Python读取图片属性信息的实现方法

本文是利用Python脚本读取图片信息，有几个说明如下：

 1、没有实现错误处理

 2、没有读取所有信息，大概只有 GPS 信息、图片分辨率、图片像素、设备商、拍摄设备等

 3、简单修改后应该能实现暴力修改图片的 GPS 信息

 4、但对于本身没有 GPS 信息的图片，实现则非常复杂，需要仔细计算每个描述符的偏移量

脚本运行后，读取结果如下

脚本读取的信息

这里和 Windows 属性查看器读到的内容完全一致

图片信息1

图片信息2

源码如下

    # -*- coding:utf-8 -*-
    import binascii

    class 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....'

总结

利用Python读取图片属性信息的实现方法到这就基本结束了，大家都学会了吗？希望这篇文章对大家的学习或者工作带来一定的帮助，