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Index › Programming Questions & Help › Syntax Questions › desaturating an image

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desaturating an image (Read 680 times)

philth

desaturating an image
Jul 28^th, 2009, 9:42am

hi all,
i have a color image which i would like to fade to gray and back to color. my first thought was to use the tint() function in hsb color mode, but any transformation where the saturation value is 0 has no impact. then i found PImage.filter(GRAY) but this cannot be animated (and it is awfully slow).

i would like to avoid using two seperate images and fade them into each other.

any suggestions?

blindfish

Re: desaturating an image
Reply #1 - Jul 28^th, 2009, 10:40am

I've not tried this, but from what I've read in the past it sounds like you might want to use bitwise operators on the pixels[] array. In fact a search on "bitwise operators desaturate" turned up this. It's PHP - but I'm sure the principles remain the same - and it doesn't animate; but I guess you could calculate the greyscale target value and then iterate the colour values towards it somehow...

Where is the what if the what is in why?

Cedric YaBB Moderator Offline Posts: 1838	Re: desaturating an image Reply #2 - Jul 28^th, 2009, 11:02am maybe you find something in here : http://www.davebollinger.com/works/imageadjuster/
	twitter.com/CedricKiefer

philth

Re: desaturating an image
Reply #3 - Jul 31^st, 2009, 2:12pm

thanks to both of you!
the approach shown in php seams to be working, but as you said it doesn't really support animation. and the imageadjuster unfortunately doesn't seam to work with saturation.
so it probably really would be best to create two versions of the image first and then blend them into each other.
anyway, because of some hardware-issues i had to switch the whole projects over to openframeworks/c++, but i'll post it here if i come across a better solution.

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