Implementation method of reading image attribute information in Python

This article uses a Python script to read image information. There are several instructions as follows:

1. Error handling is not implemented

2. All information is not read, probably only GPS information, Picture resolution, picture pixels, equipment manufacturer, shooting equipment, etc.

3. After simple modification, it should be possible to violently modify the GPS information of the picture

4. But for pictures that do not have GPS information themselves, The implementation is very complex and requires careful calculation of the offset of each descriptor.

After the script is run, the reading results are as follows

View here and Windows properties The content read by the device is exactly the same

The source code is as follows

# -*- 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....'

Summary

The implementation method of using Python to read image attribute information is here That’s basically it. Has everyone learned the lesson? I hope this article will bring some help to everyone's study or work.

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