The MPEG-21 Multimedia Framework allows visually impaired users to have an improved access to visual content by enabling content adaptation techniques such as color compensation. However, one important issue is the method to create and interpret the standardized CVD descriptions when making the use of generic color vision tests. In Part I of our study to tackle the issue, we present a novel computerized hue test (CHT) to examine and quantify CVD, which allows reproducing and manipulating test colors for the purposes of computer simulation and analysis of CVD. Both objective evaluation via color difference measurement and subjective evaluation via clinical experiment showed that the CHT works well as a color vision test: it is highly correlated with the Farnsworth-Munsell 100 Hue (FM100H) test and allows for a more elaborate and correct color reproduction than the FM100H test. Copyright (C) 2008 Seungji Yang et al.

A color compensation scheme has been developed to enhance the perception of people with color vision deficiency (CVD) and for people suffering from anomalous trichromacy. It is operated within the MPEG-21 Multimedia Framework, which provides a standardized description of CVD. The basic idea behind the proposed color compensation consists of simulating the path of human color perception. As such, compensated color is realized by relying on the spectral cone sensitivities of the human eye and the spectral emission functions of the display device. For quantified color compensation, the spectral sensitivity of anomalous cones has been modeled according to the deficiency degree of the standardized CVD description. The latter is based on the error score of a computerized hue test (CHT), developed in Part I of our study. Given the anomalous cone spectra, the reduction of error score on the CHT after color compensation was measured in each deficiency degree. The quantitative relationship of color compensation with the error score is linearly regressed, based on the deficiency degree with the least error score after color compensation as well as the error score before color compensation. Copyright (C) 2008 Seungji Yang et al.