Default-Portrait.png for iPad: any way to make the

问题:

I'm making a Universal App using MonoTouch, and I'm adding my Default-Portrait.png file. That file alone (a 768x1004 .png file) is adding 711k to the size of the app. My app itself is only about 7 megs, so it's adding 10% just for the splash screen.

I could easily make this thing an 80k jpg file instead of a png, but the device doesn't seem to look for a .jpg file. Does anyone have tips for reducing the size of this launch art?

At this point, I'm thinking I might just leave the launch art out and load my own jpg and display it as soon as I have the ability to. That'll keep my app size down, but it's not as nice as having the launch art scale in immediately like most apps do.

回答1:

Hmmm...given the screen of the iPad and the visual quality users are expecting, I'd just leave it like that.

But if you do want to reduce the disk space, try going to Project > Edit Project Settings > Build (tab at top), and searching for a parameter called "Compress PNG Files." Make sure that's checked. It'll run the pngcrush utility before loading the file onto disk (check the size of your IPA archive after to see if it had any effect).

回答2:

pngcrush is nice as well, however that will not reduce the quality of you image. If reducing the quality of the image is an option for you, then you might try this tool: http://www.punypng.com/ - or just use an image editing tool to "optimize" the image ...

回答3:

I recommend pngout if you want to really squeeze those PNGs down, and this won't cost you any quality. It simply removes unnecessary metadata (like pngcrush) and uses its own compression algorithm which is compatible with the regular decompressor used in PNG (zlib). It's really slow, though.

A simpler option is to try "Save for web" in your image manipulation program of choice. Exporting from Acorn (not just the regular save) sometimes gives me vastly smaller files. This is especially true for default images which have large, uniform areas in one colour (screenshots, a small logo in the middle of a black screen).

回答4:

Is there any reason why you want to reduce the file size that badly? I don't think it matters in your case. I just checked 3 of my apps and the Default.png (of various portrait/landscape varieties) is between 29KB and 422KB, so whilst yours do seem a little heavy, your still way under the 3G download limit.

回答5:

Are you positive it's adding that much to the size of the app? Did you compare a before and after?

Xcode uses pngcrush on the images for you. I know because I just tried to substitue jpegs for pngs and got the following result:

So, in short, there's not a lot to be done except simplify the image beforehand. Xcode will handle the rest.