Sensation of Realness From High-Resolution Images of Real Objects

We performed subjective assessments to quantify the sensation of realness for images at various angular resolutions and that of their real-object counterparts using a paired-comparison procedure. Both the images and real objects were viewed through a synopter, which removed horizontal disparity and presented the same images to both eyes. The size, perspective, luminance, and chromaticity of the images were reproduced to be identical to those of the real objects. Eighty-two observers with normal vision were asked to choose the viewed image that appeared most similar to the real object for each pair of images. The results indicated that the realness of images increased steadily as the image resolution increased up to around 60 cycles per degree, whereafter it gradually approached that of the real objects.