A human visual system model (HVS model) is used by image processing, video processing and computer vision experts to deal with biological and psychological processes that are not yet fully understood. Such a model is used to simplify the behaviours of what is a very complex system. As our knowledge of the true visual system improves, the model is updated.
Psychovisual study is the study of the psychology of vision.
The human visual system model can be used to produce desired effects in perception and vision. Examples of using an HVS model include color television, lossy compression, and Cathode-ray tube (CRT) television.
Originally it was thought that colour television required too high a bandwidth for the then available technology. Then it was noticed that the colour resolution of the HVS was much lower than the brightness resolution; this allowed colour to be squeezed into the signal by chroma subsampling.
Another example is lossy image compression, like JPEG. Our HVS model says that we cannot see high frequency detail so in JPEG we can quantise these components without a perceptible loss of quality. Similar concepts are applied in audio compression, where sound frequencies inaudible to humans are bandstop filtered.
Several HVS features are derived from evolution, when we needed to defend ourselves or hunt for food. We often see demonstrations of HVS features when we are looking at optical illusions.
human, visual, system, model, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jsto. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Human visual system model news newspapers books scholar JSTOR October 2008 Learn how and when to remove this template message This article s tone or style may not reflect the encyclopedic tone used on Wikipedia See Wikipedia s guide to writing better articles for suggestions September 2022 Learn how and when to remove this template message A human visual system model HVS model is used by image processing video processing and computer vision experts to deal with biological and psychological processes that are not yet fully understood Such a model is used to simplify the behaviours of what is a very complex system As our knowledge of the true visual system improves the model is updated Psychovisual study is the study of the psychology of vision The human visual system model can be used to produce desired effects in perception and vision Examples of using an HVS model include color television lossy compression and Cathode ray tube CRT television Originally it was thought that colour television required too high a bandwidth for the then available technology Then it was noticed that the colour resolution of the HVS was much lower than the brightness resolution this allowed colour to be squeezed into the signal by chroma subsampling Another example is lossy image compression like JPEG Our HVS model says that we cannot see high frequency detail so in JPEG we can quantise these components without a perceptible loss of quality Similar concepts are applied in audio compression where sound frequencies inaudible to humans are bandstop filtered Several HVS features are derived from evolution when we needed to defend ourselves or hunt for food We often see demonstrations of HVS features when we are looking at optical illusions Contents 1 Block diagram of HVS 2 Assumptions about the HVS 3 Examples of taking advantage of an HVS model 4 See also 5 ReferencesBlock diagram of HVS editThis section is empty You can help by adding to it February 2018 Assumptions about the HVS editLow pass filter characteristic limited number of rods in human eye see Mach bands Lack of colour resolution fewer cones in human eye than rods Motion sensitivity More sensitive in peripheral vision Stronger than texture sensitivity e g viewing a camouflaged animal Texture stronger than disparity 3D depth resolution does not need to be so accurate Integral Face recognition babies smile at faces Depth inverted face looks normal facial features overrule depth information Upside down face with inverted mouth and eyes looks normal 1 Examples of taking advantage of an HVS model editFlicker frequency of film and television using persistence of vision to fool viewer into seeing a continuous image Interlaced television painting half images to give the impression of a higher flicker frequency Colour television chrominance at half resolution of luminance corresponding to proportions of rods and cones in eye Image compression difficult to see higher frequencies more harshly quantised Motion estimation use luminance and ignore colour Watermarking and SteganographySee also editPsychoacoustics Visual system Visual perception Depth perceptionReferences edit Margaret Thatcher Illusion Mighty Optical Illusions Retrieved from https en wikipedia org w index php title Human visual system model amp oldid 1135085416, wikipedia, wiki, book, books, library,
