getjpggeom.py

   1 #!/usr/bin/python
   2 import struct
   3
   4 def get_jpeg_geometory(filename):
   5     jpeg = open(filename, 'r')
   6     jpeg.read(2)
   7     b = jpeg.read(1)
   8     try:
   9         while (b and ord(b) != 0xDA):
  10             while (ord(b) != 0xFF): b = jpeg.read(1)
  11             while (ord(b) == 0xFF): b = jpeg.read(1)
  12             if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
  13                 jpeg.read(3)
  14                 h, w = struct.unpack(">HH", jpeg.read(4))
  15                 break
  16             else:
  17                 jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0])-2)
  18             b = jpeg.read(1)
  19         width = int(w)
  20         height = int(h)
  21         return (width, height)
  22     except struct.error:
  23         return (None, None)
  24     except ValueError:
  25         return (None, None)
  26
  27 if __name__ == '__main__':
  28     pass
  29 #(w, h) = get_jpeg_geometory('test.jpg')
  30 #print w, h
  31
  32