What do I look at when I view a JPG image in a text editor?

Question

I am not knowledgeable of Image file formats or even compression. I opened up a JPG image file in a text editor and I saw gibberish. Not zero and one gibberish. Or even numbers from 0 to 256 gibberish. I saw so many different characters. To name a few: ¡jÑœ¥îŸàöÐʽì™ÑOø~w;6Œb¿àºVËwÿ ö

Do I see these characters instead of integers because the JPG format is compressed and I am not reading bits per pixel when I look at a JPG? Also, how many characters are available for writing in a JPG file? Is it all available ASCII characters?

Answer 1

The JPEG file format is a binary file format. There is no reason for you to see numbers, since in binary numbers are encoded using the entire character set (in fact, for JPEG the character 0xFF is special). Numbers in JPEG are further encoded using Huffman encoding, which means that more than one number is encoded per character. But even without Huffman encoding you wouldn't see numbers encoded textually.