In order to emphasize the failures, highlight the places a page fails. This will probably necessitate filtering out pixel differences where the ratio is 0, like for solid background colors.
See comment on http://accessibility.oit.ncsu.edu/blog/2013/10/29/color-contrast-analyzer-for-chrome-text-in-images-gradients-pdfs-and-more/#comment-253508
In order to emphasize the failures, highlight the places a page fails. This will probably necessitate filtering out pixel differences where the ratio is 0, like for solid background colors.
See comment on http://accessibility.oit.ncsu.edu/blog/2013/10/29/color-contrast-analyzer-for-chrome-text-in-images-gradients-pdfs-and-more/#comment-253508