When compressing, you always are using the source image in some sense. What you end up with could be a fairly minimal way to represent the image. Though yes,

When compressing, you always are using the source image in some sense. What you end up with could be a fairly minimal way to represent the image. Though yes, clearly, the amount of processing required to reach that compression is absurd. But then, most ultra-efficient compression algorithms have this problem at least initially.