imaqLearnCalibrationGrid
Usage
int imaqLearnCalibrationGrid(Image* image, const ROI* roi, const LearnCalibrationOptions* options, const GridDescriptor* grid, const CoordinateSystem* system, const RangeFloat* range, float* quality);
Purpose
Learns a calibration from an image of a grid of circles. The function attaches calibration information to the grid image, which you can then use with imaqCopyCalibrationInfo2() to calibrate an uncalibrated image. Refer to Chapter 6, Calibrating Images, of the NI Vision for LabWindows/CVI User Manual. for more information about creating a grid image.
Image Types Supported
IMAQ_IMAGE_U8, IMAQ_IMAGE_I16
Parameters
|
Name
|
Type
|
Description
|
|---|---|---|
| image | Image* | The template used for calibrating your system. It should be an image of a grid of circles. |
| roi | const ROI* | Determines the region of the image that the function uses in the learning process. The function ignores all the circles in the grid that are outside the defined region when estimating the calibration transformation. To learn the entire image, set this parameter to NULL. |
| options | const LearnCalibrationOptions* | Describes how the function learns the calibration information. |
| grid | const GridDescriptor* | Contains scaling constants for the grid image that the function uses to learn the calibration. |
| system | const CoordinateSystem* | Defines the coordinate system for real world coordinates. |
| range | const RangeFloat* | The range of the grayscale the function uses to represent the circles in the grid image. |
| quality | float* | On return, the quality score of the learning process, which is a value between 0-1000. A quality of 1000 means that the function learned the feature points perfectly with the chosen algorithm. It does not necessarily reflect the absolute accuracy of the estimated calibration mapping, but instead reflects how well the calibration mapping adapts to the learned grid. Set this parameter to NULL if you do not need this information. |
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
options—Set options to NULL to use the default options, as follows:
| mode | IMAQ_PERSPECTIVE |
| method | IMAQ_SCALE_TO_PRESERVE_AREA |
| roi | IMAQ_USER_ROI |
| learnMap | FALSE |
| learnTable | FALSE |
grid—Set grid to NULL to use the following default scaling constants:
| xStep | 1 |
| yStep | 1 |
| unit | IMAQ_UNDEFINED |
system—Set system to NULL to use the following default coordinate system:
| origin | {0, 0} |
| angle | 0 |
| axisOrientation | IMAQ_INDIRECT |
range—Set the range parameter to NULL to use the default range, as follows:
| minValue | 0 |
| maxValue | 180 |