Reading a file, Converting an array to an image, Display an image – National Instruments IMAQTM User Manual

Page 23: Display an image -6

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Chapter 2

Getting Measurement-Ready Images

IMAQ Vision for Visual Basic User Manual

2-6

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Private Sub Stop_Click()

CWIMAQ1.Stop

End Sub

Reading a File

Use the

CWIMAQVision.ReadImage

method to open and read data from

a file stored on the computer into the image reference. You can read from
image files stored in several standard formats, such as BMP, TIFF, JPEG,
PNG, and AIPD. In all cases, the software automatically converts the pixels
it reads into the type of image you pass in.

Use the

CWIMAQVision.ReadImageAndVisionInfo

method to open an

image file containing additional information, such as calibration
information, template information for pattern matching, or overlay
information. For more information about pattern matching templates
and overlays, refer to Chapter 5,

Performing Machine Vision Tasks

.

You also can use the

CWIMAQVision.GetFileInformation

method

to retrieve image properties—image size, pixel depth, recommended image
type, and calibration units—without actually reading all the image data.

Converting an Array to an Image

Use the

CWIMAQImage.ArrayToImage

method to convert an array to an

image. You also can use the

CWIMAQImage.ImageToArray

method to

convert an image to an array.

Display an Image

Display an image using the CWIMAQViewer control. Use

CWIMAQViewer.Attach

to attach the image you want the viewer

to display. When you attach an image to a viewer, the image automatically
updates the viewer whenever an operation modifies the contents of the
image. You can access the image attached to the viewer using the

CWIMAQViewer.Image

property. Before you attach an image to the

viewer, the viewer already has an image attached by default. Therefore, the
viewer has an image attached to it at all times. You can use the attached
image as either a source image, destination image, or both using the

CWIMAQViewer.Image

property.

You can use the

CWIMAQViewer.Palette

property to access the

CWIMAQPalette object associated with the viewer. Use the
CWIMAQPalette object to programmatically apply a color palette to

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