ii-pix/convert.py
kris 5cab854269 Fit palettes from overlapping line ranges, and map line to palette
when dithering with two limitations:

- cannot choose the same palette as the previous line (this avoids banding)
- must be within +/- 1 of the "base" palette for the line number

This gives pretty good results!
2021-11-11 16:10:03 +00:00

229 lines
8.9 KiB
Python

"""Image converter to Apple II Double Hi-Res format."""
import argparse
import array
import os.path
import time
import collections
import random
import colour
from PIL import Image
import numpy as np
from sklearn.cluster import KMeans
import dither as dither_pyx
import dither_pattern
import image as image_py
import palette as palette_py
import screen as screen_py
# TODO:
# - support LR/DLR
# - support HGR
def cluster_palette(image: Image):
line_to_palette = {}
#shuffle_lines = liprint(st(range(200))
#random.shuffle(shuffle_lines)
#for idx, line in enumerate(shuffle_lines):
# line_to_palette[line] = idx % 16
# for line in range(200):
# if line % 3 == 0:
# line_to_palette[line] = int(line / (200 / 16))
# elif line % 3 == 1:
# line_to_palette[line] = np.clip(int(line / (200 / 16)) + 1, 0, 15)
# else:
# line_to_palette[line] = np.clip(int(line / (200 / 16)) + 2, 0, 15)
for line in range(200):
if line % 3 == 0:
line_to_palette[line] = int(line / (200 / 16))
elif line % 3 == 1:
line_to_palette[line] = np.clip(int(line / (200 / 16)) + 1, 0, 15)
else:
line_to_palette[line] = np.clip(int(line / (200 / 16)) + 2, 0, 15)
colours_rgb = np.asarray(image).reshape((-1, 3))
with colour.utilities.suppress_warnings(colour_usage_warnings=True):
colours_cam = colour.convert(colours_rgb, "RGB",
"CAM16UCS").astype(np.float32)
palettes_rgb = {}
palettes_cam = {}
for palette_idx in range(16):
p_lower = max(palette_idx-2, 0)
p_upper = min(palette_idx+2, 16)
palette_pixels = colours_cam[
int(p_lower * (200/16)) * 320:int(p_upper * (
200/16)) * 320, :]
# kmeans = KMeans(n_clusters=16, max_iter=10000)
# kmeans.fit_predict(palette_pixels)
# palettes_cam[palette_idx] = kmeans.cluster_centers_
fixed_centroids = None
# print(np.array(line_colours), fixed_centroids)
palettes_cam[palette_idx] = dither_pyx.k_means_with_fixed_centroids(
16, palette_pixels, fixed_centroids=fixed_centroids, tolerance=1e-6)
# palette_colours = collections.defaultdict(list)
# for line in range(200):
# palette = line_to_palette[line]
# palette_colours[palette].extend(
# colours_cam[line * 320:(line + 1) * 320])
# For each line grouping, find big palette entries with minimal total
# distance
# palette_cam = None
# for palette_idx in range(16):
# line_colours = palette_colours[palette_idx]
# #if palette_idx < 15:
# # line_colours += palette_colours[palette_idx + 1]
# # if palette_idx < 14:
# # line_colours += palette_colours[palette_idx + 2]
# # if palette_idx > 0:
# # fixed_centroids = palette_cam[:8, :]
# # else:
# fixed_centroids = None
# # print(np.array(line_colours), fixed_centroids)
# palette_cam = dither_pyx.k_means_with_fixed_centroids(16, np.array(
# line_colours), fixed_centroids=fixed_centroids, tolerance=1e-6)
#kmeans = KMeans(n_clusters=16, max_iter=10000)
#kmeans.fit_predict(line_colours)
#palette_cam = kmeans.cluster_centers_
with colour.utilities.suppress_warnings(colour_usage_warnings=True):
palette_rgb = colour.convert(palettes_cam[palette_idx], "CAM16UCS", "RGB")
# SHR colour palette only uses 4-bit values
palette_rgb = np.round(palette_rgb * 15) / 15
palettes_rgb[palette_idx] = palette_rgb.astype(np.float32)
# print(palettes_rgb)
# For each line, pick the palette with lowest total distance
# best_palette = 15
# for line in range(200):
# line_pixels = colours_cam[line*320:(line+1)*320]
# best_palette = dither_pyx.best_palette_for_line(
# line_pixels, palettes_cam, best_palette)
# line_to_palette[line] = best_palette
# print(line, line_to_palette[line])
return palettes_cam, palettes_rgb, line_to_palette
def main():
parser = argparse.ArgumentParser()
parser.add_argument("input", type=str, help="Input image file to process.")
parser.add_argument("output", type=str, help="Output file for converted "
"Apple II image.")
parser.add_argument(
"--lookahead", type=int, default=8,
help=("How many pixels to look ahead to compensate for NTSC colour "
"artifacts (default: 8)"))
parser.add_argument(
'--dither', type=str, choices=list(dither_pattern.PATTERNS.keys()),
default=dither_pattern.DEFAULT_PATTERN,
help="Error distribution pattern to apply when dithering (default: "
+ dither_pattern.DEFAULT_PATTERN + ")")
parser.add_argument(
'--show-input', action=argparse.BooleanOptionalAction, default=False,
help="Whether to show the input image before conversion.")
parser.add_argument(
'--show-output', action=argparse.BooleanOptionalAction, default=True,
help="Whether to show the output image after conversion.")
parser.add_argument(
'--palette', type=str, choices=list(set(palette_py.PALETTES.keys())),
default=palette_py.DEFAULT_PALETTE,
help='RGB colour palette to dither to. "ntsc" blends colours over 8 '
'pixels and gives better image quality on targets that '
'use/emulate NTSC, but can be substantially slower. Other '
'palettes determine colours based on 4 pixel sequences '
'(default: ' + palette_py.DEFAULT_PALETTE + ")")
parser.add_argument(
'--show-palette', type=str, choices=list(palette_py.PALETTES.keys()),
help="RGB colour palette to use when --show_output (default: "
"value of --palette)")
parser.add_argument(
'--verbose', action=argparse.BooleanOptionalAction,
default=False, help="Show progress during conversion")
parser.add_argument(
'--gamma_correct', type=float, default=2.4,
help='Gamma-correct image by this value (default: 2.4)'
)
args = parser.parse_args()
if args.lookahead < 1:
parser.error('--lookahead must be at least 1')
# palette = palette_py.PALETTES[args.palette]()
screen = screen_py.SHR320Screen()
# Conversion matrix from RGB to CAM16UCS colour values. Indexed by
# 24-bit RGB value
rgb_to_cam16 = np.load("data/rgb_to_cam16ucs.npy")
# Open and resize source image
image = image_py.open(args.input)
if args.show_input:
image_py.resize(image, screen.X_RES, screen.Y_RES,
srgb_output=False).show()
rgb = np.array(
image_py.resize(image, screen.X_RES, screen.Y_RES,
gamma=args.gamma_correct, srgb_output=True)).astype(
np.float32) / 255
palettes_cam, palettes_rgb, line_to_palette = cluster_palette(rgb)
# print(palette_rgb)
# screen.set_palette(0, (image_py.linear_to_srgb_array(palette_rgb) *
# 15).astype(np.uint8))
for i, p in palettes_rgb.items():
screen.set_palette(i, (np.round(p * 15)).astype(np.uint8))
output_4bit, line_to_palette = dither_pyx.dither_shr(
rgb, palettes_cam, palettes_rgb, rgb_to_cam16)
screen.set_pixels(output_4bit)
output_rgb = np.zeros((200, 320, 3), dtype=np.uint8)
for i in range(200):
screen.line_palette[i] = line_to_palette[i]
output_rgb[i, :, :] = (
palettes_rgb[line_to_palette[i]][
output_4bit[i, :]] * 255).astype(np.uint8)
output_srgb = image_py.linear_to_srgb(output_rgb).astype(np.uint8)
# dither = dither_pattern.PATTERNS[args.dither]()
# bitmap = dither_pyx.dither_image(
# screen, rgb, dither, args.lookahead, args.verbose, rgb_to_cam16)
# Show output image by rendering in target palette
# output_palette_name = args.show_palette or args.palette
# output_palette = palette_py.PALETTES[output_palette_name]()
# output_screen = screen_py.DHGRScreen(output_palette)
# if output_palette_name == "ntsc":
# output_srgb = output_screen.bitmap_to_image_ntsc(bitmap)
# else:
# output_srgb = image_py.linear_to_srgb(
# output_screen.bitmap_to_image_rgb(bitmap)).astype(np.uint8)
out_image = image_py.resize(
Image.fromarray(output_srgb), screen.X_RES, screen.Y_RES,
srgb_output=False) # XXX true
if args.show_output:
out_image.show()
# Save Double hi-res image
outfile = os.path.join(os.path.splitext(args.output)[0] + "-preview.png")
out_image.save(outfile, "PNG")
screen.pack()
# with open(args.output, "wb") as f:
# f.write(bytes(screen.aux))
# f.write(bytes(screen.main))
with open(args.output, "wb") as f:
f.write(bytes(screen.memory))
if __name__ == "__main__":
main()