Re: [pygame] Trouble with PixelArray

[Russell Jones <russell.jones@xxxxxxxxx>]

This may or may not be relevant, but notice that 41+86=128.

[bin(x) for x in [0, 41, 86, 127]]

[0b0, 0b101001, 0b1010110, 0b1111111]

Russell

On 19 February 2012 17:00, Erik Grahn J. <erikgj@xxxxxxxxx> wrote:

Hey all,

I'm writing something where I load 4-colour indexed PNG images (8x8 tiles) with a simple greyscale palette (four entries, in order: black, dark grey, light grey, white) off disk. I then intend to recolour these in different ways by replacing the palette indices using PixelArray.replace, but I'm kind of getting stuck because I'm not getting the palette values I want from the file.

In the 8-bit PNG, my four greyscale colours are unquestionably palette indices 0-3 (I have verified this with a hex editor even, they are the first four values in the PLTE chunk) but when I turn my surface into a PixelArray and print it, it looks like this:

   ÂPixelArray(
    Â[0, 0, 86, 127, 127, 0, 0, 0]
    Â[0, 86, 127, 86, 86, 86, 0, 0]
    Â[86, 127, 86, 86, 41, 86, 86, 0]
    Â[86, 127, 86, 86, 41, 86, 86, 0]
    Â[86, 127, 86, 86, 41, 86, 86, 0]
    Â[86, 127, 86, 41, 41, 86, 86, 0]
    Â[0, 86, 127, 86, 86, 86, 0, 0]
    Â[0, 0, 86, 86, 86, 0, 0, 0]
   Â)

So instead of the values I want (0, 1, 2, 3), I'm getting 0, 41, 86 and 127. I have no idea where it gets these numbers from. Possibly a conversion to some internal default palette somewhere? I have tried calling set_palette on the surface to no avail -- same results.

Any help would be super appreciated.


--
Erik Grahn J. <erikgj@xxxxxxxxx>