Source code for PIL.JpegImagePlugin

#
# The Python Imaging Library.
# $Id$
#
# JPEG (JFIF) file handling
#
# See "Digital Compression and Coding of Continuous-Tone Still Images,
# Part 1, Requirements and Guidelines" (CCITT T.81 / ISO 10918-1)
#
# History:
# 1995-09-09 fl   Created
# 1995-09-13 fl   Added full parser
# 1996-03-25 fl   Added hack to use the IJG command line utilities
# 1996-05-05 fl   Workaround Photoshop 2.5 CMYK polarity bug
# 1996-05-28 fl   Added draft support, JFIF version (0.1)
# 1996-12-30 fl   Added encoder options, added progression property (0.2)
# 1997-08-27 fl   Save mode 1 images as BW (0.3)
# 1998-07-12 fl   Added YCbCr to draft and save methods (0.4)
# 1998-10-19 fl   Don't hang on files using 16-bit DQT's (0.4.1)
# 2001-04-16 fl   Extract DPI settings from JFIF files (0.4.2)
# 2002-07-01 fl   Skip pad bytes before markers; identify Exif files (0.4.3)
# 2003-04-25 fl   Added experimental EXIF decoder (0.5)
# 2003-06-06 fl   Added experimental EXIF GPSinfo decoder
# 2003-09-13 fl   Extract COM markers
# 2009-09-06 fl   Added icc_profile support (from Florian Hoech)
# 2009-03-06 fl   Changed CMYK handling; always use Adobe polarity (0.6)
# 2009-03-08 fl   Added subsampling support (from Justin Huff).
#
# Copyright (c) 1997-2003 by Secret Labs AB.
# Copyright (c) 1995-1996 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
import array
import io
import math
import os
import struct
import subprocess
import sys
import tempfile
import warnings

from . import Image, ImageFile, TiffImagePlugin
from ._binary import i16be as i16
from ._binary import i32be as i32
from ._binary import o8
from ._binary import o16be as o16
from ._deprecate import deprecate
from .JpegPresets import presets

#
# Parser





[docs]def APP(self, marker): # # Application marker. Store these in the APP dictionary. # Also look for well-known application markers. n = i16(self.fp.read(2)) - 2 s = ImageFile._safe_read(self.fp, n) app = "APP%d" % (marker & 15) self.app[app] = s # compatibility self.applist.append((app, s)) if marker == 0xFFE0 and s[:4] == b"JFIF": # extract JFIF information self.info["jfif"] = version = i16(s, 5) # version self.info["jfif_version"] = divmod(version, 256) # extract JFIF properties try: jfif_unit = s[7] jfif_density = i16(s, 8), i16(s, 10) except Exception: pass else: if jfif_unit == 1: self.info["dpi"] = jfif_density self.info["jfif_unit"] = jfif_unit self.info["jfif_density"] = jfif_density elif marker == 0xFFE1 and s[:5] == b"Exif\0": if "exif" not in self.info: # extract EXIF information (incomplete) self.info["exif"] = s # FIXME: value will change self._exif_offset = self.fp.tell() - n + 6 elif marker == 0xFFE2 and s[:5] == b"FPXR\0": # extract FlashPix information (incomplete) self.info["flashpix"] = s # FIXME: value will change elif marker == 0xFFE2 and s[:12] == b"ICC_PROFILE\0": # Since an ICC profile can be larger than the maximum size of # a JPEG marker (64K), we need provisions to split it into # multiple markers. The format defined by the ICC specifies # one or more APP2 markers containing the following data: # Identifying string ASCII "ICC_PROFILE\0" (12 bytes) # Marker sequence number 1, 2, etc (1 byte) # Number of markers Total of APP2's used (1 byte) # Profile data (remainder of APP2 data) # Decoders should use the marker sequence numbers to # reassemble the profile, rather than assuming that the APP2 # markers appear in the correct sequence. self.icclist.append(s) elif marker == 0xFFED and s[:14] == b"Photoshop 3.0\x00": # parse the image resource block offset = 14 photoshop = self.info.setdefault("photoshop", {}) while s[offset : offset + 4] == b"8BIM": try: offset += 4 # resource code code = i16(s, offset) offset += 2 # resource name (usually empty) name_len = s[offset] # name = s[offset+1:offset+1+name_len] offset += 1 + name_len offset += offset & 1 # align # resource data block size = i32(s, offset) offset += 4 data = s[offset : offset + size] if code == 0x03ED: # ResolutionInfo data = { "XResolution": i32(data, 0) / 65536, "DisplayedUnitsX": i16(data, 4), "YResolution": i32(data, 8) / 65536, "DisplayedUnitsY": i16(data, 12), } photoshop[code] = data offset += size offset += offset & 1 # align except struct.error: break # insufficient data elif marker == 0xFFEE and s[:5] == b"Adobe": self.info["adobe"] = i16(s, 5) # extract Adobe custom properties try: adobe_transform = s[11] except IndexError: pass else: self.info["adobe_transform"] = adobe_transform elif marker == 0xFFE2 and s[:4] == b"MPF\0": # extract MPO information self.info["mp"] = s[4:] # offset is current location minus buffer size # plus constant header size self.info["mpoffset"] = self.fp.tell() - n + 4 # If DPI isn't in JPEG header, fetch from EXIF if "dpi" not in self.info and "exif" in self.info: try: exif = self.getexif() resolution_unit = exif[0x0128] x_resolution = exif[0x011A] try: dpi = float(x_resolution[0]) / x_resolution[1] except TypeError: dpi = x_resolution if math.isnan(dpi): raise ValueError if resolution_unit == 3: # cm # 1 dpcm = 2.54 dpi dpi *= 2.54 self.info["dpi"] = dpi, dpi except (TypeError, KeyError, SyntaxError, ValueError, ZeroDivisionError): # SyntaxError for invalid/unreadable EXIF # KeyError for dpi not included # ZeroDivisionError for invalid dpi rational value # ValueError or TypeError for dpi being an invalid float self.info["dpi"] = 72, 72
[docs]def COM(self, marker): # # Comment marker. Store these in the APP dictionary. n = i16(self.fp.read(2)) - 2 s = ImageFile._safe_read(self.fp, n) self.info["comment"] = s self.app["COM"] = s # compatibility self.applist.append(("COM", s))
[docs]def SOF(self, marker): # # Start of frame marker. Defines the size and mode of the # image. JPEG is colour blind, so we use some simple # heuristics to map the number of layers to an appropriate # mode. Note that this could be made a bit brighter, by # looking for JFIF and Adobe APP markers. n = i16(self.fp.read(2)) - 2 s = ImageFile._safe_read(self.fp, n) self._size = i16(s, 3), i16(s, 1) self.bits = s[0] if self.bits != 8: msg = f"cannot handle {self.bits}-bit layers" raise SyntaxError(msg) self.layers = s[5] if self.layers == 1: self.mode = "L" elif self.layers == 3: self.mode = "RGB" elif self.layers == 4: self.mode = "CMYK" else: msg = f"cannot handle {self.layers}-layer images" raise SyntaxError(msg) if marker in [0xFFC2, 0xFFC6, 0xFFCA, 0xFFCE]: self.info["progressive"] = self.info["progression"] = 1 if self.icclist: # fixup icc profile self.icclist.sort() # sort by sequence number if self.icclist[0][13] == len(self.icclist): profile = [] for p in self.icclist: profile.append(p[14:]) icc_profile = b"".join(profile) else: icc_profile = None # wrong number of fragments self.info["icc_profile"] = icc_profile self.icclist = [] for i in range(6, len(s), 3): t = s[i : i + 3] # 4-tuples: id, vsamp, hsamp, qtable self.layer.append((t[0], t[1] // 16, t[1] & 15, t[2]))
[docs]def DQT(self, marker): # # Define quantization table. Note that there might be more # than one table in each marker. # FIXME: The quantization tables can be used to estimate the # compression quality. n = i16(self.fp.read(2)) - 2 s = ImageFile._safe_read(self.fp, n) while len(s): v = s[0] precision = 1 if (v // 16 == 0) else 2 # in bytes qt_length = 1 + precision * 64 if len(s) < qt_length: msg = "bad quantization table marker" raise SyntaxError(msg) data = array.array("B" if precision == 1 else "H", s[1:qt_length]) if sys.byteorder == "little" and precision > 1: data.byteswap() # the values are always big-endian self.quantization[v & 15] = [data[i] for i in zigzag_index] s = s[qt_length:]
# # JPEG marker table MARKER = { 0xFFC0: ("SOF0", "Baseline DCT", SOF), 0xFFC1: ("SOF1", "Extended Sequential DCT", SOF), 0xFFC2: ("SOF2", "Progressive DCT", SOF), 0xFFC3: ("SOF3", "Spatial lossless", SOF), 0xFFC4: ("DHT", "Define Huffman table", Skip), 0xFFC5: ("SOF5", "Differential sequential DCT", SOF), 0xFFC6: ("SOF6", "Differential progressive DCT", SOF), 0xFFC7: ("SOF7", "Differential spatial", SOF), 0xFFC8: ("JPG", "Extension", None), 0xFFC9: ("SOF9", "Extended sequential DCT (AC)", SOF), 0xFFCA: ("SOF10", "Progressive DCT (AC)", SOF), 0xFFCB: ("SOF11", "Spatial lossless DCT (AC)", SOF), 0xFFCC: ("DAC", "Define arithmetic coding conditioning", Skip), 0xFFCD: ("SOF13", "Differential sequential DCT (AC)", SOF), 0xFFCE: ("SOF14", "Differential progressive DCT (AC)", SOF), 0xFFCF: ("SOF15", "Differential spatial (AC)", SOF), 0xFFD0: ("RST0", "Restart 0", None), 0xFFD1: ("RST1", "Restart 1", None), 0xFFD2: ("RST2", "Restart 2", None), 0xFFD3: ("RST3", "Restart 3", None), 0xFFD4: ("RST4", "Restart 4", None), 0xFFD5: ("RST5", "Restart 5", None), 0xFFD6: ("RST6", "Restart 6", None), 0xFFD7: ("RST7", "Restart 7", None), 0xFFD8: ("SOI", "Start of image", None), 0xFFD9: ("EOI", "End of image", None), 0xFFDA: ("SOS", "Start of scan", Skip), 0xFFDB: ("DQT", "Define quantization table", DQT), 0xFFDC: ("DNL", "Define number of lines", Skip), 0xFFDD: ("DRI", "Define restart interval", Skip), 0xFFDE: ("DHP", "Define hierarchical progression", SOF), 0xFFDF: ("EXP", "Expand reference component", Skip), 0xFFE0: ("APP0", "Application segment 0", APP), 0xFFE1: ("APP1", "Application segment 1", APP), 0xFFE2: ("APP2", "Application segment 2", APP), 0xFFE3: ("APP3", "Application segment 3", APP), 0xFFE4: ("APP4", "Application segment 4", APP), 0xFFE5: ("APP5", "Application segment 5", APP), 0xFFE6: ("APP6", "Application segment 6", APP), 0xFFE7: ("APP7", "Application segment 7", APP), 0xFFE8: ("APP8", "Application segment 8", APP), 0xFFE9: ("APP9", "Application segment 9", APP), 0xFFEA: ("APP10", "Application segment 10", APP), 0xFFEB: ("APP11", "Application segment 11", APP), 0xFFEC: ("APP12", "Application segment 12", APP), 0xFFED: ("APP13", "Application segment 13", APP), 0xFFEE: ("APP14", "Application segment 14", APP), 0xFFEF: ("APP15", "Application segment 15", APP), 0xFFF0: ("JPG0", "Extension 0", None), 0xFFF1: ("JPG1", "Extension 1", None), 0xFFF2: ("JPG2", "Extension 2", None), 0xFFF3: ("JPG3", "Extension 3", None), 0xFFF4: ("JPG4", "Extension 4", None), 0xFFF5: ("JPG5", "Extension 5", None), 0xFFF6: ("JPG6", "Extension 6", None), 0xFFF7: ("JPG7", "Extension 7", None), 0xFFF8: ("JPG8", "Extension 8", None), 0xFFF9: ("JPG9", "Extension 9", None), 0xFFFA: ("JPG10", "Extension 10", None), 0xFFFB: ("JPG11", "Extension 11", None), 0xFFFC: ("JPG12", "Extension 12", None), 0xFFFD: ("JPG13", "Extension 13", None), 0xFFFE: ("COM", "Comment", COM), } def _accept(prefix): # Magic number was taken from https://en.wikipedia.org/wiki/JPEG return prefix[:3] == b"\xFF\xD8\xFF" ## # Image plugin for JPEG and JFIF images.
[docs]class JpegImageFile(ImageFile.ImageFile): format = "JPEG" format_description = "JPEG (ISO 10918)" def _open(self): s = self.fp.read(3) if not _accept(s): msg = "not a JPEG file" raise SyntaxError(msg) s = b"\xFF" # Create attributes self.bits = self.layers = 0 # JPEG specifics (internal) self.layer = [] self.huffman_dc = {} self.huffman_ac = {} self.quantization = {} self.app = {} # compatibility self.applist = [] self.icclist = [] while True: i = s[0] if i == 0xFF: s = s + self.fp.read(1) i = i16(s) else: # Skip non-0xFF junk s = self.fp.read(1) continue if i in MARKER: name, description, handler = MARKER[i] if handler is not None: handler(self, i) if i == 0xFFDA: # start of scan rawmode = self.mode if self.mode == "CMYK": rawmode = "CMYK;I" # assume adobe conventions self.tile = [("jpeg", (0, 0) + self.size, 0, (rawmode, ""))] # self.__offset = self.fp.tell() break s = self.fp.read(1) elif i == 0 or i == 0xFFFF: # padded marker or junk; move on s = b"\xff" elif i == 0xFF00: # Skip extraneous data (escaped 0xFF) s = self.fp.read(1) else: msg = "no marker found" raise SyntaxError(msg)
[docs] def load_read(self, read_bytes): """ internal: read more image data For premature EOF and LOAD_TRUNCATED_IMAGES adds EOI marker so libjpeg can finish decoding """ s = self.fp.read(read_bytes) if not s and ImageFile.LOAD_TRUNCATED_IMAGES and not hasattr(self, "_ended"): # Premature EOF. # Pretend file is finished adding EOI marker self._ended = True return b"\xFF\xD9" return s
[docs] def draft(self, mode, size): if len(self.tile) != 1: return # Protect from second call if self.decoderconfig: return d, e, o, a = self.tile[0] scale = 1 original_size = self.size if a[0] == "RGB" and mode in ["L", "YCbCr"]: self.mode = mode a = mode, "" if size: scale = min(self.size[0] // size[0], self.size[1] // size[1]) for s in [8, 4, 2, 1]: if scale >= s: break e = ( e[0], e[1], (e[2] - e[0] + s - 1) // s + e[0], (e[3] - e[1] + s - 1) // s + e[1], ) self._size = ((self.size[0] + s - 1) // s, (self.size[1] + s - 1) // s) scale = s self.tile = [(d, e, o, a)] self.decoderconfig = (scale, 0) box = (0, 0, original_size[0] / scale, original_size[1] / scale) return self.mode, box
[docs] def load_djpeg(self): # ALTERNATIVE: handle JPEGs via the IJG command line utilities f, path = tempfile.mkstemp() os.close(f) if os.path.exists(self.filename): subprocess.check_call(["djpeg", "-outfile", path, self.filename]) else: msg = "Invalid Filename" raise ValueError(msg) try: with Image.open(path) as _im: _im.load() self.im = _im.im finally: try: os.unlink(path) except OSError: pass self.mode = self.im.mode self._size = self.im.size self.tile = []
def _getexif(self): return _getexif(self) def _getmp(self): return _getmp(self)
[docs] def getxmp(self): """ Returns a dictionary containing the XMP tags. Requires defusedxml to be installed. :returns: XMP tags in a dictionary. """ for segment, content in self.applist: if segment == "APP1": marker, xmp_tags = content.rsplit(b"\x00", 1) if marker == b"http://ns.adobe.com/xap/1.0/": return self._getxmp(xmp_tags) return {}
def _getexif(self): if "exif" not in self.info: return None return self.getexif()._get_merged_dict() def _getmp(self): # Extract MP information. This method was inspired by the "highly # experimental" _getexif version that's been in use for years now, # itself based on the ImageFileDirectory class in the TIFF plugin. # The MP record essentially consists of a TIFF file embedded in a JPEG # application marker. try: data = self.info["mp"] except KeyError: return None file_contents = io.BytesIO(data) head = file_contents.read(8) endianness = ">" if head[:4] == b"\x4d\x4d\x00\x2a" else "<" # process dictionary try: info = TiffImagePlugin.ImageFileDirectory_v2(head) file_contents.seek(info.next) info.load(file_contents) mp = dict(info) except Exception as e: msg = "malformed MP Index (unreadable directory)" raise SyntaxError(msg) from e # it's an error not to have a number of images try: quant = mp[0xB001] except KeyError as e: msg = "malformed MP Index (no number of images)" raise SyntaxError(msg) from e # get MP entries mpentries = [] try: rawmpentries = mp[0xB002] for entrynum in range(0, quant): unpackedentry = struct.unpack_from( f"{endianness}LLLHH", rawmpentries, entrynum * 16 ) labels = ("Attribute", "Size", "DataOffset", "EntryNo1", "EntryNo2") mpentry = dict(zip(labels, unpackedentry)) mpentryattr = { "DependentParentImageFlag": bool(mpentry["Attribute"] & (1 << 31)), "DependentChildImageFlag": bool(mpentry["Attribute"] & (1 << 30)), "RepresentativeImageFlag": bool(mpentry["Attribute"] & (1 << 29)), "Reserved": (mpentry["Attribute"] & (3 << 27)) >> 27, "ImageDataFormat": (mpentry["Attribute"] & (7 << 24)) >> 24, "MPType": mpentry["Attribute"] & 0x00FFFFFF, } if mpentryattr["ImageDataFormat"] == 0: mpentryattr["ImageDataFormat"] = "JPEG" else: msg = "unsupported picture format in MPO" raise SyntaxError(msg) mptypemap = { 0x000000: "Undefined", 0x010001: "Large Thumbnail (VGA Equivalent)", 0x010002: "Large Thumbnail (Full HD Equivalent)", 0x020001: "Multi-Frame Image (Panorama)", 0x020002: "Multi-Frame Image: (Disparity)", 0x020003: "Multi-Frame Image: (Multi-Angle)", 0x030000: "Baseline MP Primary Image", } mpentryattr["MPType"] = mptypemap.get(mpentryattr["MPType"], "Unknown") mpentry["Attribute"] = mpentryattr mpentries.append(mpentry) mp[0xB002] = mpentries except KeyError as e: msg = "malformed MP Index (bad MP Entry)" raise SyntaxError(msg) from e # Next we should try and parse the individual image unique ID list; # we don't because I've never seen this actually used in a real MPO # file and so can't test it. return mp # -------------------------------------------------------------------- # stuff to save JPEG files RAWMODE = { "1": "L", "L": "L", "RGB": "RGB", "RGBX": "RGB", "CMYK": "CMYK;I", # assume adobe conventions "YCbCr": "YCbCr", } # fmt: off zigzag_index = ( 0, 1, 5, 6, 14, 15, 27, 28, 2, 4, 7, 13, 16, 26, 29, 42, 3, 8, 12, 17, 25, 30, 41, 43, 9, 11, 18, 24, 31, 40, 44, 53, 10, 19, 23, 32, 39, 45, 52, 54, 20, 22, 33, 38, 46, 51, 55, 60, 21, 34, 37, 47, 50, 56, 59, 61, 35, 36, 48, 49, 57, 58, 62, 63, ) samplings = { (1, 1, 1, 1, 1, 1): 0, (2, 1, 1, 1, 1, 1): 1, (2, 2, 1, 1, 1, 1): 2, } # fmt: on
[docs]def convert_dict_qtables(qtables): deprecate("convert_dict_qtables", 10, action="Conversion is no longer needed") return qtables
[docs]def get_sampling(im): # There's no subsampling when images have only 1 layer # (grayscale images) or when they are CMYK (4 layers), # so set subsampling to the default value. # # NOTE: currently Pillow can't encode JPEG to YCCK format. # If YCCK support is added in the future, subsampling code will have # to be updated (here and in JpegEncode.c) to deal with 4 layers. if not hasattr(im, "layers") or im.layers in (1, 4): return -1 sampling = im.layer[0][1:3] + im.layer[1][1:3] + im.layer[2][1:3] return samplings.get(sampling, -1)
def _save(im, fp, filename): if im.width == 0 or im.height == 0: msg = "cannot write empty image as JPEG" raise ValueError(msg) try: rawmode = RAWMODE[im.mode] except KeyError as e: msg = f"cannot write mode {im.mode} as JPEG" raise OSError(msg) from e info = im.encoderinfo dpi = [round(x) for x in info.get("dpi", (0, 0))] quality = info.get("quality", -1) subsampling = info.get("subsampling", -1) qtables = info.get("qtables") if quality == "keep": quality = -1 subsampling = "keep" qtables = "keep" elif quality in presets: preset = presets[quality] quality = -1 subsampling = preset.get("subsampling", -1) qtables = preset.get("quantization") elif not isinstance(quality, int): msg = "Invalid quality setting" raise ValueError(msg) else: if subsampling in presets: subsampling = presets[subsampling].get("subsampling", -1) if isinstance(qtables, str) and qtables in presets: qtables = presets[qtables].get("quantization") if subsampling == "4:4:4": subsampling = 0 elif subsampling == "4:2:2": subsampling = 1 elif subsampling == "4:2:0": subsampling = 2 elif subsampling == "4:1:1": # For compatibility. Before Pillow 4.3, 4:1:1 actually meant 4:2:0. # Set 4:2:0 if someone is still using that value. subsampling = 2 elif subsampling == "keep": if im.format != "JPEG": msg = "Cannot use 'keep' when original image is not a JPEG" raise ValueError(msg) subsampling = get_sampling(im) def validate_qtables(qtables): if qtables is None: return qtables if isinstance(qtables, str): try: lines = [ int(num) for line in qtables.splitlines() for num in line.split("#", 1)[0].split() ] except ValueError as e: msg = "Invalid quantization table" raise ValueError(msg) from e else: qtables = [lines[s : s + 64] for s in range(0, len(lines), 64)] if isinstance(qtables, (tuple, list, dict)): if isinstance(qtables, dict): qtables = [ qtables[key] for key in range(len(qtables)) if key in qtables ] elif isinstance(qtables, tuple): qtables = list(qtables) if not (0 < len(qtables) < 5): msg = "None or too many quantization tables" raise ValueError(msg) for idx, table in enumerate(qtables): try: if len(table) != 64: raise TypeError table = array.array("H", table) except TypeError as e: msg = "Invalid quantization table" raise ValueError(msg) from e else: qtables[idx] = list(table) return qtables if qtables == "keep": if im.format != "JPEG": msg = "Cannot use 'keep' when original image is not a JPEG" raise ValueError(msg) qtables = getattr(im, "quantization", None) qtables = validate_qtables(qtables) extra = info.get("extra", b"") icc_profile = info.get("icc_profile") if icc_profile: ICC_OVERHEAD_LEN = 14 MAX_BYTES_IN_MARKER = 65533 MAX_DATA_BYTES_IN_MARKER = MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN markers = [] while icc_profile: markers.append(icc_profile[:MAX_DATA_BYTES_IN_MARKER]) icc_profile = icc_profile[MAX_DATA_BYTES_IN_MARKER:] i = 1 for marker in markers: size = o16(2 + ICC_OVERHEAD_LEN + len(marker)) extra += ( b"\xFF\xE2" + size + b"ICC_PROFILE\0" + o8(i) + o8(len(markers)) + marker ) i += 1 comment = info.get("comment", im.info.get("comment")) # "progressive" is the official name, but older documentation # says "progression" # FIXME: issue a warning if the wrong form is used (post-1.1.7) progressive = info.get("progressive", False) or info.get("progression", False) optimize = info.get("optimize", False) exif = info.get("exif", b"") if isinstance(exif, Image.Exif): exif = exif.tobytes() # get keyword arguments im.encoderconfig = ( quality, progressive, info.get("smooth", 0), optimize, info.get("streamtype", 0), dpi[0], dpi[1], subsampling, qtables, comment, extra, exif, ) # if we optimize, libjpeg needs a buffer big enough to hold the whole image # in a shot. Guessing on the size, at im.size bytes. (raw pixel size is # channels*size, this is a value that's been used in a django patch. # https://github.com/matthewwithanm/django-imagekit/issues/50 bufsize = 0 if optimize or progressive: # CMYK can be bigger if im.mode == "CMYK": bufsize = 4 * im.size[0] * im.size[1] # keep sets quality to -1, but the actual value may be high. elif quality >= 95 or quality == -1: bufsize = 2 * im.size[0] * im.size[1] else: bufsize = im.size[0] * im.size[1] # The EXIF info needs to be written as one block, + APP1, + one spare byte. # Ensure that our buffer is big enough. Same with the icc_profile block. bufsize = max(ImageFile.MAXBLOCK, bufsize, len(exif) + 5, len(extra) + 1) ImageFile._save(im, fp, [("jpeg", (0, 0) + im.size, 0, rawmode)], bufsize) def _save_cjpeg(im, fp, filename): # ALTERNATIVE: handle JPEGs via the IJG command line utilities. tempfile = im._dump() subprocess.check_call(["cjpeg", "-outfile", filename, tempfile]) try: os.unlink(tempfile) except OSError: pass ## # Factory for making JPEG and MPO instances
[docs]def jpeg_factory(fp=None, filename=None): im = JpegImageFile(fp, filename) try: mpheader = im._getmp() if mpheader[45057] > 1: # It's actually an MPO from .MpoImagePlugin import MpoImageFile # Don't reload everything, just convert it. im = MpoImageFile.adopt(im, mpheader) except (TypeError, IndexError): # It is really a JPEG pass except SyntaxError: warnings.warn( "Image appears to be a malformed MPO file, it will be " "interpreted as a base JPEG file" ) return im
# --------------------------------------------------------------------- # Registry stuff Image.register_open(JpegImageFile.format, jpeg_factory, _accept) Image.register_save(JpegImageFile.format, _save) Image.register_extensions(JpegImageFile.format, [".jfif", ".jpe", ".jpg", ".jpeg"]) Image.register_mime(JpegImageFile.format, "image/jpeg")