I'm looking for a way to load up an existing png image, and do a pixel by pixel manipulation of the values. Ideally, something like
image = Image.open('my.png')
image = image.map_each_rgb do |r, g, b|
[r-12, g+2, b+30]
end
image.save('my.png')
I've looked into rmagick, but couldn't find a way to achieve this.
Are there any alternatives that would allow such image editing?
How about RMagick's each_pixel
method?
http://studio.imagemagick.org/RMagick/doc/image2.html#each_pixel
img.each_pixel {|pixel, c, r| block }