Human visual system model: Difference between revisions

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It is common to think of "taking advantage" of the HVS model to produce desired effects. Examples of taking advantage of an HVS model include colour 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 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_data_compression#Lossy_audio_compression | audio compression]], where sound frequencies inaudible to humans are bandpass 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 a1at optical illusions.

==Assumptions about the HVS==