Cisco OL-18696-01 Development Manual page 23

Chapter 2 CiscoIPPhone XML Objects
Tip Before displaying a graphic image on a Cisco Unified IP Phone, the software clears the pane dedicated
to services. If a service has text or other information that must be preserved (including the title area), the
information must get redrawn as part of the graphic. If the title is to be hidden, the graphic must be large
enough to cover it.
CiscoIPPhoneImageFile
The latest generation of Cisco Unified IP Phones have higher-resolution displays with more color depth.
The Cisco Unified IP Phone 7970G, for example, has a display area of 298x168 pixels available to the
Services pane and renders images in 12-bit color.
To support these more advanced displays, a new XML object allows the use of color PNG images in
addition to the grayscale
the
image data, the
The web server must deliver the PNG image to the phone with an appropriate MIME Content-Type
header, such as image/png, so the phone recognizes the content as a compressed, binary PNG image. The
PNG image can be either palettized or RGB, and the maximum image size and color depth are model
dependent (see
Table 2-2 Cisco Unified IP Phones Display Image Sizes and Color Depths
Model
Cisco Unified IP Phones 7905G, 7906G,
2
7911G, 7912G , 7931G
Cisco Unified IP Phone 7920
Cisco Unified IP Phone 7921G
Cisco Unified IP Phones 7940G/60G
Cisco Unified IP Phones 7941G, 7941G-GE,
7942G, 7961G, 7961G-GE, 7962G
Cisco Unified IP Phones 7945G, 7965G
Cisco Unified IP Phone 7970G/7971G
Cisco Unified IP Phone 7975G
Cisco IP Communicator
6921, 6961
6941
1. Represents the size of the display that is accessible by Services—not the full resolution of the physical display.
2. The Cisco Unified IP Phones 7905 and 7912 have pixel-based displays, but they do not support XML images.
If the number of colors in the image is not reduced to match the phone capabilities, the image will be
dithered by the phone and yield less than desirable results in most cases. To reduce the number of colors
in a graphics editing program, such as Adobe Photoshop, use the "Posterize" command. The "Posterize"
OL-18696-01
CiscoIPPhoneImage
object, except for the image data. Instead of using the
CiscoIPPhoneImage
tag points to the PNG image file.
<URL>
Table 2-2).
Resolution
(width x height)
N/A
128 x 59
176 x 140
133 x 65
298 x 144
298 x 156
298 x 168
298 x 168
298 x 168
396x81
396x162
objects. The
CiscoIPPhoneImageFile
1
Color/Grayscale
/Monochrome Color Depth (bits)
Grayscale 1
Grayscale 1
Color 16
Grayscale 2
Grayscale 4
Color 16
Color 12
Color 16
Color 24
Monochrome —
Monochrome —
Cisco Unified IP Phone Services Application Development Notes
XML Object Definitions
object behaves like
tag to embed the
<Data>
2-9