This may help.
Also try this...Dimensions of boot, radio, mp3 and scan picture must to be 720x576 pixels in PAL format.
Path where boot image are stored is /root/platform/kernel and named is bild
Path where other pictures are stored is /var/tuxbox/config/enigma/pictures/
Program what is usually used to make boot/background pictures is TMPGEnc
So little brief for using TMPGEnc:
#1 Download TMPGEnc from official site
#2 Unzip the file to your chosen destination.
#3 Double click the 'TPMGEnc.exe MPEG Encoder' file and click 'OK' on the small pop up window and then click 'Cancel' on the 'Project Wizard (1/5)' window that appears.
#4 Next screen, bottom right...'Stream type', check the box 'ES (Video only)'.
#5 Next, bottom left...'Video source:' click on 'Browse' and select the background/photo that you want as your new boot logo for the Dreambox.
#6 Next, bottom left... 'Output file name:' click on browse and choose the path for your finished 'new' boot background/photo and edit the name to 'bild' (minus the '....' and in lower case) ie: the line that apperars in the 'Output file name:' should read similar to C:\Documents and Settings\Whatever\My Documents\bild ( the actual name of the photo does NOT appear).
#7 Next, bottom right...click on 'Setting' and check that the value settings are:
.....'Stream type:' = MPEG-1 Video
.....'Size' = 720 x576 pixels
.....'Aspect ratio:' = 1:1 (VGA)
.....'Frame rate:' = 25 fps
.....'Rate control mode:' = Constant bitrate (CBR)
.....'Bitrate:' = 12000
.....'Motion search precision:' = Normal
When checked, click 'OK' to exit the screen.
#8 Top left click 'Start', if all is goes well, the '100%' bar appears and your completed 'bild' file is to be found in your chosen 'Output...' location.
Transferring the new 'boot' photo to the Dreambox.
ENSURE that the image that you want to change the boot/radio background pictures for, is the image RUNNING in the Dreambox when editing.
With the image, that you want to change the boot photo for, running in the Dreambox, open your chosen FTP prog and transfer your new 'bild' file to the path: 'root/platform/kernel', you can overwrite or delete the pevious 'bild' file that exists.
Exit your FTP prog and reboot the Dreambox.
You should, if all ok, see your new photo on the next boot.
*** If You want to change boot picture before compressing image (after command make rebuild-flash ) , just copy it into /tuxbox-cvs/root/cdkflash/boot/root/platform/kernel before executing command make flash-compress