import numpy as np def get_color_map(N=256): def bitget(byteval, idx): return ((byteval & (1 << idx)) != 0) cmap = np.zeros((N, 3), dtype=np.uint8) for i in range(N): r = g = b = 0 c = i for j in range(8): r = r | (bitget(c, 0) << 7 - j) g = g | (bitget(c, 1) << 7 - j) b = b | (bitget(c, 2) << 7 - j) c = c >> 3 cmap[i] = np.array([r, g, b]) return cmap color_map = get_color_map() def pal_color_map(): return color_map