A Physiologically-Based Simulation Model of Color Appearance for Red-Green Color Vision Deficiency

Various simulation methods of color appearance for dichromats or anomalous trichromats have been proposed over the years. To further improve the performance of the simulation model and extend the application range to both dichromats and anomalous trichromats, we have proposed a simulation model of cone fundamentals specifically designed for individuals with red–green type color vision deficiency (CVD) based on the CIE 2006 physiological observer model. By utilizing the simulated cone fundamentals, it becomes possible to predict the color appearance of real scenes and digital images for CVD. The fundamental premise of the new model is rooted in the hypothesis that CVD arises from a shift in the peak wavelength of the photopigment absorption spectrum of the L- or M-cone. Instead of simply maintaining the waveform without alteration as observed in prior studies, we altered waveforms of the absorption spectra of anomalous L-/M-cone photopigments when adjusting their peak wavelengths. Regarding different shapes in the absorption spectrum between the L- and M-cones, the absorption spectrum of the anomalous L-/M-cone was obtained by combining the peak wavenumber shift and linear interpolation of spectral quantal absorption curves between L- and M-photopigments in the wavenumber domain. The performance of the proposed model was substantiated through experimental validation by the pseudoisochromatic plates and Farnsworth Munsell 100 Hue test (FM-100). The findings revealed a high level of consistency between the model prediction and the actual perception reported by individuals with CVD.