JezK
Edit File: imghdr.py
"""Recognize image file formats based on their first few bytes.""" __all__ = ["what"] #-------------------------# # Recognize image headers # #-------------------------# def what(file, h=None): f = None try: if h is None: if isinstance(file, basestring): f = open(file, 'rb') h = f.read(32) else: location = file.tell() h = file.read(32) file.seek(location) for tf in tests: res = tf(h, f) if res: return res finally: if f: f.close() return None #---------------------------------# # Subroutines per image file type # #---------------------------------# tests = [] def test_jpeg(h, f): """JPEG data in JFIF format""" if h[6:10] == 'JFIF': return 'jpeg' tests.append(test_jpeg) def test_exif(h, f): """JPEG data in Exif format""" if h[6:10] == 'Exif': return 'jpeg' tests.append(test_exif) def test_png(h, f): if h[:8] == "\211PNG\r\n\032\n": return 'png' tests.append(test_png) def test_gif(h, f): """GIF ('87 and '89 variants)""" if h[:6] in ('GIF87a', 'GIF89a'): return 'gif' tests.append(test_gif) def test_tiff(h, f): """TIFF (can be in Motorola or Intel byte order)""" if h[:2] in ('MM', 'II'): return 'tiff' tests.append(test_tiff) def test_rgb(h, f): """SGI image library""" if h[:2] == '\001\332': return 'rgb' tests.append(test_rgb) def test_pbm(h, f): """PBM (portable bitmap)""" if len(h) >= 3 and \ h[0] == 'P' and h[1] in '14' and h[2] in ' \t\n\r': return 'pbm' tests.append(test_pbm) def test_pgm(h, f): """PGM (portable graymap)""" if len(h) >= 3 and \ h[0] == 'P' and h[1] in '25' and h[2] in ' \t\n\r': return 'pgm' tests.append(test_pgm) def test_ppm(h, f): """PPM (portable pixmap)""" if len(h) >= 3 and \ h[0] == 'P' and h[1] in '36' and h[2] in ' \t\n\r': return 'ppm' tests.append(test_ppm) def test_rast(h, f): """Sun raster file""" if h[:4] == '\x59\xA6\x6A\x95': return 'rast' tests.append(test_rast) def test_xbm(h, f): """X bitmap (X10 or X11)""" s = '#define ' if h[:len(s)] == s: return 'xbm' tests.append(test_xbm) def test_bmp(h, f): if h[:2] == 'BM': return 'bmp' tests.append(test_bmp) #--------------------# # Small test program # #--------------------# def test(): import sys recursive = 0 if sys.argv[1:] and sys.argv[1] == '-r': del sys.argv[1:2] recursive = 1 try: if sys.argv[1:]: testall(sys.argv[1:], recursive, 1) else: testall(['.'], recursive, 1) except KeyboardInterrupt: sys.stderr.write('\n[Interrupted]\n') sys.exit(1) def testall(list, recursive, toplevel): import sys import os for filename in list: if os.path.isdir(filename): print filename + '/:', if recursive or toplevel: print 'recursing down:' import glob names = glob.glob(os.path.join(filename, '*')) testall(names, recursive, 0) else: print '*** directory (use -r) ***' else: print filename + ':', sys.stdout.flush() try: print what(filename) except IOError: print '*** not found ***'