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[java] Darken a BufferedImage

Started by H_o_p_s Sep 18, 2005 at 12:32 PM 3 replies 2k views

Original Post

115

Sep 18, 2005 at 12:32 PM

I know that there is a way to do this, but I can't make my way through the AffineTransform to get it working... if anyone has a quick code snippet they could post it would be wonderfull. Thanks!

n0rmanfreak

Sep 18, 2005 at 2:46 PM

hi h_o_p_s

affineTransformation seems to be the wrong way as it's working only a coordinates not on color values.. i'm not sure if this can be done with the colorConvert class... a straight forward approch would be to loop through all pixels and set there rgbValue to (getRgb * alpha) where alpha is a number between 0 and 1 representing the darkening you want to achieve..

hope this helps..

i'll took a deeper look into that colorConvert...maybe i'll find something useful

good luck!

stormrunner

Sep 18, 2005 at 3:04 PM

This seems to be what you seek. FYI, that site is a great resource for such things. If you didn't want to read, here's the relevant snippet :

// Darken the image by 10%float scaleFactor = .9f; // out of 100 ... obviouslyRescaleOp op = new RescaleOp(scaleFactor, 0, null);bufferedImage = op.filter(bufferedImage, null);

Yeah, "RescaleOp" is a bit misleading, but it does what you want [grin].