IMAQ ColorHistograph VI

LabView NI Vision

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IMAQ ColorHistograph VI

Owning Palette: Color ProcessingInstalled With: NI Vision Development Module

Calculates the histograms extracted from the three planes of an image. This VI can function in one of four modes corresponding to the color models RGB, HSL, HSV, and HSI. The output from this VI is directly compatible with a LabVIEW graph.

IMAQ ColorHistograph

Color Mode defines the image color format to use for the operation. Choose from the following values:

RGB (0)	(Default) Specifies the color format RGB (red, green, and blue)
HSL (1)	Specifies the color format HSI (hue, saturation, and luminance)
HSV (2)	Specifies the color format HSV (hue, saturation, and value)
HSI (3)	Specifies the color format HSI (hue, saturation, and intensity)

Image Src is a reference to the source image.

Image Mask is an 8-bit image specifying the region in the image to use for the calculation. Only those pixels in the original image that correspond to an equivalent non-zero pixel in the mask image are used for the calculation. The entire image is used in the calculation if Image Mask is not connected.

Number of Classes specifies the number of classes used to classify the pixels. The default value is 256.

error in (no error) describes the error status before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

	status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

Red or Hue Histogram Graph is a cluster that returns the detailed results from a histogram calculated on a red or hue plane, depending on the Color Mode. This cluster is the same as the cluster used by the IMAQ Histograph VI. It contains the following elements:

	Starting Value is always equal to 0. This parameter is returned in the type Histogram Report, as in the IMAQ Histograph VI.
	Incremental Value returns the incrementing value that specifies how much to add to Starting Value in calculating the median value of each class from the histogram. The median value x _n from the nth class is expressed as follows: x _n = Starting Value + n × Incremental Value.
	Histogram returns the histogram values in an array. The elements found in this array are the number of pixels per class. The nth class contains all pixel values belonging to the interval [(Starting Value + (n – 1) × Interval Width), (Starting Value + n × (Interval Width – 1))].

Green or Sat Histogram Graph is a cluster that returns the detailed results from a histogram calculated on the green or saturation plane, depending on the Color Mode. This cluster is the same as the cluster used by the IMAQ Histograph VI. It contains the following elements:

	Starting Value is always equal to 0. This parameter is returned in the type Histogram Report, as in the IMAQ Histograph VI.
	Incremental Value returns the incrementing value that specifies how much to add to Starting Value in calculating the median value of each class from the histogram. The median value x _n from the nth class is expressed as follows: x _n = Starting Value + n × Incremental Value.
	Histogram returns the histogram values in an array. The elements found in this array are the number of pixels per class. The nth class contains all pixel values belonging to the interval [(Starting Value + (n – 1) × Interval Width), (Starting Value + n × (Interval Width – 1))].

Blue or Luma or Val or Inten Histogram Graph is a cluster that returns the detailed results from a histogram calculated on the blue, luminance, value, or intensity planes, depending on the Color Mode. This cluster is the same as the cluster used by the IMAQ Histograph VI. It contains the following elements:

	Starting Value is always equal to 0. This parameter is returned in the type Histogram Report, as in the IMAQ Histograph VI.
	Incremental Value returns the incrementing value that specifies how much to add to Starting Value in calculating the median value of each class from the histogram. The median value x _n from the nth class is expressed as follows: x _n = Starting Value + n × Incremental Value.
	Histogram returns the histogram values in an array. The elements found in this array are the number of pixels per class. The nth class contains all pixel values belonging to the interval [(Starting Value + (n – 1) × Interval Width), (Starting Value + n × (Interval Width – 1))].

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

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