Testing custom PNG writer for PIL that allows non 256 size palettes

test_our_png_writer.py

import PIL.Image, our_png_save

im = PIL.Image.new('RGB', (256, 256))
p = im.load()
for y in range(256):
	for x in range(256):
		p[x,y] = (x, y, (x * y) >> 8)

colors = set()
for y in range(256):
	for x in range(256):
		colors.add(p[x, y])
print(len(colors))	#I have 65536 colors


def save_to_png_with_limited_palette(im, filename, count=256):
	out = im.convert('P', palette=PIL.Image.ADAPTIVE, colors=count)
	out.palette.palette = out.palette.palette[:count*3]	#Truncate palette
	out.save(filename)


save_to_png_with_limited_palette(im, 't1.png', 63)

test = PIL.Image.open('t1.png')
print(len(test.palette.palette) // 3)	#I have 63 colors