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Diffstat (limited to 'lib/Python/Lib/PIL/Jpeg2KImagePlugin.py')
| -rw-r--r-- | lib/Python/Lib/PIL/Jpeg2KImagePlugin.py | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/lib/Python/Lib/PIL/Jpeg2KImagePlugin.py b/lib/Python/Lib/PIL/Jpeg2KImagePlugin.py new file mode 100644 index 000000000..ed3e1530a --- /dev/null +++ b/lib/Python/Lib/PIL/Jpeg2KImagePlugin.py @@ -0,0 +1,276 @@ +# +# The Python Imaging Library +# $Id$ +# +# JPEG2000 file handling +# +# History: +# 2014-03-12 ajh Created +# +# Copyright (c) 2014 Coriolis Systems Limited +# Copyright (c) 2014 Alastair Houghton +# +# See the README file for information on usage and redistribution. +# +from PIL import Image, ImageFile +import struct +import os +import io + +__version__ = "0.1" + + +def _parse_codestream(fp): + """Parse the JPEG 2000 codestream to extract the size and component + count from the SIZ marker segment, returning a PIL (size, mode) tuple.""" + + hdr = fp.read(2) + lsiz = struct.unpack('>H', hdr)[0] + siz = hdr + fp.read(lsiz - 2) + lsiz, rsiz, xsiz, ysiz, xosiz, yosiz, xtsiz, ytsiz, \ + xtosiz, ytosiz, csiz \ + = struct.unpack('>HHIIIIIIIIH', siz[:38]) + ssiz = [None]*csiz + xrsiz = [None]*csiz + yrsiz = [None]*csiz + for i in range(csiz): + ssiz[i], xrsiz[i], yrsiz[i] \ + = struct.unpack('>BBB', siz[36 + 3 * i:39 + 3 * i]) + + size = (xsiz - xosiz, ysiz - yosiz) + if csiz == 1: + if (yrsiz[0] & 0x7f) > 8: + mode = 'I;16' + else: + mode = 'L' + elif csiz == 2: + mode = 'LA' + elif csiz == 3: + mode = 'RGB' + elif csiz == 4: + mode = 'RGBA' + else: + mode = None + + return (size, mode) + + +def _parse_jp2_header(fp): + """Parse the JP2 header box to extract size, component count and + color space information, returning a PIL (size, mode) tuple.""" + + # Find the JP2 header box + header = None + while True: + lbox, tbox = struct.unpack('>I4s', fp.read(8)) + if lbox == 1: + lbox = struct.unpack('>Q', fp.read(8))[0] + hlen = 16 + else: + hlen = 8 + + if lbox < hlen: + raise SyntaxError('Invalid JP2 header length') + + if tbox == b'jp2h': + header = fp.read(lbox - hlen) + break + else: + fp.seek(lbox - hlen, os.SEEK_CUR) + + if header is None: + raise SyntaxError('could not find JP2 header') + + size = None + mode = None + bpc = None + + hio = io.BytesIO(header) + while True: + lbox, tbox = struct.unpack('>I4s', hio.read(8)) + if lbox == 1: + lbox = struct.unpack('>Q', hio.read(8))[0] + hlen = 16 + else: + hlen = 8 + + content = hio.read(lbox - hlen) + + if tbox == b'ihdr': + height, width, nc, bpc, c, unkc, ipr \ + = struct.unpack('>IIHBBBB', content) + size = (width, height) + if unkc: + if nc == 1 and (bpc & 0x7f) > 8: + mode = 'I;16' + elif nc == 1: + mode = 'L' + elif nc == 2: + mode = 'LA' + elif nc == 3: + mode = 'RGB' + elif nc == 4: + mode = 'RGBA' + break + elif tbox == b'colr': + meth, prec, approx = struct.unpack('>BBB', content[:3]) + if meth == 1: + cs = struct.unpack('>I', content[3:7])[0] + if cs == 16: # sRGB + if nc == 1 and (bpc & 0x7f) > 8: + mode = 'I;16' + elif nc == 1: + mode = 'L' + elif nc == 3: + mode = 'RGB' + elif nc == 4: + mode = 'RGBA' + break + elif cs == 17: # grayscale + if nc == 1 and (bpc & 0x7f) > 8: + mode = 'I;16' + elif nc == 1: + mode = 'L' + elif nc == 2: + mode = 'LA' + break + elif cs == 18: # sYCC + if nc == 3: + mode = 'RGB' + elif nc == 4: + mode = 'RGBA' + break + + return (size, mode) + +## +# Image plugin for JPEG2000 images. + + +class Jpeg2KImageFile(ImageFile.ImageFile): + format = "JPEG2000" + format_description = "JPEG 2000 (ISO 15444)" + + def _open(self): + sig = self.fp.read(4) + if sig == b'\xff\x4f\xff\x51': + self.codec = "j2k" + self.size, self.mode = _parse_codestream(self.fp) + else: + sig = sig + self.fp.read(8) + + if sig == b'\x00\x00\x00\x0cjP \x0d\x0a\x87\x0a': + self.codec = "jp2" + self.size, self.mode = _parse_jp2_header(self.fp) + else: + raise SyntaxError('not a JPEG 2000 file') + + if self.size is None or self.mode is None: + raise SyntaxError('unable to determine size/mode') + + self.reduce = 0 + self.layers = 0 + + fd = -1 + length = -1 + + try: + fd = self.fp.fileno() + length = os.fstat(fd).st_size + except: + fd = -1 + try: + pos = self.fp.tell() + self.fp.seek(0, 2) + length = self.fp.tell() + self.fp.seek(pos, 0) + except: + length = -1 + + self.tile = [('jpeg2k', (0, 0) + self.size, 0, + (self.codec, self.reduce, self.layers, fd, length))] + + def load(self): + if self.reduce: + power = 1 << self.reduce + adjust = power >> 1 + self.size = (int((self.size[0] + adjust) / power), + int((self.size[1] + adjust) / power)) + + if self.tile: + # Update the reduce and layers settings + t = self.tile[0] + t3 = (t[3][0], self.reduce, self.layers, t[3][3], t[3][4]) + self.tile = [(t[0], (0, 0) + self.size, t[2], t3)] + + ImageFile.ImageFile.load(self) + + +def _accept(prefix): + return (prefix[:4] == b'\xff\x4f\xff\x51' or + prefix[:12] == b'\x00\x00\x00\x0cjP \x0d\x0a\x87\x0a') + + +# ------------------------------------------------------------ +# Save support + +def _save(im, fp, filename): + if filename.endswith('.j2k'): + kind = 'j2k' + else: + kind = 'jp2' + + # Get the keyword arguments + info = im.encoderinfo + + offset = info.get('offset', None) + tile_offset = info.get('tile_offset', None) + tile_size = info.get('tile_size', None) + quality_mode = info.get('quality_mode', 'rates') + quality_layers = info.get('quality_layers', None) + num_resolutions = info.get('num_resolutions', 0) + cblk_size = info.get('codeblock_size', None) + precinct_size = info.get('precinct_size', None) + irreversible = info.get('irreversible', False) + progression = info.get('progression', 'LRCP') + cinema_mode = info.get('cinema_mode', 'no') + fd = -1 + + if hasattr(fp, "fileno"): + try: + fd = fp.fileno() + except: + fd = -1 + + im.encoderconfig = ( + offset, + tile_offset, + tile_size, + quality_mode, + quality_layers, + num_resolutions, + cblk_size, + precinct_size, + irreversible, + progression, + cinema_mode, + fd + ) + + ImageFile._save(im, fp, [('jpeg2k', (0, 0)+im.size, 0, kind)]) + +# ------------------------------------------------------------ +# Registry stuff + +Image.register_open('JPEG2000', Jpeg2KImageFile, _accept) +Image.register_save('JPEG2000', _save) + +Image.register_extension('JPEG2000', '.jp2') +Image.register_extension('JPEG2000', '.j2k') +Image.register_extension('JPEG2000', '.jpc') +Image.register_extension('JPEG2000', '.jpf') +Image.register_extension('JPEG2000', '.jpx') +Image.register_extension('JPEG2000', '.j2c') + +Image.register_mime('JPEG2000', 'image/jp2') +Image.register_mime('JPEG2000', 'image/jpx') |