate the process of selective omission? Would the result look “expressive” or “artistic?” <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2YNLCKYr5wMP9KjVu_pdZfnJs-wI7PF1qnOTr4V4dq0Gu5ApatetLm7jdDF8rrgJRy9EYKghTxL5EC3oJSfCr_oGAdxsvkLs4n5YcoZ7ODcyYLxYgs0-5cICn2pfzJQvsx0QonlU-MGk/s1600/Painterly_Abstraction.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2YNLCKYr5wMP9KjVu_pdZfnJs-wI7PF1qnOTr4V4dq0Gu5ApatetLm7jdDF8rrgJRy9EYKghTxL5EC3oJSfCr_oGAdxsvkLs4n5YcoZ7ODcyYLxYgs0-5cICn2pfzJQvsx0QonlU-MGk/s320/Painterly_Abstraction.jpg" width="265" /></a><br />(Click to enlarge) In his doctoral thesis for Rutgers University, Anthony Santella did just that. The photographs on the left include a set of overlapping circles showing where most people spent their time looking in each image. The larger the circle, the longer the concentration on those areas.<br /><br />Santella combined that data with a rendering algorithm which simplified other areas of the image. In the top image, note the flattening of the far figures and the arches above them. In the bottom image of the woman, note how the wrinkles in the drapes and the textures in the sweater are rendered with flat tones. But her eyes, nose and mouth are still detailed. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiib97z3ZmBpEzMSeyTYeMBGEnxdTUsR15MYfopT_Vx4ffhzUT7GFGIXC7y6gp-mrff4KTUerC0UIIDP8_l1s9OQwilsOMnczCVnozKeFx2rvQMrTavOS2HReDw48CckBFeekRoPJmAaHA/s1600/Guitarist_Street.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="282" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiib97z3ZmBpEzMSeyTYeMBGEnxdTUsR15MYfopT_Vx4ffhzUT7GFGIXC7y6gp-mrff4KTUerC0UIIDP8_l1s9OQwilsOMnczCVnozKeFx2rvQMrTavOS2HReDw48CckBFeekRoPJmAaHA/s400/Guitarist_Street.jpg" width="400" /></a><br />The rendering algorithms can be designed to interpret the source photo in terms of line and color. Or the shapes can modulated in size according to the interest factor. Note how the outlying areas of each rendering is simplified.<br /><br />Whichever rendering style one desires, the output image has a sense of psychological relevance, more so than <a href="http://gurneyjourney.blogspot.com/2010/01/automated-painting.html">rendering algorithms based merely on abstract principles</a> such as edge detection. As a result these computer-modified photographs have a sense of something approaching true human artistry.<br /><br />The results of this interaction between eye-tracking data and computer rendering algorithms suggests a heretical thought: What we think of as a rare gift of expressive artistic judgment is really something fairly simple and logical, something you can teach a machine to do.<br /><br />"THE ART OF SEEING: VISUAL PERCEPTION IN<br />DESIGN AND EVALUATION OF<br />NON-PHOTOREALISTIC RENDERING"<br />by Anthony Santella<br /><a href="http://www.research.rutgers.edu/%7Easantell/thesis.pdf">www.research.rutgers.edu/~asantell/thesis.pdf</a><br />Final two sets of images are courtesy this online graduate thesis.  <br /><br />Previous related posts on GurneyJourney: <br /><a href="http://gurneyjourney.blogspot.com/2009/12/abstraction-generator.html">Abstraction Generator</a><br /><a href="http://gurneyjourney.blogspot.com/2010/01/automated-painting.html">Automated Painting</a><br /><a href="http://gurneyjourney.blogspot.com/2007/09/al-parker-at-rockwell.html">Al Parker at the Rockwell</a><br /><a href="http://gurneyjourney.blogspot.com/2009/11/eyes-have-it.html">The Eyes Have It</a><br /><a href="http://gurneyjourney.blogspot.com/2008/01/stroke-module.html">Stroke Module</a><br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-1.html">Eyetracking and Composition, part 1 </a><br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-2.html">Eyetracking and Composition, part 2 </a><br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-3.html">Eyetracking and Composition part 3</a><br />Introduction to eyetracking, <a href="http://gurneyjourney.blogspot.com/2009/02/what-are-you-looking-at.html">link.</a><br />How perception of faces is coded differently, <a href="http://gurneyjourney.blogspot.com/2008/05/never-forget-face.html">link.</a>

Automated Selectivity

One of the reasons we like to look at paintings is that reality is filtered through someone's brain. Painters select the important eleme...

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Blue Light and the Circadian Clock

Researchers at the <a href="rpi:%20http://www.lrc.rpi.edu/resources/news/enews/Apr05/general245.html">Rensselaer Polytechnic Institute</a>'s Lighting Research Center (LRC) in Troy, New York are proving that exposure to blue light is tied to the day/night sleep cycles of our circadian rhythms.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhpCOYaeJnsfttdbpl8p3Me2JX8jTmphAzUSeDh9IzmuA0IHYxXKGKwL7V30dDn1Lx_th6SlWDVanTs86LU5OJUQO0L4s5XVK0qwp1k4Md3bv-OolxZLPvVDTdOAViicjoL3IawvaGaPw/s1600/Levitan.bonfire+copy.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhpCOYaeJnsfttdbpl8p3Me2JX8jTmphAzUSeDh9IzmuA0IHYxXKGKwL7V30dDn1Lx_th6SlWDVanTs86LU5OJUQO0L4s5XVK0qwp1k4Md3bv-OolxZLPvVDTdOAViicjoL3IawvaGaPw/s400/Levitan.bonfire+copy.jpg" width="400" /></a><br />Mariana Figueiro, PhD., who heads the LRC’s light and health program explains:<br /><br /><blockquote>“Within the mechanism that affects the circadian system are two color opponent channels. One of those is the blue vs. yellow (BY) channel, which seems to participate in converting light into neural signals to the part of the brain that generates and regulates circadian rhythms.” </blockquote><br />A person attuned to the changing colors of outdoor light will notice that just after the orange-colored sun sets, the world is bathed in blue light from the twilight sky. So perhaps it’s not surprising that our body rhythms are tuned by this color. <br /><br />In one LRC study, patients with Alzheimer’s disease experienced more hours of sleep per night after being exposed to blue LED lights than they did after being exposed to red lights.<br /><br />“Blue sky is ideal for stimulating the circadian system because it’s the right color and intensity, and it’s ‘on’ at the correct time for the right duration—the entire day,” said LRC director Mark Rea, Ph.D., <br /><br />Presumably, since non-human animals also have the BY channel, they would respond to the same signals.  <br />--------<br /><a href="http://www.sciencedaily.com/videos/2006/0201-waking_up_teens.htm">Science Daily article about waking up teens with colored light</a><br /><a href="rpi:%20http://www.lrc.rpi.edu/resources/news/enews/Apr05/general245.html">RPI Lighting Research Center article</a><br />Painting is called "Bonfire" by <a href="http://en.wikipedia.org/wiki/Isaac_Levitan">Isaac Levitan </a>

Blue Light and the Circadian Clock

Researchers at the Rensselaer Polytechnic Institute 's Lighting Research Center (LRC) in Troy, New York are proving that exposure to blu...

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Gaze Direction

Which way are these eyes looking? Do they seem to be looking right at you, or off to the side?<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv6Z6SRxEzUAEHbggKGzTF_Ov_N14FrNURYiVDK75phADxlSlsEifY-XbVHtidCRcIFpWkJOWEDOhQt1t6GZmp6M8E41_Aj2WaoEk_cY9tIaLgGtSMaW3_CtaBTaIe8nGO06Fz_u_eEMY/s1600/Gaze_Direction_Wollaston.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="152" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv6Z6SRxEzUAEHbggKGzTF_Ov_N14FrNURYiVDK75phADxlSlsEifY-XbVHtidCRcIFpWkJOWEDOhQt1t6GZmp6M8E41_Aj2WaoEk_cY9tIaLgGtSMaW3_CtaBTaIe8nGO06Fz_u_eEMY/s400/Gaze_Direction_Wollaston.JPG" width="400" /></a><br />Our perception of gaze direction is influenced by the position of the iris inside the visible surface of the sclera (the white of the eye), but that’s only part of the story.<br /><br />In 1824 William Henry Wollaston made exact duplicates of an engraved plate of eyes and eyebrows. He then placed them in two different facial contexts. One face is turned one way, and the other points in the opposite direction. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmXjKqx-vqKDLwRf_zMxjPi2ow5HjuOWbWfqQQqPinJwvp3prjPVRZioZDmYWhjnyWO8aH6JMtinln0FOCsKUu-t3hsSIA9AthZfAfLLIadBWkb5woiQ22RSON6MQsh8swrdIgbAEtpZc/s1600/William_Wollaston_Gaze_Direction.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmXjKqx-vqKDLwRf_zMxjPi2ow5HjuOWbWfqQQqPinJwvp3prjPVRZioZDmYWhjnyWO8aH6JMtinln0FOCsKUu-t3hsSIA9AthZfAfLLIadBWkb5woiQ22RSON6MQsh8swrdIgbAEtpZc/s400/William_Wollaston_Gaze_Direction.JPG" width="400" /></a><br />Surprisingly the exact same set of eyes appears to be looking in different directions solely because of the surrounding facial cues. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzMY8gg0wZIYq_W61cUQQpdD4Vq4uHmyt-lWloxCgkVrHbIqkGSzjf9JZSc7mgMZAco5DeZzc1SVAgHqyhyphenhyphenJAsZFUtIUin7gpnAerGyhg_upRUwZDtForNnEFxtFhad_liNqLcUXgGh7A/s1600/Wollaston_Gaze_Direction.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="193" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzMY8gg0wZIYq_W61cUQQpdD4Vq4uHmyt-lWloxCgkVrHbIqkGSzjf9JZSc7mgMZAco5DeZzc1SVAgHqyhyphenhyphenJAsZFUtIUin7gpnAerGyhg_upRUwZDtForNnEFxtFhad_liNqLcUXgGh7A/s400/Wollaston_Gaze_Direction.JPG" width="400" /></a><br />Even if you take a matched pair of eyes and eyebrows and just shift the nose beneath them from one side to the other, you can shift the apparent direction of gaze.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3tmTV2x4MP_fwh8h_TZ0k31WCIOlcn7uVDQQkf_taBOqoNH4QAO-_bJoXDlpa3Eud1neYX0vPrWfhiBf_FjcbmNaHioHZOO1R-OUAGrYyZcU9h5N8rvcmPyQmcsyIEN0p6PyZgTOd6ww/s1600/Donald.Duck.copyrightDisney.gif" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3tmTV2x4MP_fwh8h_TZ0k31WCIOlcn7uVDQQkf_taBOqoNH4QAO-_bJoXDlpa3Eud1neYX0vPrWfhiBf_FjcbmNaHioHZOO1R-OUAGrYyZcU9h5N8rvcmPyQmcsyIEN0p6PyZgTOd6ww/s200/Donald.Duck.copyrightDisney.gif" width="190" /></a>Why this happens is still not completely understood. Ophthalmologists Michael F. Marmor and James G. Ravine, authors of the new book “The Artist’s Eyes: Vision and the History of Art,” suggest a psychological cause: “Our judgment of the direction of someone’s eyes is linked, in part, to the direction we believe that person to be looking.”<br /><br />This might explain why cartoon eyes drawn "crosseyed" still seem to be looking at us. <br />------<br /><a href="http://www.amazon.com/Artists-Eyes-Vision-History-Art/dp/0810948494/ref=sr_1_fkmr0_1?ie=UTF8&qid=1304700420&sr=1-1-fkmr0"><i>The Artist’s Eyes: Vision and the History of Art</i> by Marmor and Ravine</a><br />William Hyde Wollaston, <a href="http://www.jstor.org/pss/107715"><i>Apparent Direction of Eyes in a Portrait</i></a><br />Donald Duck is copyright <a href="http://www.blogger.com/goog_1680357987">Disney.</a><i><a href="http://disney.go.com/index">http://disney.go.com/index</a> </i><br />-----<br />Don’t forget to vote in the video contest (scroll down to view the videos).

Gaze Direction

Which way are these eyes looking? Do they seem to be looking right at you, or off to the side? Our perception of gaze direction is influence...

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Lines and the Brain, Part 4

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOYkvHVYiu5WoBPhqF6QmZxQ-ryt6ygdOZHAm9mziziEaV-oYTVxmRlO1FjSFZCgHrvpNsesF2f3xXFpAHAGr0_P2NQCR_eRj0hs9Rq1iGYQDZ44IzS98sexDATG5w0RZ3iTPmsGoDBjM/s1600/Kanisza_Square_Illusion.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a>In a previous post, I mentioned that the visual brain uses a lot of cues, not just lines, to piece together its understanding of the world.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOYkvHVYiu5WoBPhqF6QmZxQ-ryt6ygdOZHAm9mziziEaV-oYTVxmRlO1FjSFZCgHrvpNsesF2f3xXFpAHAGr0_P2NQCR_eRj0hs9Rq1iGYQDZ44IzS98sexDATG5w0RZ3iTPmsGoDBjM/s1600/Kanisza_Square_Illusion.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOYkvHVYiu5WoBPhqF6QmZxQ-ryt6ygdOZHAm9mziziEaV-oYTVxmRlO1FjSFZCgHrvpNsesF2f3xXFpAHAGr0_P2NQCR_eRj0hs9Rq1iGYQDZ44IzS98sexDATG5w0RZ3iTPmsGoDBjM/s1600/Kanisza_Square_Illusion.gif" /></a><br />Even in the absence of outlines, we easily and automatically register shapes. The Kanisza square illusion shows that certain arrangements of forms create the perception of a shape where no line exists.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgfPTuDklzAa3cF6KsSuf4DousoyuUdWCyAhyphenhyphenhQ1oXz6tK3lj0nE-QSfOPCXY_o_yb9qfxAof6QyFtbaqqX2rLwmgB7F715JXJpCU07sXmyDEkALhiB4pfYqKPxSewdbSZJW0xs3sk8kPU/s1600/Coles_Phillips.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgfPTuDklzAa3cF6KsSuf4DousoyuUdWCyAhyphenhyphenhQ1oXz6tK3lj0nE-QSfOPCXY_o_yb9qfxAof6QyFtbaqqX2rLwmgB7F715JXJpCU07sXmyDEkALhiB4pfYqKPxSewdbSZJW0xs3sk8kPU/s1600/Coles_Phillips.jpg" /></a><br />Coles Phillips was a Golden Age illustrator who used this phenomenon as a compositional device, making our brains see what isn’t there. He became known for the “Fadeaway Girl,” who disappears into the background.<br />------<br />Don't forget, Sunday is the deadline for the <a href="http://gurneyjourney.blogspot.com/2011/02/book-trailer-contest.html">book trailer video contest!</a><br />Lines and the Brain Series,<br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-1.html">Part 1</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-2.html">Part 2</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-3.html">Part 3</a><br /><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-4.html">Part 4</a>

Lines and the Brain, Part 4

In a previous post, I mentioned that the visual brain uses a lot of cues, not just lines, to piece together its understanding of the world. ...

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Lines and the Brain, Part 3

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp4P9hbBf88dLdR8nLHPgIOBPcG8YD3i5VKgTfItb1EXDIt-RhbtblEFgkxemtWwFpqGqesBwpSSPjRDjqjKxNL9KqbTzyjKQwG3iKUlcWJB4ZiGcIdKDkhbZakRvtmtKQh1C29pUi4i0/s1600/Orientation_Columns_Visual_Cortex.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp4P9hbBf88dLdR8nLHPgIOBPcG8YD3i5VKgTfItb1EXDIt-RhbtblEFgkxemtWwFpqGqesBwpSSPjRDjqjKxNL9KqbTzyjKQwG3iKUlcWJB4ZiGcIdKDkhbZakRvtmtKQh1C29pUi4i0/s1600/Orientation_Columns_Visual_Cortex.jpg" /></a><br />However you define them, lines or edges are an exciting topic now because of new breakthroughs in vision science. Neuroimaging and other tools used to analyze brain function are rapidly increasing the understanding of how the visual system interprets the lines we encounter in the world around us. <br /><br />The primary visual cortex, which lies at the back of the brain, has about 140 million neurons. These neurons are organized in groups that specialize in sorting the information into various properties. Some groups of neurons called orientation columns respond preferentially to vertical lines, some to horizontal lines. In the image at left, created from the visual cortex of a macaque monkey, neural clusters with different functions are grouped by color. Other clusters of neurons respond to size, color, and shape. Some are tuned to respond to vertical movement, and others to radial movement.<br /><br />I asked Carl Schoonover: <br />Do the orientation columns perceive a vertical line as vertical even if the head is tilted or if the lines are receding in three point perspective?<br /><br />“Orientation columns perceive orientation relative to the patterns of light that hit the retina. So if look at a vertical line and tilt your head 90 degrees, neurons that respond to vertical lines will go silent (aka that orientation column will go silent), whereas previously 'horizontal-preferring' silent neurons/orientation columns will then be activated. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiWFwZcI_uIQifLt7APJco1PUkO5NNpgs7-D9RjHhcJE35KsYlPTflxnHRpZWaZDoMEhz2jpGgwcSK3Bi3P8eR6Bqv6r3e9ueiYI5NoBLDDCZjGl8LzT312gvY8oqm_u4NfFi3TMTY4TM/s1600/Berkey.Calendar.1979.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiWFwZcI_uIQifLt7APJco1PUkO5NNpgs7-D9RjHhcJE35KsYlPTflxnHRpZWaZDoMEhz2jpGgwcSK3Bi3P8eR6Bqv6r3e9ueiYI5NoBLDDCZjGl8LzT312gvY8oqm_u4NfFi3TMTY4TM/s400/Berkey.Calendar.1979.jpg" width="400" /></a><br />“However, you may still perceive the vertical line as vertical, even if your head is tilted. This is because there's a lot more to the visual system than just one-to-one representation of visual space onto cortical space. In higher areas of processing, it is possible to maintain a more flexible representation of one's environment, irrespective of the exact pattern of light hitting the retina.” <br /><br />“This is thanks in part to 'Helmholtzian' signals” (a centuries-old hypothesis that posits the stability of images despite our head movements). “This is useful for many reasons--for one, our heads our constantly moving as we walk, as our eyes saccade across visual space... but nonetheless our visual experience remains quite stable.”<br /><br />I'll take a brief break tomorrow (Friday) and finish this up on Saturday.<br /> ------<br /><a href="http://onlinelibrary.wiley.com/doi/10.1002/cne.901770302/abstract">More on orientation columns from the Journal of Comparative Neurology</a><br /><a href="http://crystilogic.tumblr.com/post/3390410875/yevgeniy-b-sirotin-and-aniruddha-das">Orientation columns image by Yevgeniy B. Sirotin and Aniruddha Das</a><br />Painting by John Berkey for a 1979 Brown and Bigelow calendar. Thanks, <a href="http://pinkoski.com/Articles/John-Berkey-Artwork.html">Jim Pinkowski, who has a big website</a> of Berkey images.<br />Thanks, <a href="http://www.amazon.com/Portraits-Mind-Visualizing-Antiquity-Century/dp/0810990334/ref=sr_1_1?ie=UTF8&s=books&qid=1304002104&sr=1-1">Carl Schoonover. More in his book "Portraits of the Mind"</a><br /><br />Lines and the Brain Series,<br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-1.html">Part 1</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-2.html">Part 2</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-3.html">Part 3</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-4.html">Part 4</a>

Lines and the Brain, Part 3

However you define them, lines or edges are an exciting topic now because of new breakthroughs in vision science. Neuroimaging and other too...

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Lines and the Brain, Part 2

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhWe1Jx2DnZsaHYL8EILdmOafja7lfqOuPUl511RN7j4K3UvqmPe5wmoNN1aX62QdmBsjFqHQbWT3ymfyNaetELW26TVVvaL-IjKdnb55EGfPNyjWkzpeWxQeGHoIzot4iOxyEBQN_PIs/s1600/Picasso_Line.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="194" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhWe1Jx2DnZsaHYL8EILdmOafja7lfqOuPUl511RN7j4K3UvqmPe5wmoNN1aX62QdmBsjFqHQbWT3ymfyNaetELW26TVVvaL-IjKdnb55EGfPNyjWkzpeWxQeGHoIzot4iOxyEBQN_PIs/s200/Picasso_Line.png" width="200" /></a> To artists, a line is a powerful geometric entity, whether it’s a straight or curved mark on a piece of paper. According to the author on neurobiology Carl Schoonover, the drawing by Picasso at left shows that we can distinguish shapes easily with a few lines, which he says “taps into our visual system's predilection for line.”<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhWe1Jx2DnZsaHYL8EILdmOafja7lfqOuPUl511RN7j4K3UvqmPe5wmoNN1aX62QdmBsjFqHQbWT3ymfyNaetELW26TVVvaL-IjKdnb55EGfPNyjWkzpeWxQeGHoIzot4iOxyEBQN_PIs/s1600/Picasso_Line.png" style="margin-left: 1em; margin-right: 1em;"></a><br />Yesterday I started to pose a few questions: Are lines merely abstract constructions—artificial conventions—that we have invented to represent nature? Do they have counterparts in the real world and in our minds? Do they reflect something basic going on in our brain when we look at the world?<br /><br />These can be sensitive questions for artists who do most of their work in line. They are often made to feel that what they do is just a preliminary step, or that it isn’t as advanced as what a painter does. In fact, the management of line is one of the most sophisticated skills an artist can master, and it corresponds to some of the most basic and powerful experiences of visual perception.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoWYWuwAtzZsEErkvKi7XLsy0_gAWCR3oCMGVdS5WGnLlJkDc8TDvxfxb-y1BkR0YLXZYMo7u1BWJvgteUEBuM-PbXx8Zv3G3FGpLV09HDFFNKdB6TdT42OZklKKe_ijKJ2YO2_ao4al8/s1600/Colored+Cube_Lines.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="185" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoWYWuwAtzZsEErkvKi7XLsy0_gAWCR3oCMGVdS5WGnLlJkDc8TDvxfxb-y1BkR0YLXZYMo7u1BWJvgteUEBuM-PbXx8Zv3G3FGpLV09HDFFNKdB6TdT42OZklKKe_ijKJ2YO2_ao4al8/s200/Colored+Cube_Lines.jpg" width="200" /></a><br />We use lines to describe several things:<br />1.  A boundary of a form (B, above).<br />2. An edge of a surface marking (A). <br />3. A plane change within a form (C). <br />4. Or an edge of a cast shadow (D).<br />5. Also, a line can describe a thin form, like a tree branch or a piece of spaghetti. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQvFeIEwrMahTfkOR6MsxzbYpKgf2ixOMVOKF7xdODtmgFeMdO9DNys2WCn_coPI2kEgJJD_LV3p3dSE1cyJP7Qm2WAj-TxTGfK2y5n_LTXOM5eoST059Ltr7YMDf_UAQDC1QWEWOPS2k/s1600/Poster_Design.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQvFeIEwrMahTfkOR6MsxzbYpKgf2ixOMVOKF7xdODtmgFeMdO9DNys2WCn_coPI2kEgJJD_LV3p3dSE1cyJP7Qm2WAj-TxTGfK2y5n_LTXOM5eoST059Ltr7YMDf_UAQDC1QWEWOPS2k/s200/Poster_Design.jpg" width="149" /></a><br /><br />A shape boundary can be regarded as a type of line. Some images, like this poster by Maxfield Parrish, can be made up entirely of overlapping shapes.<br /><br />At the initial level of visual processing, neuron groups in the visual cortex begin to process shape boundaries in a similar way that they process outlines drawn on white paper. But as we'll see in later posts, edge detection is just one preliminary step in object recognition. The brain constructs an understanding of shape and form and space by combining information from many different cues.<br /><br /><br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJicy-1lKj6EmztNgUz7d02dE_SubOwzD7m1fIg4lf5uXY1h1quIg2BTsncq9n9Xkwol9fSgmSVxtopgfofroAN778_hpCGtjlGH3Hwo4SylRPVbq6q6FUb-6yvVpAz_1idFQmNBQBOgI/s1600/Edge_Detection_Photograph.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="132" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJicy-1lKj6EmztNgUz7d02dE_SubOwzD7m1fIg4lf5uXY1h1quIg2BTsncq9n9Xkwol9fSgmSVxtopgfofroAN778_hpCGtjlGH3Hwo4SylRPVbq6q6FUb-6yvVpAz_1idFQmNBQBOgI/s400/Edge_Detection_Photograph.jpg" width="400" /></a><br />Our visual system has no trouble sorting out boundaries, surface marks, plane changes, and cast shadows (click to enlarge). But they are not trivial tasks when you’re trying to educate a computer, even a smart computer, to see. Edge detection and feature extraction are exciting frontiers for people at the intersection of computer science and visual perception. <br />----<br />That last photo is from <a href="http://en.wikipedia.org/wiki/Edge_detection">Wikipedia on Edge Detection</a><br />Colored cube is from GurneyJourney "<a href="http://gurneyjourney.blogspot.com/2010/01/color-constancy.html">Color Constancy Illusion</a>" post.<br /><br />Lines and the Brain Series,<br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-1.html">Part 1</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-2.html">Part 2</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-3.html">Part 3</a><br /><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-4.html">Part 4</a>

Lines and the Brain, Part 2

 To artists, a line is a powerful geometric entity, whether it’s a straight or curved mark on a piece of paper. According to the author on n...

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Lines and the Brain, Part 1

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjviUU1y-c5umf6GDIMfGKvSMBu9Y5XSKiHaB55SyDvgdLT8ReArKsspiPc27nz8CqLoLwiS1ajS9HKIu5eVLUDRQ16bbQ3rk_CLKG1DqWDd2oNadq56ICjY6aJgmjuFAuO5MghSdyluwU/s1600/Vanderpoel_Hand.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjviUU1y-c5umf6GDIMfGKvSMBu9Y5XSKiHaB55SyDvgdLT8ReArKsspiPc27nz8CqLoLwiS1ajS9HKIu5eVLUDRQ16bbQ3rk_CLKG1DqWDd2oNadq56ICjY6aJgmjuFAuO5MghSdyluwU/s200/Vanderpoel_Hand.jpg" width="123" /></a>“There are no lines in nature, only areas of color, one against another” <a href="http://www.searchquotes.com/quotation/There_are_no_lines_in_nature,_only_areas_of_colour,_one_against_another./136380/">said Edouard Manet</a>.<br /><br />Perhaps not. But by the same logic there are no colors in nature, either.<br /><br />Lines and colors are phenomena that manifest themselves in our our minds. At that level, lines are very real indeed. Perceiving boundaries is a fundamental aspect of our life as visual creatures. It is hard-wired into our perception.<br /><br />According to <strike>neuroscientist</strike> neuroscience PhD candidate <a href="http://www.carlschoonover.com/#">Carl Schoonover: </a><br /><br />“Lines are the bread and butter of our visual experience. They define trees, horizons, the edges of things we don’t want to bump into. Our visual system is designed to rapidly extract this meaningful information in order to make sense of the world. Consequently, the area in the visual cortex that first processes information coming in from the eyes is configured in a manner that reflects this preference for lines.” <br />---------<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgWfYnO8Dd-ShMyd5O9ue_XpINpRlG5IDKB9SpVXcX1i1g1HCF5QZ98YRHHiwK6dS6PBWGfA44q8JJQDgiH9Qzzuom4bq1fPW3Z_81qQHlrKkRtlmIw7UIHo9XuN3UqHnOINzUQ3LOYo8/s1600/Norton.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgWfYnO8Dd-ShMyd5O9ue_XpINpRlG5IDKB9SpVXcX1i1g1HCF5QZ98YRHHiwK6dS6PBWGfA44q8JJQDgiH9Qzzuom4bq1fPW3Z_81qQHlrKkRtlmIw7UIHo9XuN3UqHnOINzUQ3LOYo8/s200/Norton.jpg" width="195" /></a>Quote from Carl Schoonover in<a href="http://www.amazon.com/Portraits-Mind-Visualizing-Antiquity-Century/dp/0810990334/ref=sr_1_1?s=books&ie=UTF8&qid=1303830330&sr=1-1"> “Portraits of the Mind,”</a> (2010) <br />Images from:<br /><a href="http://books.google.com/books?id=PKvUAAAAMAAJ&printsec=frontcover&dq=the+human+figure+by+vanderpoel&hl=en&ei=A9-2TfKwOMaugQfh0PTeCg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDwQ6AEwAA#v=onepage&q&f=false">Vanderpoel, The Human Figure, 1908</a><br /><a href="http://books.google.com/books?id=bP8jAAAAMAAJ&printsec=frontcover&dq=freehand+perspective+and+sketching&hl=en&ei=xt62TYfUHpHpgQeU2b3KDA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CEoQ6AEwAA#v=onepage&q&f=false">Norton,  Freehand Perspective and Sketching</a><br /><br />Lines and the Brain Series,<br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-1.html">Part 1</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-2.html">Part 2</a><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-3.html">Part 3</a><br /><br /><a href="http://gurneyjourney.blogspot.com/2011/04/lines-and-brain-part-4.html">Part 4</a>

Lines and the Brain, Part 1

“There are no lines in nature, only areas of color, one against another” said Edouard Manet . Perhaps not. But by the same logic there are n...

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Bert Untooned

What would <a href="http://en.wikipedia.org/wiki/Bert_%28Sesame_Street%29">Bert</a> from Sesame Street look like if you kept his cartoon proportions but made him otherwise real?<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyA_EdoHSiEEzhbsvBLWzlCVSdx0ewdhbXgmAHMzFkFEGvzKG5hbOf16Ui9Y6JuPBZlPgnJjWG_VaWfcXKrWqkQYgR9fNk-RS67mwsvfIL4rJZNxu3iksWAzHAnJzwaDXptp4qk26uYto/s1600/WyethOnTheIslandofEarraid.det.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"></a><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEkT0XCliWUnE4qSXaEOXE8nPrGb1Nbef7ROjHjpP0XfI55npzst6oUKEpdeJmjeJaYW2UltFTqeKpO3CmKP-WcIuPSlRNl7xTpbRexEbiMD-PK6b-9O0vgkL9i1SQmGUPMYUMNx6r6VA/s1600/Bert_Untooned.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="263" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEkT0XCliWUnE4qSXaEOXE8nPrGb1Nbef7ROjHjpP0XfI55npzst6oUKEpdeJmjeJaYW2UltFTqeKpO3CmKP-WcIuPSlRNl7xTpbRexEbiMD-PK6b-9O0vgkL9i1SQmGUPMYUMNx6r6VA/s400/Bert_Untooned.JPG" width="400" /></a><br />He’s still got those caterpillar eyebrows, bug eyes, top tuft, bulbous nose and wide grin. But when we see all his details and textures, he has an altogether different charm—or creepiness. <br /><br />“<a href="http://www.google.com/search?q=untooning&oe=utf-8&rls=com.yahoo:en-US:official&client=firefox&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&hl=en&tab=wi&biw=1089&bih=523">Untooning</a>” has been a hot internet meme over the last few years, and it raises all sorts of questions about verisimilitude.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyA_EdoHSiEEzhbsvBLWzlCVSdx0ewdhbXgmAHMzFkFEGvzKG5hbOf16Ui9Y6JuPBZlPgnJjWG_VaWfcXKrWqkQYgR9fNk-RS67mwsvfIL4rJZNxu3iksWAzHAnJzwaDXptp4qk26uYto/s1600/WyethOnTheIslandofEarraid.det.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyA_EdoHSiEEzhbsvBLWzlCVSdx0ewdhbXgmAHMzFkFEGvzKG5hbOf16Ui9Y6JuPBZlPgnJjWG_VaWfcXKrWqkQYgR9fNk-RS67mwsvfIL4rJZNxu3iksWAzHAnJzwaDXptp4qk26uYto/s1600/WyethOnTheIslandofEarraid.det.jpg" /></a><br />A face that has been abstracted can be just as real to us emotionally, maybe more so. Think of African masks. Character designers at CGI animation studios are also very conscious of dialing down the realism on human characters. Too much realism can drop us into the <a href="http://en.wikipedia.org/wiki/Uncanny_valley">uncanny valley</a>. <br /><br />I think the same thing is true of storytelling paintings, such as this illustration by N.C. Wyeth from <i>Kidnapped.</i> It’s more of a mental image he was striving for. By not showing his eyes, Wyeth makes David Balfour seem more lost in the fog. <br />----------<br />Bert from <a href="http://www.boingboing.net/2011/04/21/bert.html">BoingBoing </a><br />See Mario, Charlie Brown, and other Untooned characters at <a href="http://www.huffingtonpost.com/2010/01/04/untooned-cartoon-characte_n_410448.html?slidenumber=Z9ksyxqowJ0%3D&slideshow#slide_image">Huffington Post </a><br />Related GJ post about <a href="http://gurneyjourney.blogspot.com/2009/12/face-detection.html">camera face detection </a>

Bert Untooned

What would Bert from Sesame Street look like if you kept his cartoon proportions but made him otherwise real? He’s still got those caterpil...

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Mimetoliths

There's a name for them: mimetoliths. They're rock formations that look like faces or other living things.<br /><br /> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL5H6IegGHA68wwYMittX13bEauP4sp1oqqpOF9t3BXJzMWJTSCr5u2HMwymdrtAd-3RdpPi58RaQ_iP1pVQB3uCGuEN4CKW4JY7mu519C72WccrRpaS6hDFY9W_W8TqEKAAxNeAyLglM/s1600/grey_man_of_merrick.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="310" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL5H6IegGHA68wwYMittX13bEauP4sp1oqqpOF9t3BXJzMWJTSCr5u2HMwymdrtAd-3RdpPi58RaQ_iP1pVQB3uCGuEN4CKW4JY7mu519C72WccrRpaS6hDFY9W_W8TqEKAAxNeAyLglM/s400/grey_man_of_merrick.jpg" width="400" /></a><br />The Grey Man of Merrick sits at the base of Merrick mountain in Scotland's Galloway Forest Park.<br /> <a href="http://www.wired.com/wiredscience/2011/03/rock-people-gallery/">See more examples at Wired Science</a><br /><br />Related post on Gurney Journey: <a href="http://gurneyjourney.blogspot.com/2008/06/pareidolia-and-apophenia.html">Pareidolia and Apophenia</a><br /> Thanks, <a href="http://www.studiorousar.com/">Darren R.</a>

Mimetoliths

There's a name for them: mimetoliths. They're rock formations that look like faces or other living things.   The Grey Man of Merrick...

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First Impressions

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSZtam2gwtCb__dfogegnMolqe0_FGtLxW1jNWHg1ci0_sH0zGe5LyOJmhHoMfmhHdqO5a6aALRO49OJTTBGbYBCSIxHpgsDuMt5hFPX2V-gr7UljC3zV1iIBu6Se6UTHZizmmdrt2iKs/s1600/East.Night_In_Cotswolds.vsm.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a>Some people define “impressionism” as an approach to painting where the goal is to capture the first perception of a scene. The World Book Encyclopedia says that “impressionist painters try to show what the eye sees at a glance.”<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY8GEbgURDqeAtznXCg6_9LjrHMNJ6MXB_r_avvfqdhXMJ9p-AG5lJCU0i9dULKTFW4dljT4WnTvO6kFb_WTIpmUpfv7x5dig7jszUzCs9oRCBeTWnFRpexwl2yG7PR5TauQk03J4kYdU/s1600/Monet_-_Graystaks_I.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="313" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY8GEbgURDqeAtznXCg6_9LjrHMNJ6MXB_r_avvfqdhXMJ9p-AG5lJCU0i9dULKTFW4dljT4WnTvO6kFb_WTIpmUpfv7x5dig7jszUzCs9oRCBeTWnFRpexwl2yG7PR5TauQk03J4kYdU/s400/Monet_-_Graystaks_I.JPG" width="400" /></a><br />The first-glance impact is usually represented by an image with simple masses of color, painted with big brushstrokes without much detail, often with soft edges between the masses, such as this haystack painting by Monet. <br /><br />Typically, “impressionist” images have high-chroma dabs of color that resolve into a larger blurry image. Recognizable small details are conspicuously left out.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMkS84EOIAOs8PTzMQEzM3YQ7kp4P5AKzDb-GJl4BvMau7s0C7CiIaQQlrOMYewehQlHjQxu21A5dXRyfG1B6JjOrFPq3epaEH2tEoCjTav_COn3hh6IN2G19QL9TuQbq5r9ly4AUOA8M/s1600/Impression.Scene.sm.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMkS84EOIAOs8PTzMQEzM3YQ7kp4P5AKzDb-GJl4BvMau7s0C7CiIaQQlrOMYewehQlHjQxu21A5dXRyfG1B6JjOrFPq3epaEH2tEoCjTav_COn3hh6IN2G19QL9TuQbq5r9ly4AUOA8M/s400/Impression.Scene.sm.jpg" width="400" /></a><br />We’re told that this is how the eye perceives on the first glance. Let me see if I can simulate this idea using a photographic image. Here’s an unaltered photo of a street scene.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQBAHbChND5NREiEqpOMt7037Wi77_9IFNdCIq9I6Yku2uXUNAwGX63K-XFRrLLg-CHKC8Y5-8aHhzo7Hc_HryypEn1Fg9Yr2FcxSHyJm9BWpplcbatGwkuFZfLV9eJaujEyutXRTF6NM/s1600/ImpressionB.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQBAHbChND5NREiEqpOMt7037Wi77_9IFNdCIq9I6Yku2uXUNAwGX63K-XFRrLLg-CHKC8Y5-8aHhzo7Hc_HryypEn1Fg9Yr2FcxSHyJm9BWpplcbatGwkuFZfLV9eJaujEyutXRTF6NM/s400/ImpressionB.jpg" width="400" /></a><br />Here’s an “impressionist” take on the same scene (using the Photoshop filter “paint daubs” and a heightened color saturation).<br /><br />I believe there are some assumptions here that need examining. Does our first impression really look like an impressionist painting?<br /><br />If I’m really honest about my own experience of vision, my first-glance take on a scene is nothing at all like a Monet. What I see in the first two or three seconds are a few extremely detailed but disconnected areas of focus. Small individual elements, such as a sign, a face, or a doorknob, take on particular importance immediately, perhaps because the left-brain decoding process (seeing in symbols) is so heavily engaged in the first few seconds.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRFcenrJtuPC_SAr_dccobUmtoRl73a6_PslmMZ2txBL1QMWQPfTpZAaMxdHpDnHh-RNBMKXpzFQu4P1W3jc0m0eOH-mw6zbqJ3UX7Wv4t8vnQdv-V8cPHmrotARrafxn-bJRg9Jr2xSA/s1600/ImpressionA.sm.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRFcenrJtuPC_SAr_dccobUmtoRl73a6_PslmMZ2txBL1QMWQPfTpZAaMxdHpDnHh-RNBMKXpzFQu4P1W3jc0m0eOH-mw6zbqJ3UX7Wv4t8vnQdv-V8cPHmrotARrafxn-bJRg9Jr2xSA/s400/ImpressionA.sm.jpg" width="400" /></a><br />I’ve altered the photo to try to simulate this experience by sharpening and heightening these disconnected elements. What happens in the first few seconds for you? I don’t know how other people see, because I’m stuck inside my own head. Perhaps eye-tracking and fMRI studies can help us to better understand what really happens cognitively in the first few second of visual perception. Maybe it varies widely from person to person. <br /><br />What I’m questioning is not the artistic tradition of impressionism, but rather our habits of thinking about it. The idea of trying to capture the broad, simple masses of a scene is a valid artistic enterprise. But even though I’m a plein air painter with impressionist leanings, I believe that kind of seeing emerges only after sustained, conscious effort and training, or not at all.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSZtam2gwtCb__dfogegnMolqe0_FGtLxW1jNWHg1ci0_sH0zGe5LyOJmhHoMfmhHdqO5a6aALRO49OJTTBGbYBCSIxHpgsDuMt5hFPX2V-gr7UljC3zV1iIBu6Se6UTHZizmmdrt2iKs/s1600/East.Night_In_Cotswolds.vsm.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="273" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSZtam2gwtCb__dfogegnMolqe0_FGtLxW1jNWHg1ci0_sH0zGe5LyOJmhHoMfmhHdqO5a6aALRO49OJTTBGbYBCSIxHpgsDuMt5hFPX2V-gr7UljC3zV1iIBu6Se6UTHZizmmdrt2iKs/s400/East.Night_In_Cotswolds.vsm.jpg" width="400" /></a><br />Above: Sir Alfred East, “Night in the Cotswalds.”<br /><br />Perceiving big shapes requires a deliberate act of defocusing or squinting. These are rather unnatural kinds of perception. When I squint and defocus on a subway, people look at me like I’m insane. Painting teachers know that students don’t see the big masses naturally. They need to be taught to do it. <br /><br />(Incidentally, this big-mass mode of artistic seeing was very much a part of 19th century academic training, and was by no means exclusive to the Impressionists—but that’s another topic.) <br /><br />I realize that the term “impressionism” was not coined by the artists, but rather by their critics. In any event the word and that sense of the word have become irrevocably associated with the movement. Of course the word has other definitions, such as the portrayal of transient effects of light and color, or a painting style using short brush strokes, and those meanings of the word are valid. <br /><br />But the notion that impressionist paintings are accurate representations of our first visual impressions strikes me as false dogma. I’m skeptical of the word when it’s used in that sense. <br /><br />“Impressionism,” whatever its merits as a mode of picture making, may not describe a universal experience of perception, so much as a particular style of painting.<br />----------<br />Related previous posts on GurneyJourney:<br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-1.html">Eyetracking and Composition, part 1 </a><br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-2.html">Eyetracking and Composition, part 2 </a><br /><a href="http://gurneyjourney.blogspot.com/2009/09/eye-tracking-and-composition-part-3.html">Eyetracking and Composition part 3</a><br />Introduction to eyetracking, <a href="http://gurneyjourney.blogspot.com/2009/02/what-are-you-looking-at.html">link.</a><br />How perception of faces is coded differently, <a href="http://gurneyjourney.blogspot.com/2008/05/never-forget-face.html">link.</a>

First Impressions

Some people define “impressionism” as an approach to painting where the goal is to capture the first perception of a scene. The World Book E...

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Smart Tracking Camera

<iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/1GhNXHCQGsM" title="YouTube video player" width="480"></iframe><br />New technology allows a camera to track an eye, a particular face, or any other specified object.  <br /><br />The inventor, Zdenek Kalal, takes it through its paces, showing how it can learn and adapt to a lot of tracking challenges. <br /><br />The ominously named “Predator” has strong potential for autonomous driving systems, military targeting, consumer photography, wildlife filming, FX compositing, surveillance videography, image stabilization, industrial robots, and human/computer interface technology.  <br /><br />The field of machine vision is still in its infancy and largely limited so far to industrial applications. We’ve grown accustomed to surveillance cameras filming us. Next we’ll have to get used to seeing machines that recognize us and keep an eye on us.<br />-------<br />Via <a href="http://bestofyoutube.com/">Best of YouTube</a><br />More at <a href="http://www.wired.com/gadgetlab/2011/04/predator-smart-camera-locks-on-tracks-anything-mercilessly/">Wired.com's Gadget Lab</a>

Smart Tracking Camera

New technology allows a camera to track an eye, a particular face, or any other specified object.  The inventor, Zdenek Kalal, takes it thro...

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See-Through Square

<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ3AuDxrkkr6QOGhhzVojAEZgdDxYgg5aE4iI5OU-isL_oK2XFZjXNLAy-QGb5ZzC4hImSfHdSXtKlDCuDUes3tKfXXQN0pkPmzSM0_XO-t_SRk6nk7qmFJWApdU4KpiLz8eg2uucCNr0/s1600/Watercolor_Illusion_Spillmann.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><br /></a></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiosUwPKAbtDUtk1YYZvLDUhUfN17YBImJ7hXoN9XNgqvD4-ihwXAup-S70PB0Jdpgqrk99R0Al17UTG8fy1FWep0__rMNamXjNtS_FU3VwS7XmN_euQnPkuhAv58iGLgBGfxs7CS7PrOc/s1600/See_Through_Square.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="94" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiosUwPKAbtDUtk1YYZvLDUhUfN17YBImJ7hXoN9XNgqvD4-ihwXAup-S70PB0Jdpgqrk99R0Al17UTG8fy1FWep0__rMNamXjNtS_FU3VwS7XmN_euQnPkuhAv58iGLgBGfxs7CS7PrOc/s200/See_Through_Square.JPG" width="200" /></a><br />Here’s a fun experiment. Cut out a square of bright colored paper about two or three inches across. <br /><br />Hold the square about four inches from your eyes. Let some light shine on the side of the square you’re looking at, so that the color appears vibrant. Now, keeping both eyes open, look off to a scene in the distance.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqUvqBoDkKSO_Md7AzP4BBdAmuT09lp4bpOXHdVNQHT0PXQyXWwMXgDmCqaaX8hKbT8pw-6G0nJV9pBMTvOiQ2j1x9AbiLXwiYp59CwyNVx7SqbFu90tGQzkzlleNxi2pIE-ETU9y6NXY/s1600/SeeThrough.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="275" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqUvqBoDkKSO_Md7AzP4BBdAmuT09lp4bpOXHdVNQHT0PXQyXWwMXgDmCqaaX8hKbT8pw-6G0nJV9pBMTvOiQ2j1x9AbiLXwiYp59CwyNVx7SqbFu90tGQzkzlleNxi2pIE-ETU9y6NXY/s400/SeeThrough.jpg" width="400" /></a><br />You may notice that the square appears transparent in the middle but opaque at the edges. Here’s the effect simulated in Photoshop.<br /><br />The reason, according to vision scientist Dr. Margaret Livingstone of Harvard, is that our color receptors respond to color borders, but they tend to disregard flat, homogenous areas of color. <br /><br />Our color system codes a color area by establishing its color contrast at the edges of the area, and then fills in perceptually. Even though a tomato is colored red equally at its edges and at its center, we only get information about its color from the edges. We don’t  get any direct information from the red in the center at all. <br /><br />The color spills into the center of a form from the edges, an effect called "color assimilation."<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ3AuDxrkkr6QOGhhzVojAEZgdDxYgg5aE4iI5OU-isL_oK2XFZjXNLAy-QGb5ZzC4hImSfHdSXtKlDCuDUes3tKfXXQN0pkPmzSM0_XO-t_SRk6nk7qmFJWApdU4KpiLz8eg2uucCNr0/s1600/Watercolor_Illusion_Spillmann.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="238" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ3AuDxrkkr6QOGhhzVojAEZgdDxYgg5aE4iI5OU-isL_oK2XFZjXNLAy-QGb5ZzC4hImSfHdSXtKlDCuDUes3tKfXXQN0pkPmzSM0_XO-t_SRk6nk7qmFJWApdU4KpiLz8eg2uucCNr0/s320/Watercolor_Illusion_Spillmann.gif" width="320" /></a><br />The phenomenon is also illustrated by the “watercolor illusion” by Lothar Spillmann, where colors along the border of a shape seem to leak into the shape, and we perceive a tint of color throughout the shape, even if it’s not really there.<br /><br />In our experiment with the colored squares, the information from the far-seeing eye takes over where the near-seeing eye is getting no data, giving preference to the scene. At the edges of the square, the color border information from the near-seeing eye takes precedence, making the square seem opaque. <br />-----------<br /><a href="http://www.journalofvision.org/content/6/5/7.full">“Watercolor illusion” Lothar Spillman on Journal of Vision</a><br /><a href="http://www.amazon.com/Vision-Art-Margaret-S-Livingstone/dp/0810995549/ref=sr_1_1?s=books&ie=UTF8&qid=1302013346&sr=1-1">Vision and Art: The Biology of Seeing by Margaret Livingstone</a>

See-Through Square

Here’s a fun experiment. Cut out a square of bright colored paper about two or three inches across. Hold the square about four inches from y...

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Disney uses lab tests to gauge response to ads.

According to <a href="http://www.variety.com/article/VR1118033334">Variety magazine</a>, the Disney company is working with a scientific laboratory known as the “Disney Media and Advertising Lab” or “Ad Lab” to analyze audience response to the ads appearing on its networks. <br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiOv4xMKhRep_PU_bxNTcXPGiJcvfAg1MBPPodRR7cr9bkN6C8-cciADh9w1N4NKkI7moyDxxpbDlrSyI0PjGtYFQlKH3W9bomjjxVft0yoE46TepsFFvbZYHPz58i3E295H3pHL_qs_o/s1600/weekly_disneytech1.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="159" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgiOv4xMKhRep_PU_bxNTcXPGiJcvfAg1MBPPodRR7cr9bkN6C8-cciADh9w1N4NKkI7moyDxxpbDlrSyI0PjGtYFQlKH3W9bomjjxVft0yoE46TepsFFvbZYHPz58i3E295H3pHL_qs_o/s320/weekly_disneytech1.jpg" width="320" /></a><br />The lab building, which does not include the Disney logo, is located in Austin, Texas. Scientists dissect biometric data about eye tracking (left image above), heart rate, and galvanic skin response to better understand emotional reactions to ad content. According to Senior VP Artie Bulgrin, these data are far more accurate than the self-reporting of questionnaires.<br /><br />Another technique called “facial coding” or “facial mapping” (right image, above) tracks tiny movements of individual facial muscles. For the future, the scientists at Ad Lab are considering including data from brain wave analysis to better understand how people respond to ads.<br /><br />The lab’s primary mandate is to study advertising strategies on behalf of ESPN, ABC, and ABC Family, helping those multi-platform media networks to coordinate better with their advertising partners. <br /><br />Ad lab studies classic metrics such as unaided recall to novel ad strategies like live ads, split screen ads, banners, and transparencies, where ads are superimposed over content.<br /><br />No word yet on whether the mouse house is using ad lab to pre-test its motion pictures.<br /><br /> <a href="http://www.adweek.com/aw/content_display/news/e3ide843f7bf07c511ff616553c57189dba%20Variety%20%E2%80%9CDisney%E2%80%99s%20Lab%20Studies%20People%E2%80%9D%20by%20David%20Cohen%20http://www.variety.com/article/VR1118033334">Adweek article on Ad Lab</a><br /><a href="http://austinist.com/2008/05/15/austin_to_house.php">"Austin to House Disney's Ad Lab"</a><br /><div class="separator" style="clear: both; text-align: left;"><a href="http://www.maldiviandigital.com/f2/disney-pulls-back-curtain-ad-lab-52095/">"Disney Pulls Back Curtain on Ad Lab"</a><a href="http://www.maldiviandigital.com/f2/disney-pulls-back-curtain-ad-lab-52095/"></a></div><a href="http://www.variety.com/article/VR1118033334">Variety article: “Disney’s Lab Studies People” by David Cohen </a>

Disney uses lab tests to gauge response to ads.

According to Variety magazine , the Disney company is working with a scientific laboratory known as the “Disney Media and Advertising Lab” o...

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Predictive Coding

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEholQl0H-KdG9Blmt87X1JHsrIkYTbxcWBruDC648sDKsP9MgEXtMGuN5zt4CegiUEmHzzwZsqy2qz_SfOgxM2zQZdXbYtEUSIo_3yi2djzeqo3rFUQPGKUvbWH__tpCyGvVykyvaHvAT8/s1600/amour_de_pierrot.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a>A new study from Duke University revises our idea of how the visual system works.  <br /><br /><b>Old idea: bottom up</b><br />According to the older idea, images are constructed in our minds in a hierarchical fashion starting at the bottom. Data arriving at the retina is sorted into basic features, such as horizontal and vertical lines. These elements gradually resolve as they pass up through the layers of neural organization. Eventually they form into complete images that we recognize as particular objects. The brain’s higher level inferences, according to this model, develop only after this bottom-up process is completed. <br /><br /> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEholQl0H-KdG9Blmt87X1JHsrIkYTbxcWBruDC648sDKsP9MgEXtMGuN5zt4CegiUEmHzzwZsqy2qz_SfOgxM2zQZdXbYtEUSIo_3yi2djzeqo3rFUQPGKUvbWH__tpCyGvVykyvaHvAT8/s1600/amour_de_pierrot.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEholQl0H-KdG9Blmt87X1JHsrIkYTbxcWBruDC648sDKsP9MgEXtMGuN5zt4CegiUEmHzzwZsqy2qz_SfOgxM2zQZdXbYtEUSIo_3yi2djzeqo3rFUQPGKUvbWH__tpCyGvVykyvaHvAT8/s320/amour_de_pierrot.jpg" width="239" /></a><br /><b>New idea: top-down</b><br />Experiments using modern brain imaging data show that the process is really quite the reverse. The new idea, called “predictive coding,” proposes that the brain develops predictions about what we’re about to see. It tests those predictions in a top-down, rather than merely a bottom-up mode. The information that we take in is edited to fit the conception. This all happens within milliseconds and is largely unconscious.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcqxYWd_cYIu1obM51u2diqGZl4QO-YiFdhWMkLKDUu5qyaGLEOkM29kcri1O9hfd90ttsCLHzkk53UDIOBfaIb9UwF5nSRAr_xzusFL_IEb_f0_tEpm9bSWyfrD1vnXKaq0VjSE-ticU/s1600/Stalagmites.sm.WT.jpg" style="margin-left: 1em; margin-right: 1em;"></a><br /><b>Neural storm</b><br />Whenever low-level input contradicts the predictions and forces us to change our reading of an object, there is a storm of neural activity. This neural storm is particularly strong with optical illusions, such as the one that began this post. You may have experienced this if you ever, in a split second, mistook a stick on the ground for a snake. The top-down expectations get quickly overwhelmed by bottom-up corrections.<br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcqxYWd_cYIu1obM51u2diqGZl4QO-YiFdhWMkLKDUu5qyaGLEOkM29kcri1O9hfd90ttsCLHzkk53UDIOBfaIb9UwF5nSRAr_xzusFL_IEb_f0_tEpm9bSWyfrD1vnXKaq0VjSE-ticU/s1600/Stalagmites.sm.WT.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="212" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcqxYWd_cYIu1obM51u2diqGZl4QO-YiFdhWMkLKDUu5qyaGLEOkM29kcri1O9hfd90ttsCLHzkk53UDIOBfaIb9UwF5nSRAr_xzusFL_IEb_f0_tEpm9bSWyfrD1vnXKaq0VjSE-ticU/s400/Stalagmites.sm.WT.jpg" width="400" /></a><br />This illustration from <i>Dinotopia: The World Beneath</i> shows this kind mental process in action. An ambiguous cave formation, left, can either be seen as a skull or a woman with babies. Depending on how the mind wants to perceive the form, the details are marshaled to match the perception. <br /><br />This phenomenon of conjuring faces and other meaningful patterns in apparently random visual data is a phenomenon that’s also called “pareidolia,” covered in an earlier post.<br /><br />Here are three suggestions for how this new theory may affect us as artists (and I'm sure you'll think of other implications:<br />1. We mostly see what we expect to see. Viewers come to your pictures unconsciously preloaded in various ways.<br />2. Much information is lost because of this automatic editing process. It never reaches our conscious minds because it's edited out. Therefore we just don’t see a huge amount (and maybe that’s a good thing at times).<br />3. Having a wrong search image can actually make us blind to what we’re looking for. For example, if you thought the book you were looking for had a blue spine, you might not even see the correct book with the red spine. <br />-----<br /><a href="http://www.dukenews.duke.edu/2010/12/egner_vision.html">Duke University news release</a><br /><a href="http://www.kurzweilai.net/brain%E2%80%99s-visual-circuits-do-error-correction-on-the-fly">Another report on predictive coding</a><br /><a href="http://www.planetperplex.com/en/scary_optical_illusion.html">First optical illusion from Planet Perplex</a><br />Related GJ Post on <a href="http://gurneyjourney.blogspot.com/2008/06/pareidolia-and-apophenia.html">Pareidolia and Apophenia: </a><br />Thanks, Rob Wood and Brad

Predictive Coding

A new study from Duke University revises our idea of how the visual system works.  Old idea: bottom up According to the older idea, images a...

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Chromatic Adaptation

Have a look at the photo of the dinosaur Bix on the right in the photo below. The colors are split down the middle, with a cyan cast on the left half and a yellowish cast on the right.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNor4jVX_edNkwsV-VPa9QCnDr5f4Dj925d3CzM6-lFzBQI89g_Hbibx81fm1t7zAYOMqzWb-QWhdzjtRSxqcMoiJiVc6r6YBXFNvjPYIWCUIZfqQ6RSbXFtd7jsQz_mssRTCxE6oVjtM/s1600/Chromatic-Illusion.sm.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="207" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNor4jVX_edNkwsV-VPa9QCnDr5f4Dj925d3CzM6-lFzBQI89g_Hbibx81fm1t7zAYOMqzWb-QWhdzjtRSxqcMoiJiVc6r6YBXFNvjPYIWCUIZfqQ6RSbXFtd7jsQz_mssRTCxE6oVjtM/s400/Chromatic-Illusion.sm.jpg" width="400" /></a><br />Now stare for 20 seconds at the little “+” on the line between the color fields on the left. (Click on the whole image to make it bigger.)<br /><br />When you look back at the "+" on the nose of Bix, the color distortions disappear and Bix looks normal, at least for a while. <br /><br />This is a demonstration of chromatic adaptation, our visual system’s “white balance” control. Whenever the illumination changes in color temperature around us, the sensitivity of our color receptors changes in relative proportion, resulting in a balanced impression of color.

Chromatic Adaptation

Have a look at the photo of the dinosaur Bix on the right in the photo below. The colors are split down the middle, with a cyan cast on the ...

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Visual Perception in IFX

The new issue of ImagineFX magazine (issue 60) has a special article that I wrote for artists on the subject of visual perception. It previews material adapted from my upcoming book, Color and Light: A Guide for the Realist Painter (November, Andrews McMeel).<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisaSKYUAPQuOUhPSFB3utAk37V5r1jW1irWaWuw9FFmN1g-eMjirHxlmD4jqvnVXANdMs5mTIGdsLmoxhsDgrAXdfw-ovymCxWEkcr9D7Ev1Uw_6o3axWHJYdAXwjVkqSvBrhDMcM2hHWt/s1600/IFX_Gurney_Visual_Perception.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5503337055253923666" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisaSKYUAPQuOUhPSFB3utAk37V5r1jW1irWaWuw9FFmN1g-eMjirHxlmD4jqvnVXANdMs5mTIGdsLmoxhsDgrAXdfw-ovymCxWEkcr9D7Ev1Uw_6o3axWHJYdAXwjVkqSvBrhDMcM2hHWt/s400/IFX_Gurney_Visual_Perception.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 243px;" /></a>The article includes both cutting-edge science and practical applications:<br />•Why moonlight looks blue. <br />•Our brains automatic “white balance” setting, and how to overcome it. <br />•How to use colour afterimages to make your paintings better.<br />•How colours are tied to emotions.<br />•Using eyetracking data to help you design better compositions.<br /><br />ImagineFX is the premier magazine for the field of science fiction and fantasy art. It usually contains a DVD with additional images and videos. <br /><br /><a href="http://www.imaginefx.com/02287754331748326369/imaginefx-issue-60.html">ImagineFX website</a><br /><a href="http://www.amazon.com/Color-Light-Guide-Realist-Painter/dp/0740797719/ref=ntt_at_ep_dpi_4">"Color and Light" book</a> on Amazon

Visual Perception in IFX

The new issue of ImagineFX magazine (issue 60) has a special article that I wrote for artists on the subject of visual perception. It previe...

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3-D Ramp Illusion

<object height="385" width="640"><param name="movie" value="http://www.youtube.com/v/hAXm0dIuyug&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/hAXm0dIuyug&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object> This video shows a 3-D optical illusion where balls appear to roll uphill. Thanks, Colin (via <a href="http://www.boingboing.net/2010/05/12/optical-illusion-imp.html">BoingBoing</a>)

3-D Ramp Illusion

This video shows a 3-D optical illusion where balls appear to roll uphill. Thanks, Colin (via BoingBoing )

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Eyetracking in International Artist

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieXEyjevR5QOScyihT1N3N6odq6Ib523BpAGrHPM2LIVkGcvqvETcBvqmGYI582wIjQYThU5LrvS2x13PKmaq_s2RisFRdQTVYeY-hPxuaZs8SbHX5XZAqDsqAh-27e10YeI1-6alGMZ6r/s1600-h/International_Artist_Eyetracking_Gurney.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5451516457267972146" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieXEyjevR5QOScyihT1N3N6odq6Ib523BpAGrHPM2LIVkGcvqvETcBvqmGYI582wIjQYThU5LrvS2x13PKmaq_s2RisFRdQTVYeY-hPxuaZs8SbHX5XZAqDsqAh-27e10YeI1-6alGMZ6r/s400/International_Artist_Eyetracking_Gurney.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 262px;" /></a><br />The new <a href="http://www.international-artist.com/iam/current.aspx">International Artist</a> magazine has a six page feature on the research on <a href="http://www.international-artist.com/iam/current.aspx">eyetracking</a> and composition that I did with the help of Greg Edwards of <a href="http://eyetools.com/">Eyetools, Inc</a>. The feature includes an extra painting that I didn't have room to analyze in <a href="http://www.amazon.com/Imaginative-Realism-Paint-Doesnt-Exist/dp/0740785508/ref=sr_1_1?ie=UTF8&s=books&qid=1252362855&sr=1-1">Imaginatiive Realism.<br /> </a><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr7LQiW3RzvB4ADfQMqN0SJdBS3BcP_O7d2KBh7o4ASb4fnRnZwpwOVLQ4T427z-26xI2z8x4c4jH2jR_fyysKVrucFq4bKHiL84P-_Ud3EDzY2jcKuCzZtzJ7OUrLmhbUYMR0C-A1LAQr/s1600-h/International_Artist.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5451514954411806018" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr7LQiW3RzvB4ADfQMqN0SJdBS3BcP_O7d2KBh7o4ASb4fnRnZwpwOVLQ4T427z-26xI2z8x4c4jH2jR_fyysKVrucFq4bKHiL84P-_Ud3EDzY2jcKuCzZtzJ7OUrLmhbUYMR0C-A1LAQr/s320/International_Artist.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 245px; height: 320px;" /></a> <br /><br />You can virtually browse a few pages of International Artist on their <a href="http://www.international-artist.com/iam/current.aspx">offical website</a>.<br />Previously on GurneyJourney: <a href="http://www.international-artist.com/iam/current.aspx">Eyetracking. </a><br /><a href="https://www.international-artist.com/subscribe.aspx?mag=IA">Subscription info for IA.</a>

Eyetracking in International Artist

The new International Artist magazine has a six page feature on the research on eyetracking and composition that I did with the help of Gr...

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Fire from the Eyes

We take for granted that our experience of vision results from the interaction of light with objects. It’s obvious, isn’t it? Light shines on objects, bounces off them, and then it stimulates our eyes.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsugbhgbxZUh-GrspdDm56F-beIl42hFL7Idk3ZFbuXm3Ku8Jsu5K1tRmzYLH_f4J4VZ3r18keO6kTpZpap5fdya2DH4rcrAgMtUaj2N5FKCmxowlL1z6OkjTMTHrmzlmUStB5whGGICMa/s1600-h/reviews-apollo.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5448124892625242066" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsugbhgbxZUh-GrspdDm56F-beIl42hFL7Idk3ZFbuXm3Ku8Jsu5K1tRmzYLH_f4J4VZ3r18keO6kTpZpap5fdya2DH4rcrAgMtUaj2N5FKCmxowlL1z6OkjTMTHrmzlmUStB5whGGICMa/s320/reviews-apollo.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 300px; height: 316px;" /></a>But for thousands of years, that basic concept was not understood. People only knew was that there was some sort of connection between the eyes and the objects seen. During the time of Aristotle in the fourth century BC, one school of thought held that the eyes emitted a visual fire that traveled to the object and somehow massaged it. Others believed that objects gave off a substance that flew toward the eye. <br /><br />These notions persisted until the time of Leonardo, who objected to the idea of fire from the eyes. He said there wouldn’t be time, after opening the eyes, for the fire to leave the eyes and travel all the way to a distant object and return. Others reasoned that if the objects gave off a flaming substance, why can’t we see at night?<br /><br />The breakthrough came from an Arab physicist Alhazen around 1000 AD, who noticed that light traveled into the eye and caused it pain. He also noticed that we experience afterimages after looking at bright light. Light—not just our eyes, and not the objects themselves—was the agent of vision.<br /><br />What I wonder as I reflect on these ideas is what was the ancient conception of light? It's mentioned often in the Hebrew bible, of course. Surely the ancients were sensitive of the action of light around them. How they regard it differently if they didn't understand its role in vision? <br />------<br />Based on material from <a href="http://www.amazon.com/Vision-Art-Margaret-S-Livingstone/dp/0810995549/ref=sr_1_1?ie=UTF8&s=books&qid=1268490496&sr=1-1">Vision and Art: The Biology of Seeing,</a> by Margaret Livingstone.<br />Image from <a href="http://discovermagazine.com/2005/nov/reviews">Discover.</a>

Fire from the Eyes

We take for granted that our experience of vision results from the interaction of light with objects. It’s obvious, isn’t it? Light shines o...

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The Two-Streams Hypothesis

In the last two decades, new scanning technology has given us a better idea of what is happening in the brain as we process visual information. <br /><br />One of the discoveries that has come out of these new data is the realization that that visual processing divides into two streams, which end up in very different parts of the brain.<br /><br />According to Dr. Margaret Stratford Livingston, Professor of neurobiology at Harvard University, the visual brain processes tonal information separately from color information.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7VpwdUsUIMk0BYi5JaZ9oyVxf3rSiX71az0jLwF2dRJTNPjLsLwIBJ7vxCeVTjlMy2I7zFTKkewPm9eLpiEpASAaBm2kIkIeZMDPeWRcJelzaqozKpteBoV1dTOdQJvxY2BV-7lT0mIrW/s1600-h/Gurney_colour_demo.jpg" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5437023564186877586" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7VpwdUsUIMk0BYi5JaZ9oyVxf3rSiX71az0jLwF2dRJTNPjLsLwIBJ7vxCeVTjlMy2I7zFTKkewPm9eLpiEpASAaBm2kIkIeZMDPeWRcJelzaqozKpteBoV1dTOdQJvxY2BV-7lT0mIrW/s400/Gurney_colour_demo.jpg" style="cursor: pointer; display: block; height: 252px; margin: 0px auto 10px; text-align: center; width: 400px;" /></a> (Addendum: I changed the image thanks to a different way of processing them--Thanks, Nick! The image on the left has only luminance, but the one on the right has color information with luminance removed.)<br /><br />The two streams originate in the retina, which begins some low-level processing. The information pathways route back to the optical cortex at the back of the brain. Although there is some crossover and interaction, the two streams are largely kept separate, from the level of the retina all the way to the higher-level vision centers of the brain.<br /><br />The area of the brain that interprets tone is several inches away from the area that interprets color, making the experience of tone and color distinct physiological experiences, as distinct as sight and hearing.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2D9OaKgKng52jSi-q-O3wwNHe5fOlY04X1BcG1Eb7yN_18nK8f8_xq7Ddy4NdcWoQYwDmmi3xt7h6PggDD_7ebIMhnAM2k5CRDYv9J0DQ5QABBESeGlDRkoz-8XZs8vYaUOW-0vYWqXaa/s1600-h/300px-Ventral-dorsal_streams.svg.png" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5436929485481162898" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2D9OaKgKng52jSi-q-O3wwNHe5fOlY04X1BcG1Eb7yN_18nK8f8_xq7Ddy4NdcWoQYwDmmi3xt7h6PggDD_7ebIMhnAM2k5CRDYv9J0DQ5QABBESeGlDRkoz-8XZs8vYaUOW-0vYWqXaa/s320/300px-Ventral-dorsal_streams.svg.png" style="cursor: pointer; display: block; height: 214px; margin: 0px auto 10px; text-align: center; width: 300px;" /></a><br /><br />The color stream (in blue), is also called the ventral stream or the “what” stream. It is more concerned with recognizing, identifying, and responding to objects. Color processing through the ventral stream is a capacity that is shared only by higher primates, not the bulk of other mammals.<br /><br />I asked Dr. Livingstone if she would describe more differences between the "where" and "what" streams? In particular, is one stream more associated with emotional response or higher cognitive function?<br /><br />“I don't know about emotions," she said, "but the dorsal (what) stream is certainly more associated with higher, conscious functions and awareness.” (Addendum: I believe Dr. Livingstone misspoke here, and meant the <span style="font-style: italic;">ventral</span> stream.)<br /><br />The difference between these two streams may explain why classically-trained artists use a strategy of planning the tonal organization of their compositions separately from the color scheme.<br /><a href="http://www.apa.org/monitor/2010/02/painters.aspx"><br />"The Artist at the Easel” by Sadie Dingfelder, February 2010 Monitor magazine of the American Psychological Association. </a><br /><br /><a href="http://en.wikipedia.org/wiki/Two_Streams_hypothesis">Two-Streams Hypothesis on Wikipedia</a>

The Two-Streams Hypothesis

In the last two decades, new scanning technology has given us a better idea of what is happening in the brain as we process visual informati...

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