i think it is possible , i can share with you the image converter i am currently using. it can do pdf to html conversion. i am not an expert in this field so thew only way i know is to employ an image converter. i have looked for solutions in many forums but i can't find a way which can do it by myself. so if you haven't found a good way to do that, you can have a try.
Yes this is possible, and will not be fun to do in php.
But here are the concepts of this:
Eventually, you can reduce your solution to be more efficient. But for now to understand the process, do this:
userUploadFile => uncompress pdf and output to temporary folder(in .txt) (also validate the file) => parse the file => output in the form you want AND delete temporary file