Video and Image Processing Blockset™

Video Viewer - Display binary, intensity, or RGB images or video streams

Library

Sinks

Description

The Video Viewer block enables you to view a binary, intensity, or RGB image or a video stream. During code generation, Real-Time Workshop does not generate code for this block.

Use the Image signal parameter to specify how the block accepts a color video signal. If you select One multidimensional signal, the block accepts an M-by-N-by-P color video signal, where P is the number of color planes, at one port. If you select Separate color signals, additional ports appear on the block. Each port accepts one M-by-N plane of an RGB video stream.

If you set the Image signal parameter to One multidimensional signal, the Use colormap and Specify range of values parameters appear on the block dialog box. If you select the Use colormap check box, you can use the Colormap parameter to specify a colormap or a call to a colormap-generating function.

MATLAB^® provides a number of functions for generating predefined colormaps, such as hot, cool, bone, and autumn. Each of these functions accepts the colormap size as an argument, and can be used in this parameter. For example, if you enter gray(128), the image is displayed in 128 shades of gray. The color in the first row of the colormap matrix represents the minimum input value, and the color in the last row represents the maximum input value. Values between the minimum and maximum are quantized and mapped to the intermediate rows of the colormap matrix. For more information, see the MATLAB colormap function documentation.

If you select the Specify range of values check box, you can use the Minimum input value and Maximum input value parameters to define the range of your input. If you do not specify a range, the block assumes that Boolean, double-precision floating-point, and single-precision floating-point signals range from 0 to 1, and any other signals range between the minimum and maximum values supported by their data type.

Dialog Box

The Video Viewer dialog box appears as shown in the following figure.

Image signal

Specify how the block accepts a color video signal. If you select One multidimensional signal, the block accepts an M-by-N-by-P color video signal, where P is the number of color planes, at one port. If you select Separate color signals, additional ports appear on the block. Each port accepts one M-by-N plane of an RGB video stream.

Use colormap

Select this check box to specify a colormap. This parameter is available if you set the Image signal parameter to One multidimensional signal.

Colormap

Specify the colormap to apply to the intensity image or video by entering a 3-column matrix defining the colormap or a call to a colormap-generating function such as hot, cool, gray, or spring. This parameter is available if you select the Use colormap check box.

Specify range of values

Select this check box if you want to define the range for the input. This parameter is available if you set the Image signal parameter to One multidimensional signal, and is only valid for Intensity input images. If data values exceed the specified range, they are saturated to the specified minimum and maximum values.

Minimum input value

Use this parameter to define the range of the input; enter the smallest input value. This parameter is available if you select the Specify range of values check box.

Maximum input value

Use this parameter to define the range of the input; enter the largest input value. This parameter is available if you select the Specify range of values check box.

See Also

Video To Workspace

Write AVI File (Obsolete)