I have created a content text file named for a keyword I want to use in building backlinks. This content file gets embedded into a .jpg image, the image also is appropriately named after the same keyword. When crawled, the image data is machine language but the compressed text file stands out as my "keyword". Although I left no html code for the moderator to ban me my keyword passed.

It's called Steganography: hiding/embedding text within image.
The crawlers will get image, image title and image alt, not the text inside the image.

And what is your question?