Python读取图片属性信息的实现方法

# -*- coding:utf-8 -*-import binasciiclass ParseMethod(object):  @staticmethod  def parse_default(f, count, offset):    pass  @staticmethod  def parse_latitude(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    latitude = [0,0,0]    for i in xrange(count):      byte = f.read(4)      numerator = byte.encode('hex')      byte = f.read(4)      denominator = byte.encode('hex')      latitude[i] = float(int(numerator, 16)) / int(denominator, 16)    print 'Latitude:/t%.2f %.2f/' %.2f/"' % (latitude[0], latitude[1], latitude[2])    f.seek(old_pos)    @staticmethod  def parse_longtitude(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    longtitude = [0,0,0]    for i in xrange(count):      byte = f.read(4)      numerator = byte.encode('hex')      byte = f.read(4)      denominator = byte.encode('hex')      longtitude[i] = float(int(numerator, 16)) / int(denominator, 16)    print 'Longtitude:/t%.2f %.2f/' %.2f/"' % (longtitude[0], longtitude[1], longtitude[2])    f.seek(old_pos)   @staticmethod  def parse_make(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(count)    a = byte.encode('hex')    print 'Make:/t/t' + binascii.a2b_hex(a)    f.seek(old_pos)   @staticmethod  def parse_model(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(count)    a = byte.encode('hex')    print 'Model:/t/t' + binascii.a2b_hex(a)    f.seek(old_pos)       @staticmethod  def parse_datetime(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(count)    a = byte.encode('hex')    print 'DateTime:/t' + binascii.a2b_hex(a)    f.seek(old_pos)  # rational data type, 05  @staticmethod  def parse_xresolution(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(4)    numerator = byte.encode('hex')    byte = f.read(4)    denominator = byte.encode('hex')    xre = int(numerator, 16) / int(denominator, 16)    print 'XResolution:/t' + str(xre) + ' dpi'    f.seek(old_pos)  @staticmethod  def parse_yresolution(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(4)    numerator = byte.encode('hex')    byte = f.read(4)    denominator = byte.encode('hex')    xre = int(numerator, 16) / int(denominator, 16)    print 'YResolution:/t' + str(xre) + ' dpi'    f.seek(old_pos)  @staticmethod  def parse_exif_ifd(f, count, offset):    old_pos = f.tell()    f.seek(12 + offset)    byte = f.read(2)    a = byte.encode('hex')        exif_ifd_number = int(a, 16)    for i in xrange(exif_ifd_number):      byte = f.read(2)      tag_id = byte.encode('hex')      #print tag_id,      byte = f.read(2)      type_n = byte.encode('hex')      #print type_n,      byte = f.read(4)      count = byte.encode('hex')      #print count,      byte = f.read(4)      value_offset = byte.encode('hex')      #print value_offset      value_offset = int(value_offset, 16)      EXIF_IFD_DICT.get(tag_id, ParseMethod.parse_default)(f, count, value_offset)    f.seek(old_pos)    @staticmethod  def parse_x_pixel(f, count, value):    print 'X Pixels:/t' + str(value)  @staticmethod  def parse_y_pixel(f, count, value):    print 'y Pixels:/t' + str(value)  @staticmethod  def parse_gps_ifd(f, count, offset):    old_pos = f.tell()        f.seek(12 + offset)    byte = f.read(2)    a = byte.encode('hex')      gps_ifd_number = int(a, 16)    for i in xrange(gps_ifd_number):      byte = f.read(2)      tag_id = byte.encode('hex')      #print tag_id,      byte = f.read(2)      type_n = byte.encode('hex')      #print type_n,      byte = f.read(4)      count = byte.encode('hex')      #print count,      byte = f.read(4)      value_offset = byte.encode('hex')      #print value_offset      count = int(count, 16)      value_offset = int(value_offset, 16)      GPS_IFD_DICT.get(tag_id, ParseMethod.parse_default)(f, count, value_offset)    f.seek(old_pos) IFD_dict = {  '010f' : ParseMethod.parse_make ,  '0110' : ParseMethod.parse_model ,  '0132' : ParseMethod.parse_datetime ,  '011a' : ParseMethod.parse_xresolution ,  '011b' : ParseMethod.parse_yresolution ,  '8769' : ParseMethod.parse_exif_ifd ,  '8825' : ParseMethod.parse_gps_ifd}EXIF_IFD_DICT = {  'a002' : ParseMethod.parse_x_pixel ,  'a003' : ParseMethod.parse_y_pixel}GPS_IFD_DICT = {  '0002' : ParseMethod.parse_latitude ,  '0004' : ParseMethod.parse_longtitude}with open('image.jpg', 'rb') as f:  byte = f.read(2)  a = byte.encode('hex')  print 'SOI Marker:/t' + a  byte = f.read(2)  a = byte.encode('hex')  print 'APP1 Marker:/t' + a  byte = f.read(2)  a = byte.encode('hex')  print 'APP1 Length:/t' + str(int(a, 16)) + ' .Dec'  byte = f.read(4)  a = byte.encode('hex')  print 'Identifier:/t' + binascii.a2b_hex(a)  byte = f.read(2)  a = byte.encode('hex')  print 'Pad:/t/t' + a   print   print 'Begin to print Header.... '  print 'APP1 Body: '  byte = f.read(2)  a = byte.encode('hex')  print 'Byte Order:/t' + a    byte = f.read(2)  a = byte.encode('hex')  print '42:/t/t' + a   byte = f.read(4)  a = byte.encode('hex')  print '0th IFD Offset:/t' + a   print 'Finish print Header'  print 'Begin to print 0th IFD....'  print  #print 'Total: ',  byte = f.read(2)  a = byte.encode('hex')  interoperability_number = int(a, 16)  #print interoperability_number  for i in xrange(interoperability_number):    byte = f.read(2)    tag_id = byte.encode('hex')    #print tag_id,    byte = f.read(2)    type_n = byte.encode('hex')    #print type_n,    byte = f.read(4)    count = byte.encode('hex')    #print count,    byte = f.read(4)    value_offset = byte.encode('hex')    #print value_offset    count = int(count, 16)    value_offset = int(value_offset, 16)    # simulate switch    IFD_dict.get(tag_id, ParseMethod.parse_default)(f, count, value_offset)  print  print 'Finish print 0th IFD....'