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Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
OL-23092-01
Chapter 6 Customizing the Cisco Unified IP Phone
Creating Custom Background Images
PNG File Requirements for Custom Background Images
Each background image requires two PNG files:
•
Full size image—Version that displays on the on the phone.
•
Thumbnail image—Version that displays on the Background Images screen from which users can
select an image. Must be 25% of the size of the full size image.
Tip
Many graphics programs provide a feature that will resize a graphic. An easy way to create a thumbnail
image is to first create and save the full size image, then use the sizing feature in the graphics program
to create a version of that image that is 25% of the original size. Save the thumbnail version by using a
different name.
The PNG files for background images must meet the following requirements for proper display on the
Cisco Unified IP Phone:
•
Full size image—320 pixels (width) X 216 pixels (height).
•
Thumbnail image—80 pixels (width) X 53 pixels (height).
•
Color palette:
–
(for Cisco Unified IP Phone 7971G-GE and 7970G)—Includes up to 12-bit color (4096 colors).
You can use more than 12-bit color, but the phone will reduce the color palette to 12-bit before
displaying the image. For best results, reduce the color palette of an image to 12-bit when you
create a PNG file.
Tip:
If you are using a graphics program that supports a posterize feature for specifying the
number of tonal levels per color channel, set the number of tonal levels per channel to 16 (16
red X 16 green X 16 blue = 4096 colors).
–
(for Cisco Unified IP Phone 7975G, 7965G, and 7945G)—Includes up to 16-bit color (65535
colors). You can use more than 16-bit color, but the phone will reduce the color palette to 16-bit
before displaying the image. For best results, reduce the color palette of an image to 16-bit when
you create a PNG file.
Tip:
If you are using a graphics program that supports a posterize feature for specifying the
number of tonal levels per color channel, set the number of tonal levels per channel to 40 (40
red X 40 green X 40 blue = 64000 colors). This is as close as you can posterize to 65535 colors
without exceeding the maximum.