HI!...
I want to share with all of you people my last discovery about
the image quality on wallpaper images on 7650 (and may be on 3650 too).
I don't know if any of you notice that when you see a wallpaper picture on the default viewer, look better than after you put it and see it on the main desktop screen (telephone view). On desktop the picture looks a little more blurry, and decolored (desaturated).
Well, i discovered why and i have the solution, and now you will really want to remake all your wallpapers images, to get a real DELUXE Wallpapers Look 😃
The problem is that the system need a MBM picture format to use on desktop, and i am not totally sure, but i think that the background picture is actually a 256 color pic, not a 4096, may be to leave some fixed color palette for the system.
So the system convert any non bitmaped pic to a .mbm pic, like you can see on the c:/system/data/backgroundimage.mbm .. the image is always a mbm.
So... when you use a JPG like a Background the system convert that to mbm, and you lose some palette on that process and you will get a decolored wallpaper. You can notice the same effect when you see the Thumbnails of the JPG pics on the viewer look decolored beside the Thumbnails of the GIF pictures, becuase once again the system convert the JPG to a mbm pics to make the thumbs.
Even when you see a BMP pic on the default viewer look decolored, because the viewer are showing directly a 256 picture and is not converting it to a 4096 color pic, like the JPG pics showed on the viewer.
Well, here is the trick...
You will need a good photo software, like Photoshop 😊 for example...
There you have to:
1. Rescale you image to 174 x 132 (wallpaper size)
2. Make some little soft sharp (with sharpen filter, or KPT Equalizer work better because it's a softer sharp, not to hard)
3. Adjust the levels (or brightness and contrast) to make the picture look a little more darker on your PC monitor (but then you actually will see normal on the 7650 screen)
4. Increment the color saturation of the image in about 30% (no matter if you see it too saturated on your PC monitor)
5. And the most importan part, convert your image to a 256 color picture, using INDEXED Color mode (on photoshop), and use a Dither between 30 to 80% depending on the amount on different colors that the picture has, more colors use more dither.
6. Save as your picture in GIF format.
7. Put that pic like Wallpaper, and compare that pic with the original pic saved on JPG picture and puted like wallpaper.
The GIF Image is a bitmaped (fixed pallete 256 colors) picture, and is not converted by the system to use on the background, that make a BIG difference between JPG pic forced like a wallpaper, and a GIF pic.
You tell me then if you test this....
Attached you will see a test of this topic, two pic, one gif and one JPG, try both like wallpaper and you tell me wich one looks better 😃
well... that's all... and sorry for this LOOOONG topic 😉
cya! 8)