4

JPEG has many Marker Segment Levels, I want to read and write Comment marker segment level - COM (read/write). It needs low level programming. How can i access it in iOS ?

References -

  1. http://help.accusoft.com/ImageGear/v18.1/Mac/IGDLL-10-05.html
  2. https://www.npmjs.com/package/jpeg-com-segment
  3. http://www.sno.phy.queensu.ca/~phil/exiftool/
vikas prajapati
  • 1,868
  • 2
  • 18
  • 26
Meet
  • 609
  • 6
  • 10

1 Answers1

1

IOS allows you to open files. Read the JPEG file. Search the stream for the COM marker. Read the length. Read the data. It's basic [objective] C programming.

user3344003
  • 20,574
  • 3
  • 26
  • 62
  • I don't have code for it. Anyone could write it and it is simple to do. The only trick is that the length is is Bigendian format so the two bytes have to be reversed on some processors (e.g. Intel). – user3344003 Apr 25 '17 at 13:56
  • @user3344003 Hello. I have image with no COM maker. I want to add first COM marker. Do you know on which position or index i need to add my comment data? – Meet May 10 '17 at 05:23