# # The Python Imaging Library. # # QOI support for PIL # # See the README file for information on usage and redistribution. # from __future__ import annotations import os from typing import IO from . import Image, ImageFile from ._binary import i32be as i32 from ._binary import o8 from ._binary import o32be as o32 def _accept(prefix: bytes) -> bool: return prefix.startswith(b"qoif") class QoiImageFile(ImageFile.ImageFile): format = "QOI" format_description = "Quite OK Image" def _open(self) -> None: if not _accept(self.fp.read(4)): msg = "not a QOI file" raise SyntaxError(msg) self._size = i32(self.fp.read(4)), i32(self.fp.read(4)) channels = self.fp.read(1)[0] self._mode = "RGB" if channels == 3 else "RGBA" self.fp.seek(1, os.SEEK_CUR) # colorspace self.tile = [ImageFile._Tile("qoi", (0, 0) + self._size, self.fp.tell())] class QoiDecoder(ImageFile.PyDecoder): _pulls_fd = True _previous_pixel: bytes | bytearray | None = None _previously_seen_pixels: dict[int, bytes | bytearray] = {} def _add_to_previous_pixels(self, value: bytes | bytearray) -> None: self._previous_pixel = value r, g, b, a = value hash_value = (r * 3 + g * 5 + b * 7 + a * 11) % 64 self._previously_seen_pixels[hash_value] = value def decode(self, buffer: bytes | Image.SupportsArrayInterface) -> tuple[int, int]: assert self.fd is not None self._previously_seen_pixels = {} self._previous_pixel = bytearray((0, 0, 0, 255)) data = bytearray() bands = Image.getmodebands(self.mode) dest_length = self.state.xsize * self.state.ysize * bands while len(data) < dest_length: byte = self.fd.read(1)[0] value: bytes | bytearray if byte == 0b11111110 and self._previous_pixel: # QOI_OP_RGB value = bytearray(self.fd.read(3)) + self._previous_pixel[3:] elif byte == 0b11111111: # QOI_OP_RGBA value = self.fd.read(4) else: op = byte >> 6 if op == 0: # QOI_OP_INDEX op_index = byte & 0b00111111 value = self._previously_seen_pixels.get( op_index, bytearray((0, 0, 0, 0)) ) elif op == 1 and self._previous_pixel: # QOI_OP_DIFF value = bytearray( ( (self._previous_pixel[0] + ((byte & 0b00110000) >> 4) - 2) % 256, (self._previous_pixel[1] + ((byte & 0b00001100) >> 2) - 2) % 256, (self._previous_pixel[2] + (byte & 0b00000011) - 2) % 256, self._previous_pixel[3], ) ) elif op == 2 and self._previous_pixel: # QOI_OP_LUMA second_byte = self.fd.read(1)[0] diff_green = (byte & 0b00111111) - 32 diff_red = ((second_byte & 0b11110000) >> 4) - 8 diff_blue = (second_byte & 0b00001111) - 8 value = bytearray( tuple( (self._previous_pixel[i] + diff_green + diff) % 256 for i, diff in enumerate((diff_red, 0, diff_blue)) ) ) value += self._previous_pixel[3:] elif op == 3 and self._previous_pixel: # QOI_OP_RUN run_length = (byte & 0b00111111) + 1 value = self._previous_pixel if bands == 3: value = value[:3] data += value * run_length continue self._add_to_previous_pixels(value) if bands == 3: value = value[:3] data += value self.set_as_raw(data) return -1, 0 def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None: if im.mode == "RGB": channels = 3 elif im.mode == "RGBA": channels = 4 else: msg = "Unsupported QOI image mode" raise ValueError(msg) colorspace = 0 if im.encoderinfo.get("colorspace") == "sRGB" else 1 fp.write(b"qoif") fp.write(o32(im.size[0])) fp.write(o32(im.size[1])) fp.write(o8(channels)) fp.write(o8(colorspace)) ImageFile._save(im, fp, [ImageFile._Tile("qoi", (0, 0) + im.size)]) class QoiEncoder(ImageFile.PyEncoder): _pushes_fd = True _previous_pixel: tuple[int, int, int, int] | None = None _previously_seen_pixels: dict[int, tuple[int, int, int, int]] = {} _run = 0 def _write_run(self) -> bytes: data = o8(0b11000000 | (self._run - 1)) # QOI_OP_RUN self._run = 0 return data def _delta(self, left: int, right: int) -> int: result = (left - right) & 255 if result >= 128: result -= 256 return result def encode(self, bufsize: int) -> tuple[int, int, bytes]: assert self.im is not None self._previously_seen_pixels = {0: (0, 0, 0, 0)} self._previous_pixel = (0, 0, 0, 255) data = bytearray() w, h = self.im.size bands = Image.getmodebands(self.mode) for y in range(h): for x in range(w): pixel = self.im.getpixel((x, y)) if bands == 3: pixel = (*pixel, 255) if pixel == self._previous_pixel: self._run += 1 if self._run == 62: data += self._write_run() else: if self._run: data += self._write_run() r, g, b, a = pixel hash_value = (r * 3 + g * 5 + b * 7 + a * 11) % 64 if self._previously_seen_pixels.get(hash_value) == pixel: data += o8(hash_value) # QOI_OP_INDEX elif self._previous_pixel: self._previously_seen_pixels[hash_value] = pixel prev_r, prev_g, prev_b, prev_a = self._previous_pixel if prev_a == a: delta_r = self._delta(r, prev_r) delta_g = self._delta(g, prev_g) delta_b = self._delta(b, prev_b) if ( -2 <= delta_r < 2 and -2 <= delta_g < 2 and -2 <= delta_b < 2 ): data += o8( 0b01000000 | (delta_r + 2) << 4 | (delta_g + 2) << 2 | (delta_b + 2) ) # QOI_OP_DIFF else: delta_gr = self._delta(delta_r, delta_g) delta_gb = self._delta(delta_b, delta_g) if ( -8 <= delta_gr < 8 and -32 <= delta_g < 32 and -8 <= delta_gb < 8 ): data += o8( 0b10000000 | (delta_g + 32) ) # QOI_OP_LUMA data += o8((delta_gr + 8) << 4 | (delta_gb + 8)) else: data += o8(0b11111110) # QOI_OP_RGB data += bytes(pixel[:3]) else: data += o8(0b11111111) # QOI_OP_RGBA data += bytes(pixel) self._previous_pixel = pixel if self._run: data += self._write_run() data += bytes((0, 0, 0, 0, 0, 0, 0, 1)) # padding return len(data), 0, data Image.register_open(QoiImageFile.format, QoiImageFile, _accept) Image.register_decoder("qoi", QoiDecoder) Image.register_extension(QoiImageFile.format, ".qoi") Image.register_save(QoiImageFile.format, _save) Image.register_encoder("qoi", QoiEncoder)