Human visual system model

<h2 id="block-diagram-of-hvs">Block diagram of HVS</h2>

<h2 id="assumptions-about-the-hvs">Assumptions about the HVS</h2>
<ul><li><a href="/facts/Low-pass_filter/QFsUjw7h">Low-pass filter</a> characteristic (limited number of rods in human eye): see <a href="/facts/Mach_bands/nubDv69P">Mach bands</a></li>
<li>Lack of color resolution (fewer cones in human eye than rods)</li>
<li>Motion sensitivity
<ul><li>More sensitive in <a href="/facts/Peripheral_vision/r436lpjQ">peripheral vision</a></li>
<li>Stronger than texture sensitivity, e.g. viewing a camouflaged animal</li></ul></li>
<li>Texture stronger than disparity – 3D depth resolution does not need to be so accurate</li>
<li>Integral Face recognition (babies smile at faces)
<ul><li><a href="/facts/Hollow-face_illusion/j6DIw6aN">Depth inverted face looks normal</a> (facial features overrule depth information)
<ul><li>Upside down face with inverted mouth and eyes looks normal<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a></li></ul></li></ul></li></ul>
<h2 id="examples-of-taking-advantage-of-an-hvs-model">Examples of taking advantage of an HVS model</h2>
<ul><li><a href="/facts/Flicker_fusion_threshold/Bbt0HRrk">Flicker frequency of film and television using persistence of vision to fool viewer into seeing a continuous image</a></li>
<li><a href="/facts/Interlaced_video/YBk246TF">Interlaced television</a> painting half images to give the impression of a higher flicker frequency</li>
<li>Color television (chrominance at half resolution of luminance corresponding to proportions of rods and cones in eye)</li>
<li>Image compression (difficult to see higher frequencies more harshly quantized)</li>
<li><a href="/facts/Motion_estimation/FF2TIndo">Motion estimation</a> (use luminance and ignore color)</li>
<li><a href="/facts/Watermark/QMzKKCLt">Watermarking</a> and <a href="/facts/Steganography/RGLdKYcE">Steganography</a></li></ul>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Psychoacoustics/1GRCBbfQ">Psychoacoustics</a></li>
<li><a href="/facts/Visual_system/QVcuA27K">Visual system</a></li>
<li><a href="/facts/Visual_perception/g7Tfaq2l">Visual perception</a></li>
<li><a href="/facts/Depth_perception/R6FK2z6o">Depth perception</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Margaret Thatcher Illusion – Mighty Optical Illusions <a href="http://www.moillusions.com/2006/09/margaret-thatcher-illusion.html" target="_blank">http://www.moillusions.com/2006/09/margaret-thatcher-illusion.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
</ol>

Human visual system model open-in-new

Human visual system model