Hi Primoz,

I agree to your point that PNG files are bulkier than JPEG with many photographic images.
The reason why we chose to support PNG was because not all phones have the JPEG file decoding JSR 185 API support.
To keep the application compatible with most phones, we limited the support just to PNG.

Meanwhile, PNG is a better choice than JPEG for storing images that contain text, line art, or other images with sharp transitions that do not transform well into the frequency domain. Where an image contains both sharp transitions and photographic parts a choice must be made between the large but sharp PNG and a small JPEG with artifacts around sharp transitions.

Various tools are available for optimizing PNG files. OptiPNG and pngcrush are optimizers for PNG files that can be run from a command line in a Windows Command Prompt or from a Unix or Linux command line, and are very effective at reducing the size of PNG files for the web, especially those exported from the graphics creation programs with poor PNG handling. Other tools such as AdvanceCOMP and Ken Silverman's PNGOUT are capable of reducing the filesize even further, practically giving the competent user the smallest filesize possible for a given PNG image.

We also are considering a seperate build for phones that support the JPEG decoding API in the near future, we will keep you informed on that.

Thanks,

Admin