Video Viewer

Display images or video frames

• Library:

• 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 Tool. Alternatively, select the Export to Image Tool 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.

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 Tool item and click the Properties button to open the Image Tool Properties dialog box.

Open new Image Tool 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.

Model 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.

Open Model

Pad Zeros to Image

Add rows and columns of zeros to an image by using a padding operation.

Open Model

Block Characteristics

Data Types	Boolean | double | integer | single
Direct Feedthrough	no
Multidimensional Signals	no
Variable-Size Signals	yes
Zero-Crossing Detection	no

Version History

Introduced before R2006a