From 78430b954956313795a2e76c9398264de3316e0e Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Sat, 22 Oct 2022 18:50:17 +1100 Subject: [PATCH 1/2] Corrected BMP compression setting [ci skip] --- docs/handbook/image-file-formats.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst index e365aad569d..1e79db68bcb 100644 --- a/docs/handbook/image-file-formats.rst +++ b/docs/handbook/image-file-formats.rst @@ -56,8 +56,8 @@ The :py:meth:`~PIL.Image.open` method sets the following :py:attr:`~PIL.Image.Image.info` properties: **compression** - Set to ``bmp_rle8`` if the file is a 256-color run-length encoded image. - Set to ``bmp_rle4`` if the file is a 16-color run-length encoded image. + Set to 1 if the file is a 256-color run-length encoded image. + Set to 2 if the file is a 16-color run-length encoded image. DDS ^^^ From 6c8234bef3d4b3c4c1672cea1103aadfa59f0f7c Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Sat, 22 Oct 2022 19:54:54 +1100 Subject: [PATCH 2/2] Combined BMP RLE decoders --- src/PIL/BmpImagePlugin.py | 113 ++++++++++++-------------------------- 1 file changed, 34 insertions(+), 79 deletions(-) diff --git a/src/PIL/BmpImagePlugin.py b/src/PIL/BmpImagePlugin.py index 9d780bccac3..1eeab24a7c0 100644 --- a/src/PIL/BmpImagePlugin.py +++ b/src/PIL/BmpImagePlugin.py @@ -211,10 +211,8 @@ def _bitmap(self, header=0, offset=0): elif file_info["compression"] == self.RAW: if file_info["bits"] == 32 and header == 22: # 32-bit .cur offset raw_mode, self.mode = "BGRA", "RGBA" - elif file_info["compression"] == self.RLE8: - decoder_name = "bmp_rle8" - elif file_info["compression"] == self.RLE4: - decoder_name = "bmp_rle4" + elif file_info["compression"] in (self.RLE8, self.RLE4): + decoder_name = "bmp_rle" else: raise OSError(f"Unsupported BMP compression ({file_info['compression']})") @@ -252,16 +250,18 @@ def _bitmap(self, header=0, offset=0): # ---------------------------- Finally set the tile data for the plugin self.info["compression"] = file_info["compression"] + args = [raw_mode] + if decoder_name == "bmp_rle": + args.append(file_info["compression"] == self.RLE4) + else: + args.append(((file_info["width"] * file_info["bits"] + 31) >> 3) & (~3)) + args.append(file_info["direction"]) self.tile = [ ( decoder_name, (0, 0, file_info["width"], file_info["height"]), offset or self.fp.tell(), - ( - raw_mode, - ((file_info["width"] * file_info["bits"] + 31) >> 3) & (~3), - file_info["direction"], - ), + tuple(args), ) ] @@ -278,10 +278,11 @@ def _open(self): self._bitmap(offset=offset) -class BmpRle8Decoder(ImageFile.PyDecoder): +class BmpRleDecoder(ImageFile.PyDecoder): _pulls_fd = True def decode(self, buffer): + rle4 = self.args[1] data = bytearray() x = 0 while len(data) < self.state.xsize * self.state.ysize: @@ -295,67 +296,19 @@ def decode(self, buffer): if x + num_pixels > self.state.xsize: # Too much data for row num_pixels = max(0, self.state.xsize - x) - data += byte * num_pixels - x += num_pixels - else: - if byte[0] == 0: - # end of line - while len(data) % self.state.xsize != 0: - data += b"\x00" - x = 0 - elif byte[0] == 1: - # end of bitmap - break - elif byte[0] == 2: - # delta - bytes_read = self.fd.read(2) - if len(bytes_read) < 2: - break - right, up = self.fd.read(2) - data += b"\x00" * (right + up * self.state.xsize) - x = len(data) % self.state.xsize + if rle4: + first_pixel = o8(byte[0] >> 4) + second_pixel = o8(byte[0] & 0x0F) + for index in range(num_pixels): + if index % 2 == 0: + data += first_pixel + else: + data += second_pixel else: - # absolute mode - bytes_read = self.fd.read(byte[0]) - data += bytes_read - if len(bytes_read) < byte[0]: - break - x += byte[0] - - # align to 16-bit word boundary - if self.fd.tell() % 2 != 0: - self.fd.seek(1, os.SEEK_CUR) - rawmode = "L" if self.mode == "L" else "P" - self.set_as_raw(bytes(data), (rawmode, 0, self.args[-1])) - return -1, 0 - - -class BmpRle4Decoder(ImageFile.PyDecoder): - _pulls_fd = True - - def decode(self, buffer): - data = bytearray() - x = 0 - while len(data) < self.state.xsize * self.state.ysize: - pixels = self.fd.read(1) - byte = self.fd.read(1) - if not pixels or not byte: - break - num_pixels = pixels[0] - if num_pixels: - # encoded mode - if x + num_pixels > self.state.xsize: - # Too much data for row - num_pixels = max(0, self.state.xsize - x) - first_pixel = o8(byte[0] >> 4) - second_pixel = o8(byte[0] & 0x0F) - for index in range(num_pixels): - if index % 2 == 0: - data += first_pixel - else: - data += second_pixel + data += byte * num_pixels x += num_pixels else: + # absolute mode if byte[0] == 0: # end of line while len(data) % self.state.xsize != 0: @@ -373,15 +326,18 @@ def decode(self, buffer): data += b"\x00" * (right + up * self.state.xsize) x = len(data) % self.state.xsize else: - # absolute mode (2 pixels per byte) - total_bytes_to_read = byte[0] // 2 - bytes_read = self.fd.read(total_bytes_to_read) - for byte_read in bytes_read: - first_pixel = o8(byte_read >> 4) - data += first_pixel - second_pixel = o8(byte_read & 0x0F) - data += second_pixel - if len(bytes_read) < total_bytes_to_read: + if rle4: + # 2 pixels per byte + byte_count = byte[0] // 2 + bytes_read = self.fd.read(byte_count) + for byte_read in bytes_read: + data += o8(byte_read >> 4) + data += o8(byte_read & 0x0F) + else: + byte_count = byte[0] + bytes_read = self.fd.read(byte_count) + data += bytes_read + if len(bytes_read) < byte_count: break x += byte[0] @@ -498,8 +454,7 @@ def _save(im, fp, filename, bitmap_header=True): Image.register_mime(BmpImageFile.format, "image/bmp") -Image.register_decoder("bmp_rle8", BmpRle8Decoder) -Image.register_decoder("bmp_rle4", BmpRle4Decoder) +Image.register_decoder("bmp_rle", BmpRleDecoder) Image.register_open(DibImageFile.format, DibImageFile, _dib_accept) Image.register_save(DibImageFile.format, _dib_save)