ref: 52bcd78290ecc185df83e524044e34bfb3e7b58b
parent: ee36bd9342cce0e728431428b91d6f2074db2f21
author: Rangi <remy.oukaour+rangi42@gmail.com>
date: Mon Mar 15 14:21:33 EDT 2021
palfix.py outputs 2-bit grayscale if possible
--- a/tools/palfix.py
+++ b/tools/palfix.py
@@ -12,7 +12,7 @@
def rgb5_to_rgb8(c):
r, g, b = c
- return ((r * 8) | (r // 4), (g * 8) | (g // 4), (b * 8) | (b // 4))
+ return (r * 8 + r // 4, g * 8 + g // 4, b * 8 + b // 4)
def invert(c):
r, g, b = c
@@ -20,7 +20,7 @@
def luminance(c):
r, g, b = c
- return (0.299 * r**2 + 0.587 * g**2 + 0.114 * b**2)**0.5
+ return 0.299 * r**2 + 0.587 * g**2 + 0.114 * b**2
def rgb5_pixels(row):
for x in range(0, len(row), 4):
@@ -33,7 +33,7 @@
b_and_w = {(0, 0, 0), (31, 31, 31)}
colors = set(c for row in data for c in rgb5_pixels(row)) - b_and_w
if not colors:
- colors = {(20, 20, 20), (10, 10, 10)}
+ colors = {(21, 21, 21), (10, 10, 10)}
elif len(colors) == 1:
c = colors.pop()
colors = {c, invert(c)}
@@ -42,8 +42,12 @@
palette = tuple(sorted(colors | b_and_w, key=luminance, reverse=True))
assert len(palette) == 4
data = [list(map(palette.index, rgb5_pixels(row))) for row in data]
- palette = tuple(map(rgb5_to_rgb8, palette))
- writer = png.Writer(width, height, palette=palette, compression=9)
+ if palette == ((31, 31, 31), (21, 21, 21), (10, 10, 10), (0, 0, 0)):
+ data = [[3 - c for c in row] for row in data]
+ writer = png.Writer(width, height, greyscale=True, bitdepth=2, compression=9)
+ else:
+ palette = tuple(map(rgb5_to_rgb8, palette))
+ writer = png.Writer(width, height, palette=palette, bitdepth=8, compression=9)
with open(filename, 'wb') as file:
writer.write(file, data)
return True