Settings to create transparent PNG's with minimal file size for mobile devices


I want to create a theme for android phones. I guess the best way to go is to create a file that is as light as possible.

Now I want to create the files in photoshop, they have to be transparent PNG's. Now I see that there are a lot of different settings I can use, for example the image mode: lab, rbg, etc. There are also different bits, 8 bit, 16 bit etc.

Now what settings can I use to create good sharp png's but with a minimal size.

Maybe someone could share some tips on exporting. I now export for web & devices, but maybe there is another option.

Maybe there is also better software than photoshop to do this.

8/4/2011 1:03:00 PM

Accepted Answer

The only color space to use for image prep for mobile devices is RGB. (You can use others temporarily for retouching purposes, but your final output will always be RGB, so best work in that space all the time.)

sRGB is the safest, since you don't know the capabilities of specific devices at design-time.

Save for Web is your best option inside Photoshop. 8-bit will result in significantly smaller file sizes than 24-bit, and the visible difference is often negligible, especially for small screens.

See this question on superuser for a comparison of several PNG compression utilities.

3/20/2017 10:18:00 AM

All pngs are 'good' and 'sharp' as they are losslessly compressed, unlike jpgs. It's just a matter of experimenting with settings that keep an amount of colour that you're happy with while keeping file sizes as low as possible.

In Photoshop, the 'Save for web' exporter allows you to view 3 different optimised versions of the output as well as the original. Use these to compare the outputs and find one that's acceptable for you.