Is the 2nd and 3rd byte of a JPEG image always the APP0 or APP1 marker?

Question

I have a few different JPEG images I\'ve been testing with. As far as I\'ve seen the 0th and first bytes are always 0xFF and 0xD8.

The s

Answer 1

No. There are programs that remove some markers. ImageOptim is such a program. You only need some of the markers. This program will also optimise the huffman tables