Color blindness simulating plugin?

[Ladislaus]

:?:

I was wondering if one of the plugin gurus would be able to create a plugin for Paint.NET that could transform an image in order to simulate some of the more common forms of color blindness (deuteranope, protanope, and tritanope). Such a plugin would be very helpful when designing garphical content, in order to test images for 'color blind friendliness'.

I found an excellent website that deals with color blindness which also allows images/websites to be tested (additionally, the site even has a simulation plugin in the downloads section, but it is for Adobe Photoshop):

http://www.vischeck.com

To see what three of the more common forms of color blindness look like, upload an image at:

http://www.vischeck.com/vischeck/vischeckImage.php

Thank you.

[thehamster]

As I looked at the site they all ready made an algorithm. There is also a photoshop plug-in http://www.vischeck.com/downloads/. At http://www.vischeck.com/daltonize/ on the bottom it says if you would like to use it for your own application's please contact them. So one of the plug-in authors would have to contact them and get it, make the UI, and publish the plug-in.

[usedHONDA]

Well if you want an effect for that type of color blind test, try the Color Balance adjustment to let you change the red, green, blue, cyan, magenta, and yellow of the image.

[Ed Harvey]

At http://www.vischeck.com/daltonize/ on the bottom it says if you would like to use it for your own application's please contact them.

What they said was to contact them if you wanted to Licence the algorithm; that is, pay them money for it!

The theory behind this is not too complex... I'll have a play around and see what I can come up with.

No promises though; I might not be able to get it to work

[oma]

http://www.stanford.edu/~ofidaner/psych ... roject.htm

bottom of that page there is a download for the code.

[Ed Harvey]

http://www.stanford.edu/~ofidaner/psych221_proj/colorblindness_project.htm

bottom of that page there is a download for the code.

Yup, their code is almost directly lifted from the algorithm in the original paper they referenced. The results are, how can I put it nicely, 'rather average'. And their Tritanope simulation is just plain-wrong

Which just goes to show that just 'cos someone goes to Stanford it doesn't mean that everything they do/write is brilliant (take note Google )

I'll try to get some examples up to show what I mean, but that will need to wait until later (got work to do).

[oma]

yes their actual conclusions

In conclusion, our simple algorithm can provide reasonably satisfactory results for the purposes of web page design.

guess they covered their putties with that blanket statment.

[derkaderka]

Hmm this would be a nice plugin if you could edharvey, my dad is color blind and it would be curious to get an approximation of what he sees.

[Ed Harvey]

OK, here's a (very rough) approximation...

These only simulate complete red or green deficiency. They do not cover the slightly more common 'anomaly' condition. You may be able to get an impression on the anomaly condition by overlaying the simulation over the original with an opacity of about 225.

Remember these are only a rough first-order approximation, this algorithm is nowhere near as sophisticated as the one used by VizCheck !!!

EdHarvey.ColorBlindness.zip

[derkaderka]

OK, here's a (very rough) approximation...

These only simulate complete red or green deficiency. They do not cover the slightly more common 'anomaly' condition. You may be able to get an impression on the anomaly condition by overlaying the simulation over the original with an opacity of about 225.

Remember these are only a rough first-order approximation, this algorithm is nowhere near as sophisticated as the one used by VizCheck !!!

Thank you edharvey I'll be checking this out tonight, feedback soon!

[Toli]

I could try doing that...

I have to look more closely on that website.

Good suggestion.

[taboo]

Very interesting. I happen to be colorblind. My deficiency relates to the interpretation of the long/mid wavelengths in the spectrum.

1. I spent some time reading and playing around with the images provided at Vischeck: Daltonize. I left the math-work alone; however, I found their work with the pre- and post-Daltonized images of the fruit vendor disappointing. I began to wonder to what degree a person with "normal" color vision noticed a significant change - whether the spectrum-contrast in image-4 (attempted colorblind simulation, post-Daltonizing) seemed in any way enhanced from the spectrum contrast in image-2 (attempted colorblind simulation, pre-Daltonizing). For me, the only difference was that image-4 looked rather muddy. And I wasn't able to distinguish the various, suggested fruit-types in either image-2 or image-4.

2. Then I bumped over to the Stanford Project Write-Up. The write-up was wonderful, and the visible spectrum comparisons were fascinating.

3. A while ago, while maintaining a weblog, I posted an article related to color blindness and the different ways people see the world. I had posted various colorblind test examples, so I took those images, opened them in Paint, and manipulated them using Curves + --> Advanced by setting the input to Hue and output to Value/Brightness. I was then able to see each and every embedded image within the tests.

4. Finally, I downloaded EdHarvey's cool simulator. After opening an image in Paint and duplicating it twice - for a total of three layers - I titled the background layer "norm" and left it alone; I titled the middle layer "protanopic" and, you guessed it, used your effect to simulate a red-deficiency spectrum; and, lastly, I titled the top layer "deuteranopic" and, you guessed it again (nice work guessers, you're two-for-two, I'm unspeakably proud of you all), simulated a green-deficiency spectrum.

I had always known that I was colorblind, that L-M wavelengths were my interpretive deficiency, that I have trouble seeing certain reds and greens. But it seems that, while I do have trouble interpreting certain degrees of "red," I am utterly inept at distinguishing any degree of "green" at all. I must have tweaked about 100 images in the last two hours, discovering that I could hardly tell any difference between these original images and the simulated deuteranopic images.

Basically, I'm now thinking that I can't see the color green whatsoever. Wow. I'm also looking out my window and feeling very thankful that snow is white, and sky is blue.

[Ed Harvey]

I had always known that I was colorblind, that L-M wavelengths were my interpretive deficiency, that I have trouble seeing certain reds and greens.

You have a lot of company. L-M discrimination difficulty is quite common...

But it seems that, while I do have trouble interpreting certain degrees of "red," I am utterly inept at distinguishing any degree of "green" at all. I must have tweaked about 100 images in the last two hours, discovering that I could hardly tell any difference between these original images and the simulated deuteranopic images.

Basically, I'm now thinking that I can't see the color green whatsoever. Wow. I'm also looking out my window and feeling very thankful that snow is white, and sky is blue.

I cannot stress enough that these are very rough approximations!

I wouldn't put too much faith in them, especially for 'diagnostic' purposes... but I'm glad you had fun with them

[taboo]

You have a lot of company. L-M discrimination difficulty is quite common...

True . . . although, I read somewhere about a more common "difficulty" that resembles L-M interpretive deficiency. If my memory serves me, which it probably does not, the common difficulty comes from what are believed to be lazy receptors - and with a little work, an individual can somewhat improve the degree to which he interprets L-M wavelengths.

I cannot stress enough that these are very rough approximations!

I wouldn't put too much faith in them, especially for 'diagnostic' purposes...

I understand. Since yesterday, I followed up my post with a little corroborative research, which produced similar results. Rough approximations or no, your plugin seems to be a pretty accurate indicator of which wavelengths are less visible to someone with L-M color blindness.

I can't think of any way to determine exactly how accurately your plugin reproduces an L-M deficient's visible spectrum; but I wouldn't sell the farm to purchase stock in the Vischeck: Daltonize system, either.

Thanks again, Ed.

* By the way, during my obsessively compulsive researching, I found that, typically, the word "colorblind" is just that: a single word without a hyphen; however, "color blindness" is supposed to be two words. Weird. But not weirder than I am. Blah.

PS. Ed Harvey, I love your signature.