This is the traditional model of academic publishing that was driven by the limited communication and collaboration ability of the time. A study like the one you describe would be done by multiple co-authors (I don't think I've written an image processing paper that doesn't have at least three people as authors, all of whom actually contributed to the work one way or another.)
Furthermore, the traditional paper would have to make a lot of guesses about the kinds of images people were likely interested in and the range of characteristics that mattered. What kind of noise spectrum due your images have, how does increasing contrast affect things, what about the spacial frequency distribution in the images themselves, and so on... Different fields have radically different "typical" images and the attempts at covering a reasonable range of the in traditional papers were not necessarily very limited.
Instead, I see this model of publication as exploiting the possibilities of the 'Net to allow more effective communication and collaboration. And it is publication: it is making public, which is what makes the difference between science and alchemy... if there had been a "Proceedings of the Alchemical Society" we'd have had chemistry a thousand years ago.
What this model of publication does not (yet) have is a reputation mechanism, but it isn't clear it needs one, because you can see the results (and the code) for yourself. As such, I think the author has not only done something interesting in the image compression space, they are pointing the way on the future of scientific publication.
Measuring this model as if it could be described as a certain amount of progress along a line toward the old endpoint is mistaken. This is a paradigm shift, and the models are incommensurable.
