large image file to save space?

[fmx]

Hello, as "Nokia UI API Programmer's Guide" says putting small .png images to a large image file can save space, but I found in the Nokia game examples, seems they didn't use this way to save the space for images.
Is it a good idea to store small images in a big .png file?

Thank you!

[dying]

Each png file has a file head and end block. Puting small png files into one large file will cut off most file heads.

[fmx]

but the game examples that Nokia gave out, they all didn't store small .png images into a big image file, why?

[kisember]

Just for better understanding.
To make a simple example, how to use filmstrip images is not difficult, but if you built it in your game, source will be much harder to examine.

[fmx]

but also other developers they didn't use this way in developing their games, I couldn't find a game that it used only a big image file instead of small image files, so I'm quite confused if I should store small images into a big image file in my game.

[shmoove]

The tradeoff here is that using one big image, or filmstrip, will make your jar smaller (because one big image uses less memory than many small ones); but it will make your game a little slower and maybe (depending on the implementation) it will need more runtime memory. If your jar isn't too big, then stay with the small image approach since it's more effective. If you need the jar space then you can use the big image approach.

[fmx]

yes, this makes me understand when I should consider using this way, thanks! ^~^