Modeling study: Results of the analysis of hyperspectral images
MINOR, LENS
Calculated chromatic contrast changes in L/(L+M) as a percentage of 95% of the unfiltered image gamut for each dataset show that the test lens is predicted to cause very little change in L/(L+M) chromatic contrast. Results vary by scene, and each dataset is composed of different scenes, so we present all results and report the range across datasets herein. L/(L+M) chromatic contrast is predicted to change by, at most, –1.4% and +1.1%. Between 1% and 16% of pixels (for different datasets) exhibit L/(L+M) chromatic contrast reductions of more than 0.5%, and between 1% and 7% of pixels exhibit L/(L+M) chromatic contrast enhancements of more than 0.5%. Although the change is minor, between 35% and 67% of pixels exhibit L/(L+M) chromatic contrast reductions, and the average reduction is between 0.0% and 0.1% (Percentile changes in chromatic contrast for L/(L+M) (left) and S/(L+M) (right) as a percentage of the original image gamut for age = 20 years and macular pigment optical density = 0.35. The collective dataset is comprised of five sets of hyperspectral images: Four image sets were obtained from the literature: Conversely, calculated chromatic contrast changes in S/(L+M) as a percentage of 95% of the unfiltered image gamut show that the test lens is predicted to generally degrade S/(L+M) chromatic contrast. Results varied slightly by scene and dataset such that the S/(L+M) chromatic contrast for individual pixels was predicted to change by, at most, –36.9% and +5.0%. Between 82% and 92% of pixels exhibited S/(L+M) chromatic contrast reductions of more than 0.5%, and between 5% and 10% of pixels exhibited S/(L+M) chromatic contrast enhancements of more than 0.5%. Between 87% and 94% of pixels exhibited S/(L+M) chromatic contrast reductions, and the average reduction was between 3.6 and 8.2% (A single example of a hyperspectral image of a color pencil set (from the custom Specim IQ dataset) is provided to illustrate the impact of the filter (Hyperspectral image of a colored pencil set and assessments of the impact of the filter. (Top left) Original hyperspectral image recast in RGB. (Top right) Filtered hyperspectral image recast in RGB. (Middle left) Change in L/(L+M) as a percentage of 95% of the original image gamut. (Middle right) Change in S/(L+M) as a percentage of 95% of the original image gamut. (Bottom left) Change in L+M as a percentage of 95% of the original image gamut. (Bottom right) Scatterplot of the chromatic contrast of pixels in the image shown with (blue) and without (red) the filter.