PNG compared to JPEG and GIF
Posted on 2006-11-08
I've used GIF and JPEG for ages now, and begin to discover PNG. I hear from many people it's better, and I know that transparancy is better in PNG - if supported by the browser of course.
Normally I use JPEG for photo's. If I use PNG (24 bits), the image size is much bigger, and I cannot specify a compression rate (using Photoshop 6). As an example I took a photo of 800 x 600 pixels. Saved as PNG it was 800kb, and the JPEG version varied between 100kb (for high quality or 60%) and 500kb (100% quality). So the best JPEG quality is half the size of the PNG. Why is PNG better?
If I save to PNG (version 1), then reopen the saved PNG (800 kb big), save that again as PNG (version 2), the size grows to 950kb. If I reopen the last PNG (v2) and save it again as PNG (version 3), it seems to keep the last size. Is this always the case? Is PNG 24-bits lossless? Or at least not incremental on losing information?
What do you prefer? JPEG or PNG?
How about GIF? I think I won't use it anymore. I've noticed PNG-8 has comparable file sizes. I never use animated GIFs, so I don't need that (and don't know if PNG supports animation). Do you have reasons to prefer GIF over PNG?