import argparse import bz2 import functools import os.path import pickle import time from typing import Tuple from PIL import Image import numpy as np import dither_apply # TODO: # - only lookahead for 560px # - palette class # - compare to bmp2dhr and a2bestpix def srgb_to_linear_array(a: np.ndarray, gamma=2.4) -> np.ndarray: return np.where(a <= 0.04045, a / 12.92, ((a + 0.055) / 1.055) ** gamma) def linear_to_srgb_array(a: np.ndarray, gamma=2.4) -> np.ndarray: return np.where(a <= 0.0031308, a * 12.92, 1.055 * a ** (1.0 / gamma) - 0.055) def srgb_to_linear(im: np.ndarray) -> np.ndarray: rgb_linear = srgb_to_linear_array(im / 255.0, gamma=2.4) return (np.clip(rgb_linear, 0.0, 1.0) * 255).astype(np.float32) def linear_to_srgb(im: np.ndarray) -> np.ndarray: srgb = linear_to_srgb_array(im / 255.0, gamma=2.4) return (np.clip(srgb, 0.0, 1.0) * 255).astype(np.float32) # Default bmp2dhr palette RGB = { 0: np.array((0, 0, 0)), # Black 8: np.array((148, 12, 125)), # Magenta 4: np.array((99, 77, 0)), # Brown 12: np.array((249, 86, 29)), # Orange 2: np.array((51, 111, 0)), # Dark green 10: np.array((126, 126, 125)), # Grey2 6: np.array((67, 200, 0)), # Green 14: np.array((221, 206, 23)), # Yellow 1: np.array((32, 54, 212)), # Dark blue 9: np.array((188, 55, 255)), # Violet 5: np.array((126, 126, 126)), # Grey1 13: np.array((255, 129, 236)), # Pink 3: np.array((7, 168, 225)), # Med blue 11: np.array((158, 172, 255)), # Light blue 7: np.array((93, 248, 133)), # Aqua 15: np.array((255, 255, 255)), # White } # Maps palette values to screen dots. Note that these are the same as # the binary values in reverse order. DOTS = { 0: (False, False, False, False), 1: (True, False, False, False), 2: (False, True, False, False), 3: (True, True, False, False), 4: (False, False, True, False), 5: (True, False, True, False), 6: (False, True, True, False), 7: (True, True, True, False), 8: (False, False, False, True), 9: (True, False, False, True), 10: (False, True, False, True), 11: (True, True, False, True), 12: (False, False, True, True), 13: (True, False, True, True), 14: (False, True, True, True), 15: (True, True, True, True) } DOTS_TO_4BIT = {} for k, v in DOTS.items(): DOTS_TO_4BIT[v] = k # OpenEmulator sRGB = { 0: np.array((0, 0, 0)), # Black 8: np.array((206, 0, 123)), # Magenta 4: np.array((100, 105, 0)), # Brown 12: np.array((247, 79, 0)), # Orange 2: np.array((0, 153, 0)), # Dark green # XXX RGB values are used as keys in DOTS dict, need to be unique 10: np.array((131, 132, 132)), # Grey2 6: np.array((0, 242, 0)), # Green 14: np.array((216, 220, 0)), # Yellow 1: np.array((21, 0, 248)), # Dark blue 9: np.array((235, 0, 242)), # Violet 5: np.array((140, 140, 140)), # Grey1 # XXX 13: np.array((244, 104, 240)), # Pink 3: np.array((0, 181, 248)), # Med blue 11: np.array((160, 156, 249)), # Light blue 7: np.array((21, 241, 132)), # Aqua 15: np.array((244, 247, 244)), # White } # # Virtual II (sRGB) # sRGB = { # (False, False, False, False): np.array((0, 0, 0)), # Black # (False, False, False, True): np.array((231,36,66)), # Magenta # (False, False, True, False): np.array((154,104,0)), # Brown # (False, False, True, True): np.array((255,124,0)), # Orange # (False, True, False, False): np.array((0,135,45)), # Dark green # (False, True, False, True): np.array((104,104,104)), # Grey2 XXX # (False, True, True, False): np.array((0,222,0)), # Green # (False, True, True, True): np.array((255,252,0)), # Yellow # (True, False, False, False): np.array((1,30,169)), # Dark blue # (True, False, False, True): np.array((230,73,228)), # Violet # (True, False, True, False): np.array((185,185,185)), # Grey1 XXX # (True, False, True, True): np.array((255,171,153)), # Pink # (True, True, False, False): np.array((47,69,255)), # Med blue # (True, True, False, True): np.array((120,187,255)), # Light blue # (True, True, True, False): np.array((83,250,208)), # Aqua # (True, True, True, True): np.array((255, 255, 255)), # White # } RGB = {} for k, v in sRGB.items(): RGB[k] = (np.clip(srgb_to_linear_array(v / 255), 0.0, 1.0) * 255).astype( np.uint8) class ColourDistance: @staticmethod def distance(rgb1: np.ndarray, rgb2: np.ndarray) -> np.ndarray: raise NotImplementedError class CIE2000Distance(ColourDistance): """CIE2000 delta-E distance.""" def __init__(self): self._distances = np.memmap("distances.npy", mode="r+", dtype=np.uint8, shape=(16777216, 16)) class Screen: X_RES = None Y_RES = None X_PIXEL_WIDTH = None def __init__(self): self.main = np.zeros(8192, dtype=np.uint8) self.aux = np.zeros(8192, dtype=np.uint8) @staticmethod def y_to_base_addr(y: int) -> int: """Maps y coordinate to screen memory base address.""" a = y // 64 d = y - 64 * a b = d // 8 c = d - 8 * b return 1024 * c + 128 * b + 40 * a def _image_to_bitmap(self, image: np.ndarray) -> np.ndarray: raise NotImplementedError def pack(self, image: np.ndarray): bitmap = self._image_to_bitmap(image) # The DHGR display encodes 7 pixels across interleaved 4-byte sequences # of AUX and MAIN memory, as follows: # PBBBAAAA PDDCCCCB PFEEEEDD PGGGGFFF # Aux N Main N Aux N+1 Main N+1 (N even) main_col = np.zeros( (self.Y_RES, self.X_RES * self.X_PIXEL_WIDTH // 14), dtype=np.uint8) aux_col = np.zeros( (self.Y_RES, self.X_RES * self.X_PIXEL_WIDTH // 14), dtype=np.uint8) for byte_offset in range(80): column = np.zeros(self.Y_RES, dtype=np.uint8) for bit in range(7): column |= (bitmap[:, 7 * byte_offset + bit].astype( np.uint8) << bit) if byte_offset % 2 == 0: aux_col[:, byte_offset // 2] = column else: main_col[:, (byte_offset - 1) // 2] = column for y in range(self.Y_RES): addr = self.y_to_base_addr(y) self.aux[addr:addr + 40] = aux_col[y, :] self.main[addr:addr + 40] = main_col[y, :] @staticmethod def pixel_palette_options(last_pixel, x: int): raise NotImplementedError class DHGR140Screen(Screen): """DHGR screen ignoring colour fringing, i.e. treating as 140x192x16.""" X_RES = 140 Y_RES = 192 X_PIXEL_WIDTH = 4 def _image_to_bitmap(self, image_4bit: np.ndarray) -> np.ndarray: bitmap = np.zeros( (self.Y_RES, self.X_RES * self.X_PIXEL_WIDTH), dtype=np.bool) for y in range(self.Y_RES): for x in range(self.X_RES): pixel = image_4bit[y, x].item() dots = DOTS[pixel] bitmap[y, x * self.X_PIXEL_WIDTH:( (x + 1) * self.X_PIXEL_WIDTH)] = dots return bitmap @staticmethod def pixel_palette_options(last_pixel_4bit, x: int): return np.array(list(RGB.keys())), np.array(list(RGB.values())) class DHGR560Screen(Screen): """DHGR screen including colour fringing.""" X_RES = 560 Y_RES = 192 X_PIXEL_WIDTH = 1 def _image_to_bitmap(self, image_4bit: np.ndarray) -> np.ndarray: bitmap = np.zeros((self.Y_RES, self.X_RES), dtype=np.bool) for y in range(self.Y_RES): for x in range(self.X_RES): pixel = image_4bit[y, x] dots = DOTS[pixel] phase = x % 4 bitmap[y, x] = dots[phase] return bitmap @staticmethod def pixel_palette_options(last_pixel_4bit, x: int): last_dots = DOTS[last_pixel_4bit] other_dots = list(last_dots) other_dots[x % 4] = not other_dots[x % 4] other_dots = tuple(other_dots) other_pixel_4bit = DOTS_TO_4BIT[other_dots] return ( np.array([last_pixel_4bit, other_pixel_4bit]), np.array([RGB[last_pixel_4bit], RGB[other_pixel_4bit]])) class Dither: PATTERN = None ORIGIN = None class FloydSteinbergDither(Dither): # 0 * 7 # 3 5 1 PATTERN = np.array(((0, 0, 7), (3, 5, 1)), dtype=np.float32).reshape(2, 3, 1) / np.float(16) # XXX X_ORIGIN since ORIGIN[0] == 0 ORIGIN = (0, 1) class BuckelsDither(Dither): # 0 * 2 1 # 1 2 1 0 # 0 1 0 0 PATTERN = np.array(((0, 0, 2, 1), (1, 2, 1, 0), (0, 1, 0, 0)), dtype=np.float32).reshape(3, 4, 1) / np.float32(8) ORIGIN = (0, 1) class JarvisDither(Dither): # 0 0 X 7 5 # 3 5 7 5 3 # 1 3 5 3 1 PATTERN = np.array(((0, 0, 0, 7, 5), (3, 5, 7, 5, 3), (1, 3, 5, 3, 1)), dtype=np.float32).reshape(3, 5, 1) / np.float32(48) ORIGIN = (0, 2) def open_image(screen: Screen, filename: str) -> np.ndarray: im = Image.open(filename) # TODO: convert to sRGB colour profile explicitly, in case it has some other # profile already. if im.mode != "RGB": im = im.convert("RGB") # Convert to linear RGB before rescaling so that colour interpolation is # in linear space linear = srgb_to_linear(np.asarray(im)).astype(np.uint8) rescaled = Image.fromarray(linear).resize( (screen.X_RES, screen.Y_RES), Image.LANCZOS) # XXX work with malloc'ed array? return np.array(rescaled).astype(np.float32) def main(): parser = argparse.ArgumentParser() parser.add_argument("input", type=str, help="Input file to process") parser.add_argument("output", type=str, help="Output file for ") parser.add_argument( "--lookahead", type=int, default=4, help=("How many pixels to look ahead to compensate for NTSC colour " "artifacts.")) args = parser.parse_args() # screen = DHGR140Screen() screen = DHGR560Screen() image = open_image(screen, args.input) # image_rgb.show() # dither = FloydSteinbergDither() # dither = BuckelsDither() dither = JarvisDither() differ = CIE2000Distance() start = time.time() output_4bit, output_rgb = dither_apply.dither_image(screen, image, dither, differ, lookahead=args.lookahead) print(time.time() - start) screen.pack(output_4bit) out_image = Image.fromarray(linear_to_srgb(output_rgb).astype(np.uint8)) outfile = os.path.join(os.path.splitext(args.output)[0] + ".png") out_image.save(outfile, "PNG") out_image.show(title=outfile) # bitmap = Image.fromarray(screen.bitmap.astype('uint8') * 255) with open(args.output, "wb") as f: f.write(bytes(screen.main)) f.write(bytes(screen.aux)) if __name__ == "__main__": main()