From the help file in the software
Welcome Image
Load a bitmap as a welcome screen to the radio. Click the Select button to select a bitmap picture or click the Remove button to remove the screen from the radio display.
Notes
The resolution and color depth for the picture are as follow: 160 pixels (width) * 72 pixels (height) and 256 color for Mobile, 132 pixels (width) * 90 pixel (height) and 256 colors for the Portable Full Keypad model, and 132 pixels (width) * 72 pixels (height) and monochrome color for Portable Limited Keypad model. In Handheld Control Head (HCH) mode, the resolution and color depth for the picture is 132 pixels (width) * 90 pixels (height).
For SL Series radios, the resolution and color depth for the picture are as follows: 320 pixels (width) * 240 pixels (height) and 16bit (R5-G6-B5) color.
When the Welcome Image is used, the Radio Name text will not be displayed during the power-up sequence.
If the mobile radio is in HCH mode, you cannot customize the Welcome Bitmap for HCH. Therefore, the default Welcome Image will be used on the welcome screen regardless of your selection of bitmap image.