$  file sample.jpg
sample.jpg: JPEG image data, JFIF standard 1.01, resolution (DPI), density 123x123, segment length 16, progressive, precision 8, 1024x1448, frames 3
$ perl -v
This is perl 5, version 22, subversion 1 (v5.22.1) built for darwin-thread-multi-2level

$ hexdump -C sample.jpg | head -30
00000000  ff d8 ff e0 00 10 4a 46  49 46 00 01 01 01 00 7b  |......JFIF.....{|
00000010  00 7b 00 00 ff db 00 43  00 01 01 01 01 01 01 01  |.{.....C........|
00000020  01 01 01 01 01 01 01 01  01 01 01 01 01 01 01 01  |................|*
00000090  01 01 01 01 01 01 01 01  01 01 01 01 01 01 >>>> ff c2 <<<<   |................|
000000a0  00 11 08 >>> 05 a8 04 00 <<<< 03  01 22 00 02 11 01 03 11  |........."......|
000000b0  01 ff c4 00 1e 00 01 00  01 04 03 01 01 00 00 00  |................|
000000c0  00 00 00 00 00 00 00 06  05 07 08 09 03 04 0a 02  |................|