How to get raw jpeg data (but no metatags / proprietary markers)
- by CoolAJ86
I want to get raw jpeg data - no metadata.
I'm very confused looking at the jpeg "standards".
How correct is my understanding of the marker "tree"?
0xFFD8 - Identifies the file as an image
0xFFE? - EXIF, JFIF, SPIFF, ICC, etc
0x???? - the length of the tag
0xFFD8 - Start of Image
0xFFE0 - should follow SOI as per spec, but often preceded by comments ???
0x???? - Matrices, tags, random data ???
There are never other markers in-between these markers?
Or these include the matrices and such?
0xFFDA - Start of Stream - This is what I want, yes?
0xXXXX - length of stream
0xFFD9 - End of Stream (EOI)
0x???? - Comment tags, extra exif, jfif info???
0xFFD9 - End of Image
0xFF00 - escaped 0xFF, not to be confused with a marker
This has been my reading material:
http://en.wikipedia.org/wiki/JPEG
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html
http://www.media.mit.edu/pia/Research/deepview/exif.html
http://www.faqs.org/faqs/jpeg-faq/part1/section-15.html