Hex format of JPEG, can image end ffd9 be in 9 and a columns

Question

For solving some problems in steganography, I need to look for end of images in hex

I am using

xxd image.jpeg|grep ffd9

it does return the line having ffd9 when it is in C and D columns

but the same does not return anything when it is in 9 and A columns

Answer 1

With GNU grep this will give you the byte-offsets of the EOI markers:

LC_ALL=C grep -oabUP "\xFF\xD9" image.jpeg

For reference:

• bytes 0xFF, 0xD8 indicate start of image (SOI)
• bytes 0xFF, 0xD9 indicate end of image (EOI)