imaqLearnGeometricPattern
Usage
int imaqLearnGeometricPattern(Image* image, PointFloat originOffset, const CurveOptions* curveOptions, const LearnGeometricPatternAdvancedOptions* advancedLearnOptions, const Image* mask);
Purpose
Creates a description of the template image you want to search for during the matching phase.
Image Types Supported
IMAQ_IMAGE_U8
Parameters
|
Name
|
Type
|
Description
|
|---|---|---|
| image | Image* | The image about which the function learns pattern matching information. The function appends the pattern matching information to this image. |
| originOffset | PointFloat | Specifies the number of pixels the function shifts the origin of the template from the center of the template image. The origin of the template is used by imaqMatchGeometricPattern() to set the position element of the resulting GeometricPatternMatch struct for each template match within a target image. Set this parameter to IMAQ_NO_OFFSET to use the center of the template image as the origin of the template. |
| curveOptions | const CurveOptions* | Describes how the function identifies the curves in the image the function will use to create the template image. This function does not support identifying curves with subpixel accuracy and therefore ignores the subpixelAccuracy element of this parameter. |
| advancedLearnOptions | const LearnGeometricPatternAdvancedOptions* | Advanced options for determining the information the algorithm learns about the geometric pattern. |
| mask | const Image* | An optional image, which is the same size as the template, that specifies where to search for curves in the template. mask must be an IMAQ_IMAGE_U8 image. To allow the function to process all of the pixels to determine if the pixels contain curves, set this parameter to NULL. |
Return Value
| Type |
Description |
|---|---|
| int | On success, this function returns a non-zero value. On failure, this function returns 0. To get extended error information, call imaqGetLastError(). |
Parameter Discussion
curveOptions—Set curveOptions to NULL to use the default curve options, as follows:
| extractionMode | IMAQ_NORMAL_IMAGE |
| threshold | 75 |
| filterSize | IMAQ_NORMAL |
| minLength | 25 |
| rowStepSize | 15 |
| columnStepSize | 15 |
| maxEndPointGap | 10 |
| onlyClosed | FALSE |
| subpixelAccuracy | FALSE |
advancedLearnOptions—Set advancedLearnOptions to NULL to use the default advanced learning options, as follows:
| minRectLength | 10 |
| minRectAspectRatio | 0.2 |
| minRadius | 5 |
| minLineLength | 15 |
| minFeatureStrength | 0.5 |
| maxFeaturesUsed | 25 |
| maxPixelDistanceFromLine | 2 |
mask—Use one or more of the following pixel values when constructing the mask:
0–Maintains the default behavior. The corresponding pixel in the template image is considered part of a curve only if it meets the conditions specified by curveOptions.
1–The corresponding pixel in the template image is never considered part of a curve.
2–The corresponding pixel in the template image is always considered part of a curve.
4–The corresponding pixel in the template image is not used by imaqMatchGeometricPattern() when computing the correlationScore returned for each match. You can combine this pixel value with values 1 or 2 to control both the curve detection and scoring for the corresponding pixel.