mirror of
https://github.com/python-pillow/Pillow.git
synced 2024-12-26 01:46:18 +03:00
Use 1 and not P for basic 1bpp BMP
Readapted some original code.
This commit is contained in:
artscoop
parent
56439b728f
commit
934651427d
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@ -23,13 +23,12 @@
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# See the README file for information on usage and redistribution.
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#
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__version__ = "0.7"
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from PIL import Image, ImageFile, ImagePalette, _binary
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import math
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i8 = _binary.i8
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i16 = _binary.i16le
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i32 = _binary.i32le
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@ -56,131 +55,147 @@ def _accept(prefix):
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return prefix[:2] == b"BM"
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##
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#===============================================================================
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# Image plugin for the Windows BMP format.
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#===============================================================================
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class BmpImageFile(ImageFile.ImageFile):
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format = "BMP"
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""" Image plugin for the Windows Bitmap format (BMP) """
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#--------------------------------------------------------------- Description
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format_description = "Windows Bitmap"
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def _bitmap(self, header=0, offset=0):
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if header:
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self.fp.seek(header)
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read = self.fp.read
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# CORE/INFO
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s = read(4)
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s = s + ImageFile._safe_read(self.fp, i32(s)-4)
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if len(s) == 12:
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# OS/2 1.0 CORE
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bits = i16(s[10:])
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self.size = i16(s[4:]), i16(s[6:])
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compression = 0
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lutsize = 3
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colors = 0
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direction = -1
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elif len(s) in [40, 64, 108, 124]:
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# WIN 3.1 or OS/2 2.0 INFO
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bits = i16(s[14:])
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self.size = i32(s[4:]), i32(s[8:])
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compression = i32(s[16:])
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pxperm = (i32(s[24:]), i32(s[28:])) # Pixels per meter
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lutsize = 4
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colors = i32(s[32:])
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direction = -1
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if i8(s[11]) == 0xff:
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# upside-down storage
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self.size = self.size[0], 2**32 - self.size[1]
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direction = 0
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self.info["dpi"] = tuple(map(lambda x: math.ceil(x / 39.3701),
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pxperm))
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else:
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raise IOError("Unsupported BMP header type (%d)" % len(s))
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if (self.size[0]*self.size[1]) > 2**31:
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# Prevent DOS for > 2gb images
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raise IOError("Unsupported BMP Size: (%dx%d)" % self.size)
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if not colors:
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colors = 1 << bits
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# MODE
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try:
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self.mode, rawmode = BIT2MODE[bits]
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except KeyError:
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raise IOError("Unsupported BMP pixel depth (%d)" % bits)
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if compression == 3:
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# BI_BITFIELDS compression
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mask = i32(read(4)), i32(read(4)), i32(read(4))
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if bits == 32 and mask == (0xff0000, 0x00ff00, 0x0000ff):
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rawmode = "BGRX"
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elif bits == 16 and mask == (0x00f800, 0x0007e0, 0x00001f):
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rawmode = "BGR;16"
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elif bits == 16 and mask == (0x007c00, 0x0003e0, 0x00001f):
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rawmode = "BGR;15"
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else:
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# print bits, map(hex, mask)
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raise IOError("Unsupported BMP bitfields layout")
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elif compression != 0:
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raise IOError("Unsupported BMP compression (%d)" % compression)
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# LUT
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if self.mode == "P":
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palette = []
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greyscale = 1
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if colors == 2:
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indices = (0, 255)
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elif colors > 2**16 or colors <= 0: # We're reading a i32.
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raise IOError("Unsupported BMP Palette size (%d)" % colors)
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else:
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indices = list(range(colors))
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for i in indices:
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rgb = read(lutsize)[:3]
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if rgb != o8(i)*3:
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greyscale = 0
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palette.append(rgb)
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if greyscale:
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if colors == 2:
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self.mode = rawmode = "1"
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else:
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self.mode = rawmode = "L"
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else:
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self.mode = "P"
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self.palette = ImagePalette.raw(
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"BGR", b"".join(palette)
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)
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if not offset:
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offset = self.fp.tell()
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self.tile = [("raw",
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(0, 0) + self.size,
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offset,
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(rawmode, ((self.size[0]*bits+31) >> 3) & (~3),
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direction))]
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self.info["compression"] = compression
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format = "BMP"
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#---------------------------------------------------- BMP Compression values
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COMPRESSIONS = {'RAW': 0, 'RLE8': 1, 'RLE4': 2, 'BITFIELDS': 3, 'JPEG': 4, 'PNG': 5}
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RAW, RLE8, RLE4, BITFIELDS, JPEG, PNG = 0, 1, 2, 3, 4, 5
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def _open(self):
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# HEAD
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s = self.fp.read(14)
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if s[:2] != b"BM":
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raise SyntaxError("Not a BMP file")
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offset = i32(s[10:])
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""" Open file, check magic number and read header """
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# read 14 bytes: magic number, filesize, reserved, header final offset
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head_data = self.fp.read(14)
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# choke if the file does not have the required magic bytes
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if head_data[0:2] != b"BM":
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raise SyntaxError("Expected a BMP file.")
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# read the start position of the BMP image data (u32)
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offset = i32(head_data[10:14])
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# load bitmap information (offset=raster info)
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self._bitmap(offset=offset)
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def _bitmap(self, header=0, offset=0):
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""" Read relevant info about the BMP """
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read, seek = self.fp.read, self.fp.seek
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seek(2)
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start_data = read(12)
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file_info = dict()
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file_info['filesize'] = i32(start_data[0:4]) # file size @offset 2 (offsets 4, 12 are reserved for OS/2 Icons)
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file_info['image_offset'] = i32(start_data[8:12]) # file size @offset 2 (offsets 4, 12 are reserved for OS/2 Icons)
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file_info['header_size'] = i32(read(4)) # read bmp header size @offset 14 (this is part of the header size)
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file_info['direction'] = -1
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header_data = ImageFile._safe_read(self.fp, file_info['header_size'] - 4) # read the rest of the bmp header, without its size
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#---------------------------------------------------- IBM OS/2 Bitmap v1
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#------- This format has different offsets because of width/height types
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if file_info['header_size'] == 12:
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file_info['width'] = i16(header_data[0:2])
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file_info['height'] = i16(header_data[2:4])
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file_info['planes'] = i16(header_data[4:6])
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file_info['bits'] = i16(header_data[6:8])
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file_info['compression'] = self.RAW
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file_info['palette_padding'] = 3
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#----------------------------------------------- Windows Bitmap v2 to v5
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elif file_info['header_size'] in {40, 64, 108, 124}: # v3, OS/2 v2, v4, v5
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if file_info['header_size'] >= 64:
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file_info['r_mask'] = i32(header_data[36:40])
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file_info['g_mask'] = i32(header_data[40:44])
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file_info['b_mask'] = i32(header_data[44:48])
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file_info['a_mask'] = i32(header_data[48:52])
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file_info['rgb_mask'] = (file_info['r_mask'], file_info['g_mask'], file_info['b_mask'])
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file_info['rgba_mask'] = (file_info['r_mask'], file_info['g_mask'], file_info['b_mask'], file_info['a_mask'])
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if file_info['header_size'] >= 40: # v3 and OS/2
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file_info['y_flip'] = i8(header_data[7]) == 0xff
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file_info['direction'] = 1 if file_info['y_flip'] else -1
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file_info['width'] = i32(header_data[0:4])
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file_info['height'] = i32(header_data[4:8]) if not file_info['y_flip'] else 2**32 - i32(header_data[4:8])
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file_info['planes'] = i16(header_data[8:10])
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file_info['bits'] = i16(header_data[10:12])
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file_info['compression'] = i32(header_data[12:16])
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file_info['data_size'] = i32(header_data[16:20]) # byte size of pixel data
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file_info['pixels_per_meter'] = (i32(header_data[20:24]), i32(header_data[24:28]))
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file_info['colors'] = i32(header_data[28:32])
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file_info['palette_padding'] = 4
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#------------------- Special case : header is reported 40, which
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#----------------------- is shorter than real size for bpp >= 16
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if file_info['header_size'] < 64 and file_info['bits'] >= 16:
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file_info['r_mask'] = i32(read(4))
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file_info['g_mask'] = i32(read(4))
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file_info['b_mask'] = i32(read(4))
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file_info['a_mask'] = i32(read(4))
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file_info['rgb_mask'] = (file_info['r_mask'], file_info['g_mask'], file_info['b_mask'])
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file_info['rgba_mask'] = (file_info['r_mask'], file_info['g_mask'], file_info['b_mask'], file_info['a_mask'])
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self.info["dpi"] = tuple(map(lambda x: math.ceil(x / 39.3701), file_info['pixels_per_meter']))
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else:
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raise IOError("BMP images with a {0} byte header are not supported".format(file_info['header_size']))
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self.size = file_info['width'], file_info['height']
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#--------- If color count was not found in the header, compute from bits
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file_info['colors'] = file_info['colors'] if file_info.get('colors', 0) else (1 << file_info['bits'])
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#--------------------------------- Check abnormal values for DOS attacks
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if file_info['width'] * file_info['height'] > 2**31:
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raise IOError("BMP images with more than 2 billion pixels are not supported (here {0} pixels)".format(file_info['width'] * file_info['height']))
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#------------------------ Check bit depth for unusual unsupported values
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self.mode, raw_mode = BIT2MODE.get(file_info['bits'], (None, None))
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if self.mode is None:
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raise IOError("BMP images with a {0}-bit pixel depth are not supported".format(file_info['bits']))
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#------------------ Process BMP with Bitfields compression (not palette)
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if file_info['compression'] == self.BITFIELDS:
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SUPPORTED = {32: [(0xff0000, 0xff00, 0xff, 0x0), (0xff0000, 0xff00, 0xff, 0xff000000)], 24: [(0xff0000, 0xff00, 0xff)], 16: [(0xf800, 0x7e0, 0x1f), (0x7c00, 0x3e0, 0x1f)]}
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MASK_MODES = {(32, (0xff0000, 0xff00, 0xff, 0x0)): "BGRX", (32, (0xff0000, 0xff00, 0xff, 0xff000000)): "BGRA", (24, (0xff0000, 0xff00, 0xff)): "BGR", (16, (0xf800, 0x7e0, 0x1f)): "BGR;16", (16, (0x7c00, 0x3e0, 0x1f)): "BGR;15"}
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if file_info['bits'] in SUPPORTED:
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if file_info['bits'] == 32 and file_info['rgba_mask'] in SUPPORTED[file_info['bits']]:
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raw_mode = MASK_MODES[(file_info['bits'], file_info['rgba_mask'])]
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self.mode = "RGBA" if raw_mode in ("BGRA",) else self.mode
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elif file_info['bits'] in (24, 16) and file_info['rgb_mask'] in SUPPORTED[file_info['bits']]:
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raw_mode = MASK_MODES[(file_info['bits'], file_info['rgb_mask'])]
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else:
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raise IOError("BMP images with the provided bitfield mask are not supported")
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else:
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raise IOError("BMP images with the provided bitfield information are not supported")
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elif file_info['compression'] != self.RAW:
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raise IOError("BMP files with RLE (1/2), JPEG (4) and PNG (5) compression are not supported")
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#----------------- Once the header is processed, process the palette/LUT
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if self.mode == "P": # Paletted for 1, 4 and 8 bit images
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#------------------------------------------------------ 1-bit images
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if not (0 < file_info['colors'] <= 65536):
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raise IOError("BMP palette must have between 1 and 256 colors")
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else:
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padding = file_info['palette_padding']
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palette = read(padding * file_info['colors'])
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greyscale = True
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indices = (0, 255) if file_info['colors'] == 2 else list(range(file_info['colors']))
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#------------------- Check if greyscale and ignore palette if so
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for ind, val in enumerate(indices):
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rgb = palette[ind*padding:ind*padding + 3]
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if rgb != o8(val) * 3:
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greyscale = False
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#--------- If all colors are grey, white or black, ditch palette
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if greyscale:
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self.mode = "1" if file_info['colors'] == 2 else "L"
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raw_mode = self.mode
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else:
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self.mode = "P"
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self.palette = ImagePalette.raw("BGRX" if padding == 4 else "BGR", b"".join(palette))
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#------------------------------ Finally set the tile data for the plugin
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self.info['compression'] = file_info['compression']
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self.tile = [('raw', (0, 0, file_info['width'], file_info['height']), file_info['image_offset'],
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(raw_mode, ((file_info['width'] * file_info['bits'] + 31) >> 3) & (~3), file_info['direction'])
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)]
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#===============================================================================
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# Image plugin for the DIB format (BMP alias)
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#===============================================================================
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class DibImageFile(BmpImageFile):
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format = "DIB"
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@ -189,6 +204,8 @@ class DibImageFile(BmpImageFile):
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def _open(self):
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self._bitmap()
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#
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# --------------------------------------------------------------------
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# Write BMP file
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@ -198,6 +215,7 @@ SAVE = {
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"L": ("L", 8, 256),
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"P": ("P", 8, 256),
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"RGB": ("BGR", 24, 0),
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"RGBA": ("BGRA", 32, 0),
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}
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