how can I change the camera resolution for taking photos.
I have a geeksphone peak and I cannot find how to change that configuration.
I'm afraid this is not currently possible in the Firefox OS camera app. Please see the bug report here:
It looks like post processing images above 2 megapixels was causing a problem on devices with 256MB of RAM. Your Peak has 512MB of RAM so hopefully you will get the option to increase the resolution in a future software update.
I hope that helps.