Axis Communications thermal network camera Image, 264, Click Save to apply the new settings

AXIS Q1931–E Thermal Network Camera

Video and Audio

•Video & Audio > Video Stream. Under Preview, click Open and select the Show pixel counter option to enable the rectangle in the image. Use the mouse to move and resize the rectangle, or enter the number of pixels in the Width and Height fields and click Apply.

•The Live View page in Internet Explorer in Windows. Right-click in the image and select Pixel counter. Use the mouse to move and resize the rectangle.

Image

The default image settings can be configured under Video & Audio > Video Stream. Select the Image tab.

The following settings are available:

•Resolution. Select the default resolution.

•Compression. The compression level affects the image quality, bandwidth and file size of saved images; the lower the compression, the higher the image quality with higher bandwidth requirements and larger file sizes.

•Rotate image. If required, the image can be rotated.

•Palette. The image can be colored by applying a palette. Colors in the image indicate temperature differences and can be used to improve visibility of fine details. The palette selected here is used as the default palette, other palettes can be selected on the Live View page.

•Mirror. If required, the image can be mirrored.

•Maximum frame rate. To avoid bandwidth problems, the frame rate allowed to each viewer can be Limited to a fixed amount. Alternatively, the frame rate can be set as Unlimited, which means the Axis product always delivers the highest frame rate possible under the current conditions.

•Overlay settings. See Overlay, on page 17.

Click Save to apply the new settings.

H.264

H.264, also known as MPEG-4 Part 10/AVC, is a video compression standard that provides high quality video streams at low bit rates. An H.264 video stream consists of different types of frames such as I-frames and P-frames. An I-frame is a complete image whereas P-frames only contain the differences from previous frames.

The GOV length is the number of frames between two consecutive I-frames. Increasing the GOV length may save considerably on bandwidth requirements in some cases, but may also have an adverse affect on image quality.

The bit rate can be set as Variable Bit Rate (VBR) or Constant Bit Rate (CBR). VBR adjusts the bit rate according to the image complexity, using up more bandwidth for increased activity in the image, and less for lower image activity. CBR allows you to set a fixed Target bit rate that consumes a predictable amount of bandwidth. As the bit rate would usually need to increase for increased image activity, but in this case cannot, frame rate and image quality are affected negatively. To partly compensate for this, it is possible to prioritize either frame rate or image quality. Not setting a priority means that frame rate and image quality are equally affected. You must save your settings before they can take effect.

The current bit rate can be set to appear as text overlay. To do this, select the Include text check box option under Overlay Settings and enter the modifier #b in the field.

MJPEG

Sometimes the image size is large due to low light or complex scenery. Adjusting the maximum frame size helps to control the bandwidth and storage used by the Motion JPEG video stream in these situations. Setting the frame size to the Default setting provides consistently good image quality at the expense of increased bandwidth and storage usage in low light. Limiting the frame size optimizes bandwidth and storage usage, but may give poor image quality. To prevent increased bandwidth and storage usage, the maximum frame size should be set to an optimal value.

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