Best compression method?

[chaoliang]

I find that the LZW compression for TIF quite good. It compresses about 20% and is lossless.
I don't know how good is the recovery function of WinRAR. I only used it once. If you compress the files with it and then prove once, after that burn them on a CD, the files should be quite safe, I suppose.

[nikai]

Originally posted by Pace
Is PNG as sturdy as TIFF though? Or as sturdy as JPEG?

Yes, furthermore it's completely patent-free.

But what I like best is pngcrush http://pmt.sourceforge.net/pngcrush/ which allows you to optimize png compression.

[Pace]

Never actually thought of PNG, but I'm not limiting this just to large TIFFs or other images formats

[TnT]

http://www.libpng.org/pub/png

Its a very scalable format. It can be used to replace gifs because it compresses better and has alpha transparency. For higher end purposes it supports up to 48 bit truecolor, is lossless, and I don't know much about TIFF, but according to the website the TIFF specification is very loose which can cause problems when loading in different applications.

I pretty much only use PNG graphics now. I don't do a lot of emailing of images to people, so I usually don't have much use for JPEGs.

[Pace]

TnT: What apps do you use to make the PNGs? Any difference in the compressions?

[Ribbit]

The compression method (LZ77? I forget) used in PNG is supposed to be better than LZW (as used in TIFF).

Photoshop isn't very good at making PNGs (they come out a lot larger than they should). Use pngcrush on them.

Pngcrush rocks

Oh, and the PNG format has a few robustness features as well, so I wouldn't worry much about that.

[TnT]

Since you already have the images you can just go ahead and get http://www.irfanview.com. To do editing I use http://www.gimp.org and Picture Publisher by the defunct Micrografx.

Irfanview is just an awesome image viewer and I think it has batch processing capabilities.