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Choosing Your Application
32
Picture frequency for Networking Applications
When used in a TCP/IP networking environment, the AXIS 2420 delivers up to 30/25
(NTSC/PAL) images/second. The perceived frame rate in your browser is typically limited
by:
• the number of clients accessing the images
• your computer and browser
• the chosen image resolution and compression
• the lighting conditions at the point of installation
• available network bandwidth
• the complexity of detail and color variation within the image
Note:
The AXIS 2420 is available in NTSC and PAL variants to accommodate the different power supply
frequencies in the USA and Europe.
Image Compression Ratios
Although the file size of a JPEG-compressed image depends upon the actual content of the
image, images containing great detail generally generate larger files. Image quality is
largely controlled through the level of compression; where high compression yields small
files, and low compression maintains higher image quality at the expense of larger files.
The table below is derived from real-life tests, and defines the average file sizes for each
supported image resolution:
Resolution
4CIF (704 x 480)
CIF (352 x 240)
* Maximum performance for a single viewing client.
Note:
Using a modern computer will avoid introducing any unnecessary constraints on the image fre-
quency.
NTSC
File size (kb)
Max fps*
7 - 150
10
1.4 - 40
30
AXIS 2420 User's Manual
PAL
Resolution
File size (kb)
4CIF (704 x 576)
8.5 - 180
CIF (352 x 288)
1.7 - 50
Max fps*
8
25
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