Clipboard oddities (with regard to pictures)
I've noticed that when copying pictures to the clipboard (such as from within Safari, Preview, GraphicConverter), the image is usually first converted to a different format, usually losing any compression; so then when the picture is pasted, the data size can be much larger than the originally copied picture.
I first noticed this when I used such methods to manually add album artwork to some music files in iTunes; the song file sizes increased dramatically, much more than expected. When I thought I was pasting a 200KB jpeg for instance, the song file would jump 2MB.
So I started experimenting and found more peculiarities. Take a jpeg file for instance, which is 76KB. If you
I first noticed this when I used such methods to manually add album artwork to some music files in iTunes; the song file sizes increased dramatically, much more than expected. When I thought I was pasting a 200KB jpeg for instance, the song file would jump 2MB.
So I started experimenting and found more peculiarities. Take a jpeg file for instance, which is 76KB. If you
- open in Safari, choose Copy Image from its contextual menu, then in Preview choose File->New from Clipboard, the result is a 733KB TIFF;
- open in Preview, choose Edit->Copy, and then New from Clipboard, same result;
- copy using either Safari or Preview, but then in GraphicConverter choose File->New->Image using Clipboard, the result is a 733KB PICT;
- open in GraphicConverter, choose Edit->Select All then Edit->Copy, then paste it as a new image either in GraphicConverter or Preview, the result is a 710KB PICT
- open in any of the above apps, then in iTunes select a song and in the album artwork pane in the lower left corner choose Paste from the contextual menu, the result is unknown format but it doesn't really matter though because either way you're left with a song file that's a lot bigger than it should be.
So you can see the reason for my frustration: GraphicConverter seems to always treat the clipboard as PICT, Preview treats it as either TIFF or PICT depending on the source, Safari treats it as...well, one of those two, depending on where you paste the picture. But none preserves compression when copying. The only program I've tested so far that preserves compression when copying is iTunes itself: if you go into iTunes and select a music file with album artwork and choose Copy from its contextual menu, then make new from clipboard in either Preview or GraphicConverter, tthe result is a PICT of essentially the file size you were expecting, with compression and all (but if you then copy that and make new from clipboard in either app, you're back to square one). Why a music app is capable of preserving compression when copying yet dedicated graphics apps aren't, I have no idea.
The only solution I've found to reliably get album artwork into iTunes is by dragging the picture file itself from the Finder to the little artwork pane in the lower left corner of iTunes; only then does it preserve the original image data size, and the song file size increases the expected amount. Dragging straight from Safari still explodes the file size, so yes this means if the cover art is found on the web, you must first download it to a file. What a rigamarole, when a simple copy/paste should suffice in such a modern operating system.
Much of my post has to do with iTunes, but I posted it here because it's really a more universal issue: is there any way to avoid this unintuitive format conversion that different apps seem to inconsistently render?
Message was edited by: nabziF
Power Mac G4 dual 867 Mirrored Drive Doors, Mac OS X (10.4.11)
