File Content: imagesize.py import io import os import re import struct from xml.etree import ElementTree _UNIT_KM = -3 _UNIT_100M = -2 _UNIT_10M = -1 _UNIT_1M = 0 _UNIT_10CM = 1 _UNIT_CM = 2 _UNIT_MM = 3 _UNIT_0_1MM = 4 _UNIT_0_01MM = 5 _UNIT_UM = 6 _UNIT_INCH = 6 _TIFF_TYPE_SIZES = { 1: 1, 2: 1, 3: 2, 4: 4, 5: 8, 6: 1, 7: 1, 8: 2, 9: 4, 10: 8, 11: 4, 12: 8, } def _convertToDPI(density, unit): if unit == _UNIT_KM: return int(density * 0.0000254 + 0.5) elif unit == _UNIT_100M: return int(density * 0.000254 + 0.5) elif unit == _UNIT_10M: return int(density * 0.00254 + 0.5) elif unit == _UNIT_1M: return int(density * 0.0254 + 0.5) elif unit == _UNIT_10CM: return int(density * 0.254 + 0.5) elif unit == _UNIT_CM: return int(density * 2.54 + 0.5) elif unit == _UNIT_MM: return int(density * 25.4 + 0.5) elif unit == _UNIT_0_1MM: return density * 254 elif unit == _UNIT_0_01MM: return density * 2540 elif unit == _UNIT_UM: return density * 25400 return density def _convertToPx(value): matched = re.match(r"(\d+(?:\.\d+)?)?([a-z]*)$", value) if not matched: raise ValueError("unknown length value: %s" % value) length, unit = matched.groups() if unit == "": return float(length) elif unit == "cm": return float(length) * 96 / 2.54 elif unit == "mm": return float(length) * 96 / 2.54 / 10 elif unit == "in": return float(length) * 96 elif unit == "pc": return float(length) * 96 / 6 elif unit == "pt": return float(length) * 96 / 6 elif unit == "px": return float(length) raise ValueError("unknown unit type: %s" % unit) def get(filepath): """ Return (width, height) for a given img file content no requirements :type filepath: Union[bytes, str, pathlib.Path] :rtype Tuple[int, int] """ height = -1 width = -1 if isinstance(filepath, io.BytesIO): # file-like object fhandle = filepath else: fhandle = open(filepath, 'rb') try: head = fhandle.read(24) size = len(head) # handle GIFs if size >= 10 and head[:6] in (b'GIF87a', b'GIF89a'): # Check to see if content_type is correct try: width, height = struct.unpack("<hh", head[6:10]) except struct.error: raise ValueError("Invalid GIF file") # see png edition spec bytes are below chunk length then and finally the elif size >= 24 and head.startswith(b'\211PNG\r\n\032\n') and head[12:16] == b'IHDR': try: width, height = struct.unpack(">LL", head[16:24]) except struct.error: raise ValueError("Invalid PNG file") # Maybe this is for an older PNG version. elif size >= 16 and head.startswith(b'\211PNG\r\n\032\n'): # Check to see if we have the right content type try: width, height = struct.unpack(">LL", head[8:16]) except struct.error: raise ValueError("Invalid PNG file") # handle JPEGs elif size >= 2 and head.startswith(b'\377\330'): try: fhandle.seek(0) # Read 0xff next size = 2 ftype = 0 while not 0xc0 <= ftype <= 0xcf or ftype in [0xc4, 0xc8, 0xcc]: fhandle.seek(size, 1) byte = fhandle.read(1) while ord(byte) == 0xff: byte = fhandle.read(1) ftype = ord(byte) size = struct.unpack('>H', fhandle.read(2))[0] - 2 # We are at a SOFn block fhandle.seek(1, 1) # Skip `precision' byte. height, width = struct.unpack('>HH', fhandle.read(4)) except (struct.error, TypeError): raise ValueError("Invalid JPEG file") # handle JPEG2000s elif size >= 12 and head.startswith(b'\x00\x00\x00\x0cjP \r\n\x87\n'): fhandle.seek(48) try: height, width = struct.unpack('>LL', fhandle.read(8)) except struct.error: raise ValueError("Invalid JPEG2000 file") # handle big endian TIFF elif size >= 8 and head.startswith(b"\x4d\x4d\x00\x2a"): offset = struct.unpack('>L', head[4:8])[0] fhandle.seek(offset) ifdsize = struct.unpack(">H", fhandle.read(2))[0] for i in range(ifdsize): tag, datatype, count, data = struct.unpack(">HHLL", fhandle.read(12)) if tag == 256: if datatype == 3: width = int(data / 65536) elif datatype == 4: width = data else: raise ValueError("Invalid TIFF file: width column data type should be SHORT/LONG.") elif tag == 257: if datatype == 3: height = int(data / 65536) elif datatype == 4: height = data else: raise ValueError("Invalid TIFF file: height column data type should be SHORT/LONG.") if width != -1 and height != -1: break if width == -1 or height == -1: raise ValueError("Invalid TIFF file: width and/or height IDS entries are missing.") elif size >= 8 and head.startswith(b"\x49\x49\x2a\x00"): offset = struct.unpack('<L', head[4:8])[0] fhandle.seek(offset) ifdsize = struct.unpack("<H", fhandle.read(2))[0] for i in range(ifdsize): tag, datatype, count, data = struct.unpack("<HHLL", fhandle.read(12)) if tag == 256: width = data elif tag == 257: height = data if width != -1 and height != -1: break if width == -1 or height == -1: raise ValueError("Invalid TIFF file: width and/or height IDS entries are missing.") # handle little endian BigTiff elif size >= 8 and head.startswith(b"\x49\x49\x2b\x00"): bytesize_offset = struct.unpack('<L', head[4:8])[0] if bytesize_offset != 8: raise ValueError('Invalid BigTIFF file: Expected offset to be 8, found {} instead.'.format(offset)) offset = struct.unpack('<Q', head[8:16])[0] fhandle.seek(offset) ifdsize = struct.unpack("<Q", fhandle.read(8))[0] for i in range(ifdsize): tag, datatype, count, data = struct.unpack("<HHQQ", fhandle.read(20)) if tag == 256: width = data elif tag == 257: height = data if width != -1 and height != -1: break if width == -1 or height == -1: raise ValueError("Invalid BigTIFF file: width and/or height IDS entries are missing.") # handle SVGs elif size >= 5 and (head.startswith(b'<?xml') or head.startswith(b'<svg')): fhandle.seek(0) data = fhandle.read(1024) try: data = data.decode('utf-8') width = re.search(r'[^-]width="(.*?)"', data).group(1) height = re.search(r'[^-]height="(.*?)"', data).group(1) except Exception: raise ValueError("Invalid SVG file") width = _convertToPx(width) height = _convertToPx(height) # handle Netpbm elif head[:1] == b"P" and head[1:2] in b"123456": fhandle.seek(2) sizes = [] while True: next_chr = fhandle.read(1) if next_chr.isspace(): continue if next_chr == b"": raise ValueError("Invalid Netpbm file") if next_chr == b"#": fhandle.readline() continue if not next_chr.isdigit(): raise ValueError("Invalid character found on Netpbm file") size = next_chr next_chr = fhandle.read(1) while next_chr.isdigit(): size += next_chr next_chr = fhandle.read(1) sizes.append(int(size)) if len(sizes) == 2: break fhandle.seek(-1, os.SEEK_CUR) width, height = sizes finally: fhandle.close() return width, height def getDPI(filepath): """ Return (x DPI, y DPI) for a given img file content no requirements :type filepath: Union[bytes, str, pathlib.Path] :rtype Tuple[int, int] """ xDPI = -1 yDPI = -1 if not isinstance(filepath, bytes): filepath = str(filepath) with open(filepath, 'rb') as fhandle: head = fhandle.read(24) size = len(head) # handle GIFs # GIFs doesn't have density if size >= 10 and head[:6] in (b'GIF87a', b'GIF89a'): pass # see png edition spec bytes are below chunk length then and finally the elif size >= 24 and head.startswith(b'\211PNG\r\n\032\n'): chunkOffset = 8 chunk = head[8:] while True: chunkType = chunk[4:8] if chunkType == b'pHYs': try: xDensity, yDensity, unit = struct.unpack(">LLB", chunk[8:]) except struct.error: raise ValueError("Invalid PNG file") if unit: xDPI = _convertToDPI(xDensity, _UNIT_1M) yDPI = _convertToDPI(yDensity, _UNIT_1M) else: # no unit xDPI = xDensity yDPI = yDensity break elif chunkType == b'IDAT': break else: try: dataSize, = struct.unpack(">L", chunk[0:4]) except struct.error: raise ValueError("Invalid PNG file") chunkOffset += dataSize + 12 fhandle.seek(chunkOffset) chunk = fhandle.read(17) # handle JPEGs elif size >= 2 and head.startswith(b'\377\330'): try: fhandle.seek(0) # Read 0xff next size = 2 ftype = 0 while not 0xc0 <= ftype <= 0xcf: if ftype == 0xe0: # APP0 marker fhandle.seek(7, 1) unit, xDensity, yDensity = struct.unpack(">BHH", fhandle.read(5)) if unit == 1 or unit == 0: xDPI = xDensity yDPI = yDensity elif unit == 2: xDPI = _convertToDPI(xDensity, _UNIT_CM) yDPI = _convertToDPI(yDensity, _UNIT_CM) break fhandle.seek(size, 1) byte = fhandle.read(1) while ord(byte) == 0xff: byte = fhandle.read(1) ftype = ord(byte) size = struct.unpack('>H', fhandle.read(2))[0] - 2 except struct.error: raise ValueError("Invalid JPEG file") # handle JPEG2000s elif size >= 12 and head.startswith(b'\x00\x00\x00\x0cjP \r\n\x87\n'): fhandle.seek(32) # skip JP2 image header box headerSize = struct.unpack('>L', fhandle.read(4))[0] - 8 fhandle.seek(4, 1) foundResBox = False try: while headerSize > 0: boxHeader = fhandle.read(8) boxType = boxHeader[4:] if boxType == b'res ': # find resolution super box foundResBox = True headerSize -= 8 break boxSize, = struct.unpack('>L', boxHeader[:4]) fhandle.seek(boxSize - 8, 1) headerSize -= boxSize if foundResBox: while headerSize > 0: boxHeader = fhandle.read(8) boxType = boxHeader[4:] if boxType == b'resd': # Display resolution box yDensity, xDensity, yUnit, xUnit = struct.unpack(">HHBB", fhandle.read(10)) xDPI = _convertToDPI(xDensity, xUnit) yDPI = _convertToDPI(yDensity, yUnit) break boxSize, = struct.unpack('>L', boxHeader[:4]) fhandle.seek(boxSize - 8, 1) headerSize -= boxSize except struct.error as e: raise ValueError("Invalid JPEG2000 file") return xDPI, yDPI Submit