Optimising Graphics for iPhone 4. Help

ozboybrian

I've currently been working on a game I hope to release by the end of next week.

Everything was going fine untill I realised there Graphics where suited for the 3GS and not the iPhone 4.

It's been very difficult and I can't believe the complications caused by this and i've started to fall behind on the actual game itself.

So if I just set it up for a 3GS for now and update the Graphics (Turn resolution independence on) once the game is complete. Would that make things easier, or is that ever harder?

Thanks in advance!

gazjm

It should'nt be too difficult, all you have to do is replace the graphics in the project with the same graphics only double resolution. The only thing which can complicate it is if you drag the image into the actor it will resize it to the new image size. But you don't need to do that. I don't think it would be any easier leaving it all till the end.

craps

With regards to graphics for the iPhone 4. I have photos that are in the
300kb size range that need to be sized down. Currently they are at 960x640 72 dpi.
I noticed in photoshop that if you save them for the web they can be saved
As 8 bit or 24 bit png size. They both look great even on the iPad.
The 8 bit format is half the kb saved size.
What do you think about they saved file size
For iPhone 4 and iPad apps?

dazzleme

Here's some good advice FireMapleGames gave a little while back
http://gamesalad.com/forums/topic.php?id=15070#post-115181

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Wherever I could, I saved my images in the PNG-8 format under Save for Web... in Photoshop. Which creates a 256 color palette for the image. If it doesn't look too awful, you can also lower that number to get it even smaller.

PNG-8 also allows you to make one single color transparent. I use that whenever possible.

If the image needed full transparency, I saved it out as PNG-24.

I then ran all of my images through ImageOptim.

Like Colin says, this only lowers the overall file size, not the RAM needed to display the images.
Lowering the file size helps your sanity as well. It of course makes it much quicker to upload/ download/ install on your phone/ etc. Those extra minutes start adding up when you are testing your game heavily.
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I just tried "save for web" on some 960x640 images I needed to optimize. I found that saving as a jpg, they saved much smaller than png. I didn't need to make any customization choices, and they looked just as good as the png image. However, GameSalad crashed every time I tried to import the image. I then took the exact same .jpg image and renamed it as .png. This time the images imported into GS just fine and also looked great. I then tried this on a 122x64 image and didn't get the same results as far as quality, so I saved as a png-8. The final image looked great and was much smaller than I originally had.

To sum it up, I hope the technical info from FMP I pasted above is helpful to you, and that my experimentation notes are helpful in some way too. Good luck!

craps

Thanks for such a detailed and reason based answer. It was more than helpful.

Asymptoteell

Good luck with release!

dazzleme

Hey guys, it looks like I led you partially wrong. I noted earlier that I was able to save images as .jpg and then change the file name to .png without any trouble. That turned out to be only partially true. While it's true that GS didn't crash (like it did with the .jpg extensions), and the images looked great while testing on the computer, the image files did NOT port through to my iOS device - the re-named .jpg images were just blank white space. To test if it wasn't something else I did wrong, I replaced with original .png files, and the images came through on the iOS device as expected. Guess I can't cheat technology like I'd hoped to this time. Sorry for any inconvenience this may have caused you.

craps

GS needs to add jpg file support. Would that not be nice. I could cut 300K png images down to 100 K jpg and not lose anything in the viewing quality.

SlickZero

It does have .jpeg support. Anything that does not require transparencies, I use .jpeg for file size optimization. There is something weird going on if your .jpegs are crashing GameSalad. You may try to restart everything including the computer and see if maybe that doesn't help.

And changing the extension doesn't change the file format unfortunately, if anything it has potential to cause problems.

craps

SlickZero - thanks you are correct but there seems to be one very large problem. I saved my large images as jpg's and their size was around 120K. When imported into GS they were changed to png files and went back close to their original size ( 350 K). So it really does not help with the overall game size.

I am I missing something.

SlickZero

Well, yeah, that's true. Gamesalad does convert it to png, but I get a just a little bit smaller file size if i compress with .jpeg and import as .jpeg and let GS convert to .png, rather than going straight with .png. And I only do that with images that have no transparencies.

LumpApps

What I don't read here that jpeg is not a lossless compression format while png is.
So png in general should give nicer images.
That said it also depends on what your image looks like and how many compression you use in your jpeg.

The fact that the jpegs imported in gamesalad giving smaller png's says something about the way gamesalad compresses png files. It apparently does a good job.
I ask myself if an image saved as png and then ran through ImageOptim isn't as good as gamesalads png.
Something I should test perhaps.

ozboybrian

Got more then I asked for thanks guys!
Lots of useful information : )