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"erase" pixels (Read 442 times)
cbernett
"erase" pixels
Oct 19th, 2008, 5:28am  
hi all.

i'm needing to slowly erode pixels from a layered stack of images and am wondering about suggested best practices. i've been tinkering with loadPixels/updatePixels, as well as the related get and set functions. I'm able to change the color of a pixel, but not simply adjust the transparency of it (which would be ideal to achieve an eroding effect).

Any advice/input would be really helpful. Thanks!
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David Wicks
Re: "erase" pixels
Reply #1 - Oct 19th, 2008, 11:06am  
You can set the value of the pixel to its original color minus some amount of alpha. Processing makes it easy to find this value with the color function. The lerpColor() function allows you to easily transition between any two color values.

Code:

float amt = 0.5;
int colorWithZeroAlpha = initialColor - color(0,0,0,255);
int newColor = lerpColor( initialColor, colorWithZeroAlpha, amt );


http://processing.org/reference/lerpColor_.html
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-David&&sansumbrella
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