Why is iTunes converting artwork from .jpg to .png?
I am quite careful in trying to add the very best album artwork I can to my library. I occassion I may find a .jpg file of an album's artwork I think may be better than what I have. I will take a copy of the album artwork out of my iTunes library and using Preview compare it to the 'new' jpeg file. I have noticed recently and I am assuming since iTunes 10.4 that the artwork I copy out of iTunes has been converted to a .png file now. As an example I recently put in a .jpg file of 600 x 600 image size, about 160 kb in file size and at 300 dpi. Later I took a copy of it from my iTunes library (these are all embedded images that I manually added) and the copy was suddenly a .png file of 600 x 600 but reduced to 72 dpi and increased to 335 kb.
What is happening and why is this happening? This could really bloat the size of a library and have an impact on iPods, iPhones and iPads when synching music with album art.
Although I have tested this several ways I just added a new .jpg file to my iTunes library. I then selected a song from that album, used Get Info, went to the Artwork tab and dragged it to the desktop. This image as I said above was now a .png file.