I'm writing this as a venue towards improved photographs, preferrably those without compression artifacts.

There are ways to compress images such that, when recreated, there is no loss, and no artifacts. While few well for graphics images, there are three that really stand out:

According to these tests, PAQ8P and STUFFIT 12.0b both enjoy a respectable 25% compression ratio, and PackJPG2.3 is close behind, at 25%.

By comparison, the next leading contender pulls in at a horrible 3.55% - might as well save the processing cycles and call it a day.

But that's compressing a JPG/JPEG image, which itself, has already been lossy compressed (resulting in a loss of data).

How are the various programs at compressing a BMP (bitmap) image?

Again, PAQ8P takes the lead at 87%, followed by STUFFIT 12.0 only half a percent behind. Surprisingly, however, about half of all programs are within 10% of that figure, and more than 4/5's are within 20% of that figure.

So what's the solution? How do we eliminate the scourage of compression artifacts? Simple - have all cameras, handheld, profession, space-born, whatever, take images and temporarily store them in bitmap format (lossless), while performing ongoing background compression (time isn't critical) to achieve a better than 7 to 1 compression for long-term storage and transmittal.

Then, use that amazing processing power of computers (workstations/desktops) everywhere, to perform on-the-fly decompression for viewing, and re-compressing for subsequent storage after image manipulation (such as cropping or adjustment of colors).

I just used PAQ8p to compress my avatar, which is already compressed as it's a gif file:

Initial size: 1,877 bytes
PAQ'd size: 35 bytes

Compression ratio: 98.135%

Then I tried it on a jpg, my Halloween avatar, which exists on my computer as a 12,458 byte jpg.

PAQ'd size: 30 bytes.
Compression ratio: 99.759%

That's lossless, folks: 0% loss.

No artifacts.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

18%?I was under the impression that this was the way things were done now, mostly. Well, maybe not 7 to 1--but that 7 to 1 is related to that special illustration, which itself is a reconstructed bitmap. Depending upon how the reconstruction went, there may not be new information and the subsequent re-compression can take advantage of that--and some programs may be more compatible with that particular type of reconstruction.

Well, hhEb09'1, there are just two forms of compression and decompression: lossless, and lossy. With the lossless variety, one can cycle a photo through a billion times and it's bit-for-bit identical to the original. With lossy, after a billion cycles, it's, well, it's visual good-for-nothing goo.

In bitmap reconstruction, pattern matching and transition algorithms are used, along with smoothing filters, in a higher resolution than the original image, in order to theoretically estimate the missing information in the image and fill it in accordingly.

With simple patterns, it does a pretty good job. With complex image patterns, particularly the factal-like nature of edges found in nature, where the same pattern is found throughout a very wide range of scales, from the jagged coastline of a country to the jagged edge of a single rock, it does a very poor job.

Regardless, when dealing with priceless images of other worlds, it should be a felony to compress them in a lossy mode for any purpose other than to use as thumbnails (but the underlying image should be made available), or printed pictures in a magazine.

Unfortunately, it's lossly compressed pictures on various websites which get so jacked up that people can't tell the difference between cornfields in Iowa and compression artifacts.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

I was just commenting on the way that the author of that webpage seems to have compared the various algorithms. I don't have a problem with using a reconstructed image, I'd like to see them use a lot of different types of images with reconstructed being maybe one of them. Each algorithm tends to be better with different types of images, and reconstructed ones might even exaggerate those differences. Different algorithms will appear at the top, with different images.Original digital images too. Maybe we could make even simple possession of magnifijuana a misdemeanor.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

I think I've found an example of magnifijuana on the Math Pages: The Portraits of Emilie du Chatelet. What do you think, Mugs?