As if by magic, the nice grey wall has turned into a black wall.

What image formats do you use? I see you are writing a PNG, that can be both a paletted image and a non-paletted image. What formats do you read?

(On palettes: A paletted image has a small array of colors, usually 24 bit RGB colors, and usually not more than 256 color entries. Each pixel is stored as an array index, typically one byte. A non-paletted image stores the color information directly in the pixel data, using 3 or 4 bytes per pixel.)

"Magic" color changes usually happen with paletted images, especially if the tool is too simple-minded, or when you run out of palette entries. What happens is that the palette is silently modified or the color allocation fails because the palette array is full. Try to use non-paletted images, i.e. make sure GD is in "true color" mode. Call isTrueColor() on your GD objects, should return true. Pass a true value for the optional truecolor parameter to the GD constructors. That way, paletted images are automatically upgraded to non-paletted mode (as far as I understand GD.)

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

In reply to Re^3: GD colorAllocate not changing colour by afoken
in thread GD colorAllocate not changing colour by Bod

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