abstract  background: the brain response to temporal frequencies (tf) has been already reported, but with no study reported for different tf with respect to various spatial frequencies (sf).  materials and methods: fmri was performed by 1.5t ge-system in 14 volunteers during checkerboard, with tfs of 4, 6, 8 and 10hz in low and high sfs of 0.5 and 8cpd.  results: average percentage bold signal ...

How does the human visual system detect and interpret human actions? Traditional models of the visual system suggest that the same set of visual processes is used by all observers to analyze all classes of visual images. This theoretical framework predicts that observers, whether paralyzed or athletic, analyze and perceive objects and actions similarly. Embodied theories of perception assert th...

The computer vision research aims at a better understanding of the human visual system and building artificial visual systems. Vision researchers in psychology and physiology have explored biological visual systems including the human vision, and obtained much knowledge on nature and architecture of their visual information processing. For example, some of previous results in experimental psych...

|Image halftoning converts a high-resolution image to a low-resolution image, e.g. a 24-bit color image to a three-bit color image, for printing and display. Vector error di usion captures correlation among color planes by using an error lter with matrix-valued coe cients. In optimizing vector error lters, Damera-Venkata and Evans transform the error image into an opponent color space where Euc...