[lulalala]

Originally Posted by Phantom_E

My experience in lossless compression of image files gives an average of < 10% and in individual cases can actually result in a larger output file. A scan of the net shows that solid mode can do slightly better than basic PkZip, but personally I don't think the difference is worth writing home about.

Yes my sources are digital. When difference between frames are small, and each subset contains 50+ similar images, I can compress 200mb BMP files to a 6 mb 7zip file. Solid mode acts like IPPPP..., just that it is not random accessible.

Originally Posted by Phantom_E

Is your original source digital? Even if it was a digital source some of the following still applies.
Digitization is inherently lossy. The major issue is the Nyquist limit, but there are others involving the physical hardware employed in the processing (or capture).
Basically, If you do 10 successive scans of the same image you will get 10 different files.

Yes my sources are digitally created images. Therefore scanning is irrelevant.

Originally Posted by Phantom_E

Lossless in terms of video processing only applies to how much degradation subsequent processing will cause.
If this is a one off archive then only the losses for the decoding step apply. The display device will introduce some loss.
If multiple decoding and then recoding steps apply then lossless increases in importance.

So is x264 lossless mode not really lossless? My file format is design to be decompressed by the decompressor I want to write, not viewed by video decoder. So I thought I can make it to output without quality loss.

Originally Posted by Phantom_E

In these days of multi terabyte storage units and Blueray, do you have a need for compression at all?

Part of your research should include just how much loss you can have and still retain the level of detail required.
None is not one of your options.

I plan to have true lossless, just like 7z. From your reply it seems I misunderstood x264's lossless mode. Can you give some references that I can study?

Originally Posted by Phantom_E

Good luck with your project.

Thanks. Is it okay if I move this to the x264 board? The theory questions may be answered over there?