ApPlication ofdigital imaging and virtual in psychophysical studies reality techniques Takao SATO [ ITnivers ' idy ' of TolpiO * Astudy on gaze perception was described to exemplify image processing and presentation techniques that are useful f 〔, r psych 〔, physical experlmelts . We perceive an 〔 〕ther pers 〔 ml s gaze direction accurately fl ・ om straight ahead , but the perception becomes inaccurate when the person ' s head is turned . This error has been attributed to the misjudgrnellt of

more »

... e gaze itself , but the errQr cou ! d stern from anQther source , To examining such a possibility we conducted several experi − mcnts . First, we measured the accuracy of gaze −. direction estimati 〔 m for fuH − size cobr photo ・ graphs with several gaze and head − turn angLes presellted olll GRT . Results indicate that gaze perccption is accurate from Straight . ahead , but tha しasmall but systemat . ic error occurs 「 or stimtlli with a head turn. Next, we had subjects evaluate head tums for sinlilar stimuli , and found that the head turn is generally underestlmated . The results suggest that the error in estimating gaze direction is caused by underestimation of head turn . This possibility was further tested by presenting synthesized ilnages in which underestiniation ( )f hcad turns was cDmpensated by adding more head turn while keeping the eyes the same . The ermr was dralnatically decreased for these pictures . Key words : virtual reality , psychophysics, digital irnage pl ' ocessin9 , gaze L は じめ に