Documentation for Axxon PSIM 1.0.0-1.0.1.

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Compression rate settings

The image is compressed to reduce the size of video stream. Video is not compressed when it is displayed on the Monitor of the Server.

An increase in compression rate leads to video degradation. Axxon PSIM™ software compresses video right after its digitizing by the video capture card, prior to its recording and/or before transmitting it to the Remote Workstations.

Video compression rate is configured for each camera individually.

Axxon PSIM™ system uses the Quality setting for the compression rate parameter, which is reverse to the compression rate.

In most cases the default Quality setting is sufficient.

To change the video compression rate, do the following:

  1. Go to the Hardware tab in the System settings dialog box (1).
  2. Select the Camera object, created before, corresponding to the camera to be adjusted, in the objects tree of the Hardware tab (2). The settings panel for the selected object is displayed on the right of the Hardware tab.
  3. Go to the Basic settings tab on the settings panel of the Camera object (3).

  4. If it is necessary to improve the video quality, move the Quality slider to the Max (4).
    If it is necessary to reduce the size of video stream from the camera, move the Quality slider to the Min.

    Note.

    Use the viewing field to estimate video enhancement or degradation.
  5. Click the Apply button (5).

Key frame rate settings

Axxon PSIM™ software uses Motion Wavelet algorithm for video processing and compression. Processed by this algorithm, the video is the sequence of key − and delta frames. A key frame is a full frame of an image. A delta frame (differential frame) is an image containing only pixel blocks which differ from the previous key frame.

Motion Wavelet algorithm guarantees consistency of a frame regardless of key frame rate. With an increase of motion intensity in a frame, the size of delta frame is also increased and the quality of video does not change. With very intense motion (more than 70% of frame is engaged) the setting of key frame rate is ignored and every frame is processed as a key frame.

The best value of frame rate is set by default in Axxon PSIM™ software: every 8th frame is processed as a key frame. If there are no special requirements to video size and quality, it is recommended to keep the default key frame rate.

To change the key frame rate, do the following:

  1. Go to the Hardware tab in the System settings dialog box (1).
  2. Select the Camera object, created before, corresponding to the camera to be adjusted, in the objects tree of the Hardware tab (2). The settings panel for the selected object is displayed on the right of the Hardware tab.
  3. Go to the Advanced settings tab on the settings panel of the Camera object (3).
  4. Specify the required value of key frame rate in the Key frames interval field (4).
  5. Click the Apply button (5).

Key frame rate is now configured.

Setting delta frame creation criterion

Axxon PSIM™ software uses Motion Wavelet algorithm for video processing and compression. Processed by this algorithm, the video is the sequence of key −and delta frames. A key frame is a full frame of an image. A delta frame (differential frame) is an image containing only pixel blocks which differ from the previous key frame. To compare the pixel blocks of a key frame to those of the frame next to the key frame, the average brightness of blocks is compared. If the difference in brightness exceeds a preset value, the block is considered to have fixed motion, and it becomes a part of a delta frame. Otherwise, the block is considered to have no motion, and it is not included into the delta frame.

Legitimate values of pixel block brightness lie within 0-225 range. The block becomes a part of the delta frame by default, if the difference between its average brightness in the current frame and in the previous key frame exceeds 7 units. If this value is increased, the size of the delta frame is decreased, and the video stream size is consequently decreased, as a delta frame now contains less pixel blocks. Note that the blocks with useful motion data now are more likely to be excluded from the processed video and consequently there is video degradation. So, by reducing the value of the parameter setting the criterion for blocks to be included into a delta frame, you may improve the image while building up its size.

The best value of the parameter, which sets the criterion for blocks to be included into a delta frame, is defined by the brightness gradient of the video background and the moving objects in a frame: with a high gradient the parameter may be increased; with a low gradient the parameter value is to be decreased.

Note.

The Estimate motion parameter is ignored by the Motion Wavelet 7.1 and Motion Wavelet 7.1 Intr compressors.

To change the value of the parameter, which sets the criterion for the block to be included into a delta frame, do the following:

  1. Go to the Hardware tab in the System settings dialog box (1).
  2. Select the Camera object, created before, corresponding to the camera to be adjusted, in the objects tree of the Hardware tab (2). The settings panel for the selected object is displayed on the right of the Hardware tab.
  3. Go to the Advanced settings tab on the settings panel of the Camera object (3).
  4. Specify the value of the parameter, which sets the criterion for the block to be included into the delta frame, into the Estimate motion field (4).
  5. Click the Apply button (5).

Delta frames generation criterion is now set.

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