Three sets of color tone stimuli were created for three hues, red, green and blue, by varying just two parameters, saturation and value. Two methods were employed to study how native speakers of Japanese use adjectives to describe differences in their perceptions of color tones. A preliminary elicitation employed the methods of selection description, in which Japanese adjectives meaning pale, bright, vivid, strong, dull and dark constituted a high proportion of responses for 56 Japanese native speakers. These adjectives were employed in a triadic comparison method for the same stimuli, and the adjectives were used in a consistent manner for all three hues. Of particular interest were two pairs of adjective contrasts, first, vivid vs. dull, described variation along the axis connecting the tone at both highest saturation and highest value with the tone at both lower saturation and lower value. The second adjective contrast, bright vs. strong, was practically orthogonal to the first. To further document the consensual use of these pairs of adjectives in describing variation of color tone, two additional experiments were executed to determine the boundary color tones at which adjective labels switch from bright to strong and from vivid to dull.
A tone mapping algorithm for displaying high contrast scenes
was designed on the basis of the results of experimental tests using human subjects. Systematic perceptual evaluation of several existing tone mapping techniques revealed that the most "natural" appearance was determined by the presence in the output image of detailed scenery features often made visible by limiting contrast and by properly reproducing brightness. Taking these results into account, we developed a system to produce images close to the ideal preference point for high dynamic range input image data. Of the algorithms that we tested, only the Retinex algorithm was capable of retrieving detailed scene features hidden in high luminance areas
while still preserving a good contrast level. This paper presents changes made to Retinex algorithm for processing high dynamic range images, and a further integration of the Retinex with specialized tone mapping algorithms that enables the production of images that appear as similar as possible to the viewer's perception of actual scenes.
With the advent of mass distribution of consumer VR games comes an imperative to set health and safety standards for the hardware and software used to deliver stereographic content. This is particularly important for game developers who intend to present this stereographic content via head-mounted display (HMD). The visual discomfort that is commonly reported by the user of HMD-based VR games presumably could be kept to a minimum if game developers were provided with standards for the display of stereographic imagery. In this paper, we draw upon both results of research in binocular vision and practical methods from clinical optometry to develop some technical guidelines for programming stereographic games that have the end user's comfort and safety in mind. This paper will provide generate strategies for user- centered implementation of 3D virtual worlds, as well as pictorial examples demonstrating a natural means for rendering stereographic imagery more comfortable to view in games employing first-person perspective.