Android desaturate specific color

Question

I am making some kind of image filter, and I need to desaturate (remove saturation) for a specific color. For example red. I want my image to replace all red colors with gray.
Change this image

To this

Any idea?

Will Bobo · Answer 1 · 2015-07-23T14:51:59.600

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It's say there http://developer.android.com/reference/android/graphics/ColorMatrixColorFilter.html that ColorMatrixColorFilter can be used to change saturation of pixel. But you have to play with math and ColorMatrix

Is that what you're researching ?

Edit : There is not such thing in Android standard library. Filter are written in NDK for performance issue, so you'll need to do the same for a custom filter.

Another idea without thinking of performance is : loop through all pixels and desaturate when it's "red"

edited Jul 23 '15 at 14:51

answered Jul 23 '15 at 14:17

Will Bobo

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I didn't use ColorMatrixColorFilter until now. Is there a way to remove spectre of specific colour? Like in image I have posted up. I don't want to remove only #ff0000, but all red colors. – filipst Jul 23 '15 at 14:22
I suppose red color = A color with R>0 in RGB value ? – Will Bobo Jul 23 '15 at 14:29
Yeah, but (219, 148, 36) is orange, not red. – filipst Jul 23 '15 at 14:32
Well, how do you define red ? – Will Bobo Jul 23 '15 at 14:36
Well, that is the problem. That image from above is photoshop effect. I have desaturated red color. I need same effect for android. If there is one. – filipst Jul 23 '15 at 14:38
It seems, ColorMatrixColorFilter is not your solution... I will think of something else – Will Bobo Jul 23 '15 at 14:47

score 0 · Answer 2 · answered Jul 23 '15 at 14:19

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I think you can use OR login to add a "filter" to your color RGB or ARGB

int filter = 0x00CC0000 | color;
myView.setBackgroundColor(filter);

answered Jul 23 '15 at 14:19

heloisasim

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Android desaturate specific color

2 Answers2