I just noticed this. The resolution on the splash screen is normal the way it should be. Rite before it loads it changes to a lower resolution. I had a picture with alot of black shades and color fading. Now it looks great at first once the z2 boots it looks like 8 bit color or something. Plus if you go to the screen to change the back grounds the picture preview screen shows it at full resolution. Once you load it looks bad.

You will only notice this with dark colors.

Is it a resolution change or a color depth change? What resolution is your picture? Best thing to do it start with a sock picture resolution like the images built into the Z2 (500x240 if memory serves) and when editing the pictures (I like photoshop) do a "save for web" instead of a "save as" and it makes a very compliant jpg and the resolution is the stock native needed for the screen and it looks the same all the time no matter what.

I have always done this (made my background and splash images based off the resolution of the stock images) and what I see on the PC is the same on boot and as a background.

yes its a color depth issue all the dark blacks turn grey. Im going to have to try that "save for web" option.