I agree about JPEG, if you load in a previously saved jpeg and save it again at any level of accuracy it will still lose some more quality. If you need to be loading in image again and again and making modifications you should save it as a PNG or something and use that to work from.
You can probably find out the compression level of a jpeg fairly easily by finding the definition of the file format and writing a simple parser.
You can probably find out the compression level of a jpeg fairly easily by finding the definition of the file format and writing a simple parser.