Image Optimization Confusion

Graybay

I am working on optimizing a few images for a project right now, and I've been doing some research around the forums here. There are a few things that I am having trouble to understand.

Why do people choose to use png8 over jpeg? I am getting much better file sizes with jpeg. Also I was reading that, and I quote from firemaplegames "A 1024x768 image requires 2.3 MB to display (regardless of its file size.)" Why do we bother even using compression if they take the same amount of ram no matter the file size? Is it just for the overall size of the game installation file? Does gamesalad convert to its own format or something when the art is imported?

I would really appreciate if someone could clarify this for me.

jonmulcahy

iOS is optimized for PNG images, and GameSalad converts everything to PNG when you import images.

The reason to reduce file size is to hopefully keep the game under 20MB so it can be downloaded over 3G on iPhones.

Graybay

Thank you jonmulcahy. So if I make a png to start with, gamesalad will keep it just the way I compressed it?

Chobbiface

Graybay said:
Thank you jonmulcahy. So if I make a png to start with, gamesalad will keep it just the way I compressed it?

I don't think that is strictly the case. I've used png images compressed with imagealpha. Once imported into GS, they seem to balloon in size a bit. Not sure exactly how it works, but I think GS somehow uses it's own compression algorithms.

Graybay

I guess the only choice I have is to do some experiments and find out. Is there a way to see the technical details of an image within GS?

tenrdrmer

Yeah GS runs its own Compression When you publish the app. Just make your .pngs import and let GS do the rest.

Graybay

IS it best to import a png without compression then, to save as much detail as possible for gs to compress?

tenrdrmer

I would import them as you create them. Just make sure they are 72 dpi and you will be good to go. I never bother with Compressing anything before or after importing.

tenrdrmer

Oh and in regards to Your Question about ram and File Size. The two have nothing to do with each other. So the only thing reducing file size will do is get you under the 20MB 3g download limit. Ram is a whole different beast.

Graybay

Thank you for clearing that up tenrdrmer. One last thing though, is there a way to see the size your final game will be before publishing to the app store?

tenrdrmer

the only only way to be 100% sure is to publish to an .app you can that as an adhoc or as a distribution and just look at the file size of the .app file. Thats the only way to know 100% what its going to be.

Cheers