We would like to deliver our photo wallpapers as JPEGs in 12-bit format, since most Nokia color phones have 12-bit displays (4,096 colors). However, our preferred image editing tool, Photoshop, does not seem to support exports of JPEGs in 12-bit.
Here are our specific questions:
1. Are 12-bit JPEGs the most popular format for photo wallpapers? Or do you recommend instead offering JPEGs at 8-bit, 16-bit or 24-bit? Or should we consider another format, such as PNG?
2. What image editing tool do you recommend we use for creating photo wallpapers with best results? Is there a special trick to using Photoshop for 12-bit JPEGs, or should we consider using another program, such as DeBabelizer?
3. Do you know of any special techniques for optimizing the look of photo wallpapers, specifically to avoid color banding in 12-bit? We are familiar with the use of dithering for 8-bit GIFs, but those techniques may not apply for 12-bit JPEGs.
4. Which of your popular color phones do not support JPEG wallpapers? (besides Sony T68 and Motorola 720) Which models do you recommend we support with 8-bit GIFs (using the web palette)?
5. Do color logos for Nokia phones (100w x 50h) work best as GIF or JPG files?
We would be grateful for any recommendations you might have for the optimal way to deliver our images to Nokia customers.
1. I think the most popular images for wallpaper are 24-bit JPEG's. I suggest you use 24-bit images for wallpapers. There might be some special cases, ie. the image is very, very detailed, where the image doesn't look that good on phone display. Using 8-bit images might be a good idea for using in "cartoon like" images
2. You can use whatever you feel comfortable. Don't know which tools offers 12-bit mode though.
3. Well, I guess you're more expert when it comes to optimizing graphics...But in general there's no point for making those images very detailed, since you can't see details in small screens.
4. All Nokia phones with color display support wallpapers and they use 12-bit displays.
5. This, again, depends what kind of image is used, ie. is it a photo or a cartoon like.