Video Viewer
Display images or video frames
Libraries:
Computer Vision Toolbox /
Sinks
Description
The Video Viewer block displays images or video frames. This block provides simulation controls to play, pause, and step while streaming a video or image sequence. This block also provides tools to analyze the pixels of a region of interest.
Features of Video Viewer
Playback control — Control video playback using the Run, Step Forward, and Stop buttons.
Export to Image Viewer — To open the displayed image in a separate window using the Image Viewer app, select File > Export to Image Viewer. Alternatively, select the Export to Image Viewer button in the toolbar. For more information, see Get Started with Image Viewer App.
Pixel region analysis— To open the displayed image in a separate window using the Pixel Region tool, select Tools > Pixel Region. Alternatively, select the Inspect pixel values button in the toolbar. For more information about Pixel Region tool, see
impixelregion
.
Examples
Read and Display RGB Video from File
Read video frames from a multimedia file as their separate red, green, and blue components, and then display the video frames.
Ports
Input
Image — Input image or video
matrix | array
Input image or video, specified as an M-by-N matrix, M-by-N-by-T array, or M-by-N-by-C-by-T array. T is the number of frames in a video or image sequence, and C is the number of color channels.
Dependencies
To enable this port, select the One Multi-Dimensional Signal parameter. This parameter is enabled by default.
Data Types: single
| double
| int8
| int16
| int32
| uint8
| uint16
| uint32
| Boolean
| Simulink.ImageType
R — Red color component of image or video
matrix | array
Red color component of the image or video, specified as an M-by-N matrix or M-by-N-by-T array. T is the number of frames in a video or image sequence.
Note
Inputs to the R, G, and B ports must all have the same dimensions and data type.
Dependencies
To enable this port, select the Separate Color Signals parameter.
Data Types: single
| double
| int8
| int16
| int32
| uint8
| uint16
| uint32
| Boolean
G — Green color component of image or video
matrix | array
Green color component of the image or video, specified as an M-by-N matrix or M-by-N-by-T array. T is the number of frames in a video or image sequence.
Note
Inputs to the R, G, and B ports must all have the same dimensions and data type.
Dependencies
To enable this port, select the Separate Color Signals parameter.
Data Types: single
| double
| int8
| int16
| int32
| uint8
| uint16
| uint32
| Boolean
B — Blue color component of image or video
matrix | array
Blue color component of the image or video, specified as an M-by-N matrix or M-by-N-by-T array. T is the number of frames in a video or image sequence.
Note
Inputs to the R, G, and B ports must all have the same dimensions and data type.
Dependencies
To enable this port, select the Separate Color Signals parameter.
Data Types: single
| double
| int8
| int16
| int32
| uint8
| uint16
| uint32
| Boolean
Parameters
File
To access these parameters, select the File menu in the Video Viewer window
Open at Start of Simulation — Open video viewer window at start of simulation
on
(default) | off
Select this parameter to automatically open the Video Viewer window at the start of the simulation. Clear this parameter to prevent the Video Viewer window from opening at the start of the simulation.
Separate Color Signals — Enable separate R, G, and B color channels as input
off
(default) | on
Select this parameter to enable the R, G, and B input ports for separate color channels. If you select this parameter, the One Multi-Dimensional Signal parameter clears automatically.
One Multi-Dimensional Signal — Enable one multi-dimensional signal as input
on
(default) | off
Select this parameter to enable the Image input port for one multi-dimensional signal. If you select this parameter, the Separate Color Signals parameter clears automatically.
File > Configuration > Edit > Core
The Video Viewer Configuration parameters enable you to change the behavior and appearance of the graphic user interface (GUI).
To open the Configuration dialog box and edit parameters, select File > Configuration > Edit.
The Core tab in the Configuration dialog box lists the general settings of the GUI.
In the Core tab, select
General UI
item and click the Properties button to open the General UI Properties dialog box.
Display the full path — Display full path of source data in the title bar
off
(default) | on
Select this parameter to display the model name and full path to the source data in the title bar of the Video Viewer window. If you clear this parameter, the window displays a shortened name.
File > Configuration > Edit > Tools
The Video Viewer Configuration parameters enable you to change the behavior and appearance of the graphic user interface (GUI).
To open the Configuration dialog box and edit parameters, select File > Configuration > Edit.
The Tools tab in the Configuration dialog box lists the tools associated with the Video Viewer block.
In the Tools tab, select the
Image Viewer
item and click the Properties button to open the Image Viewer Properties dialog box.
Open new Image Viewer window for each export — Open new Image Viewer window for each exported video frame
on
(default) | off
Select this parameter to open a new Image Viewer window for each exported video frame or image in an image sequence.
Tools > Colormap
The Colormap parameters enable you to display an intensity image in various colormap formats and control the output intensity range. To access these parameters, select Tools > Colormap or press C.
Note
The Colormap parameters are available for intensity images only.
Colormap — Set colormap
gray(256)
(default) | parula(256)
| jet(256)
| hot(256)
| bone(256)
| cool(256)
| copper(256)
This parameter specifies the colormap in which to display the input intensity
image. This block supports the gray(256)
,
parula(256)
, jet(256)
,
hot(256)
, bone(256)
, and
copper(256)
colormaps.
Specify range of displayed pixel values [-Inf to Inf] — Specify range of intensity value to display
off
(default) | on
Select this parameter to enable the Min and Max parameters, through which you can specify the display range of pixel intensities.
Min — Minimum intensity value
0
(default) | numeric scalar
If a pixel has an intensity value less than or equal to the value of this parameter, Video Viewer displays it as the first color in the selected colormap.
Note
When specifying a value for Min, remember that the data type of the input image or video determines the range of intensity values representing that image or video.
Dependencies
To enable this parameter, select the Specify range of displayed pixel values [-Inf to Inf] parameter.
Max — Maximum intensity value
255
(default) | numeric scalar
If a pixel has an intensity value higher than or equal to the value of this parameter, Video Viewer displays it as the last color in the selected colormap.
Note
When specifying a value for Max, remember that the data type of the input image or video determines the range of intensity values representing that image or video.
Dependencies
To enable this parameter, select the Specify range of displayed pixel values [-Inf to Inf] parameter.
Simulation
To access this parameter, select the Simulation menu in the Video Viewer window.
Drop Frames to Improve Performance — Drop frame rate of input video signal
on
(default) | off
Select this parameter to reduce the frame rate of the input video signal to improve performance of the simulation. If you unselect this parameter, the block displays all the frames in the input video signal during simulation.
Block Characteristics
Data Types |
|
Direct Feedthrough |
|
Multidimensional Signals |
|
Variable-Size Signals |
|
Zero-Crossing Detection |
|
Version History
Introduced before R2006a
See Also
Blocks
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