External Display

NI Vision 2019 for LabVIEW Help

Edition Date: March 2019

Part Number: 370281AG-01

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Owning Palette: Vision Utilities
Requires: NI Vision Development Module

Use the External Display VIs to do the following in an external display window: display an image, get and set ROIs, manipulate the floating ROI tools window, configure an ROI constructor window, and set up and use an image browser.

Palette Object Description
IMAQ WindDraw

Displays an image in an image window. The image window appears automatically when the VI is executed. The default image window does not have scrollbars. You can add scrollbars by using the IMAQ WindSetup VI.

IMAQ WindClose

Closes an image window.

IMAQ WindShow

Shows or hides an image window.

IMAQ WindMove

Indicates and sets the position of an image window.

IMAQ WindSize

Indicates and sets the size of an image window. You also can use this VI to add or remove scrollbars for image windows and test for the presence of scrollbars in an image window.

IMAQ WindZoom 2

Obtains or modifies the status of the zoom factor. An image can be displayed using either a positive zoom factor, which represents the image larger than actual size, or a negative zoom factor, which represents the image smaller than actual size. When the size of the image window is smaller than the image displayed, use this VI to specify the position of the image that is centered in the image window.

IMAQ WindSetup

Configures the appearance and attributes of a window.

IMAQ WindDisplayMapping

Sets/gets the pixel mapping policy for displaying 16-bit images with an unspecified bit depth. Because 16-bit grayscale images cannot be displayed with their full resolution on 32-bit color displays using common video adapters limited to 8-bit resolution/per pixel/color, 16-bit images need to be mapped to the 8-bit range (0 to 255).

IMAQ GetPalette

Selects a display palette. Five predefined palettes are available. To activate a color palette, choose a code for Palette Number and connect the Color Palette output to the input Color Palette of the IMAQ WindDraw VI.

IMAQ ConstructROI

Allows the user to specify a region of interest (ROI) on the image. IMAQ ConstructROI displays the image in the specified window and provides the set of tools defined to select an ROI. IMAQ ConstructROI also returns the ROI descriptor that corresponds to the ROI drawn on the image when you click OK in the constructor window.


Returns the descriptor for an ROI.


Associates an ROI with an image window.


Erases the active region of interest associated with an image window.


Selects the color to use to depict ROI contours in the image window.

IMAQ WindLastEvent

Returns the events generated through the image windows as well as the data associated with them.

IMAQ WindGrid

Obtains or modifies the status of the grid. If enabled, the grid is invisible and drawn ROIs will be constrained to it. The grid can be used to help trace a region of interest accurately.

IMAQ WindBackground

Allows you to change the way the background of an image window is displayed.

IMAQ WindNonTearing

Allows you to configure the non-tearing functionality of a display window. Tearing images can occur when the image display rate is not synchronized with the refresh rate of the monitor. The difference between the display rate and the monitor refresh rate can cause parts of two different images to be displayed at the same time, which results in a split in the displayed image. By enabling non-tearing, the image display is synchronized to the refresh of the monitor and tearing is eliminated.

IMAQ WindToolsSetup

Configures the appearance and availability of the region tools found in the NI Vision Tools palette. With no input connections, the palette displays all nine region tools. The NI Vision Tools palette is a floating palette and is always visible.

IMAQ WindToolsSelect

Obtains or modifies the status of the region tools.

IMAQ WindToolsShow

Shows or hides the WindTools palette. This VI functions in the same way as the IMAQ WindShow VI, which is used for displaying image windows.

IMAQ WindToolsMove

Obtains or sets the position of the NI Vision Tools palette. This VI functions in the same way as the IMAQ WindMove VI, which is used for moving image windows.

IMAQ WindToolsClose

Closes the NI Vision Tools palette. This VI functions in the same way as the IMAQ WindClose VI, which is used for closing image windows.

Subpalette Description

Use the Browser VIs to create, configure, and use an image browser.


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