Greetings protans, deutans, and other color abnormals! Here you'll find some simple tools I made to help colorblind people (specifically red-green colorblind people) with web images. These tools are especially useful for graphs or figures where a lot of the useful information is in the red-green color axis. For these kinds of images it's nice to be able to take all the red-green information and transform it into blue-yellow, or green-magenta information.
Here's an example of an image that some wikipedia editor who is clearly not colorblind clearly spent a lot of time on. It is meaningless to me (a protanope):
Here's the same map translated into blue-yellow contrast. With a minimum of effort, the meaningless becomes pretty keen. Huzzah! The magic of the internet:
You can generate translated maps dynamically using links like the following:
Or simply install one of these bookmarklets and activate it when you are at the URL for the image you want to transform:
Note, however, that if the site hosting your desired image is restricted access or requires cookies to be on, then none of this will work. I'm trying to fix this now, but it's kind of a pain.
There's a similar web tool available at vischeck.com, but their more complicated algorithm is less effective at revealing hidden red-green information specifically and they require you to upload an image rather than just pointing to its URL.
I'm planning to write some more sophisticated image processing tools that will rotate the color space to minimize the information content reliant on the red or green axes for example. But don't know when I will have time for that.
Here are some cool guys who advocate standardizing a green-magenta contrast system similar to what I have implemented here as a dynamic workaround. I hacked my logo from their logo. And by hacked I mean stole; I don't think they'll mind; who knows, their homepage is in Japanese!
I also recommend you check out the blog ColBlindor, run by colorblind blogger Daniel Flueck
