Why do the Pedias convert images?

[jenv]

If I drag a PNG to a Pedia's cover area it accepts it as the new artwork. If I then drag that cover back to the Finder from a Pedia, it comes out as a JPEG. Since PNG is lossless and JPEG is not, vital image quality has been lost. I also note that if you drag a 200k JPEG to a Pedia and then drag it back, it turns into a much larger (500k, for example) image. That suggests that the Pedia is doing a reconversion every time, which on a lossy codec like JPEG loses image quality. Why don't the Pedias save cover images in the format they were received in?

[Conor]

The format used is JPEG highest quality. Since this is the format all the images are downloaded in from online, it was the deault format. (also when DVDpedia 1.0 came out PNG had just recently become an international standard) In the future we want to move to PNGs as we also prefer it. Because the compression is set at the lowest and the quantization step of compression is not done file sizes are larger than what can really be achieved with JPEG by using a more aggressive compression, but we keep the compression at a minimum to save image quality and hence the larger image size. We are interested in PNG for it's lossless quality and its ability to save transparency; as hard drive space becomes more avaliable we will be able to switch to PNGs.

[jenv]

Because the compression is set at the lowest and the quantization step of compression is not done file sizes are larger than what can really be achieved with JPEG by using a more aggressive compression, but we keep the compression at a minimum to save image quality and hence the larger image size.

Why recompress at all? You lose quality every time you do a decompress/recompress cycle even at low compression settings. If the input is any lossy codec doing a straight copy of the data and bypassing the recompression step would be much preferred. Interestingly, if you replace the JPEG in [Data Folder]/Covers with a PNG (cp new.png old.jpg) the Pedias can display the image normally. For now I've taken the step of dragging the cover to a Pedia then copying the original JPEG over the new JPEG created in [Data Folder]/Covers.