Detects straight lines with the specified range of parameters in the source image.
Syntax
IppStatus ippiHoughLine_Region_8u32f_C1R(const Ipp8u* pSrc, int srcStep, IppiSize roiSize, IppPointPolar* pLine, IppPointPolar dstRoi[2], int maxLineCount, int* pLineCount, IppPointPolar delta, int threshold, Ipp8u* pBuffer);
Parameters
- pSrc
- Pointer to the source image ROI.
- srcStep
- Distance in bytes between starts of consecutive lines in the source image.
- roiSize
- Size of source image ROI in pixels.
- pLine
- Pointer to the destination array of detected lines.
- dstRoi
- Specifies the range of parameters of straight lines to be detected.
- pLineCount
- Pointer to the number of detected lines.
- delta
- Step of discretization ( delta.rho - radial increment, delta.theta - angular increment).
- threshold
- Minimum number of points that are required to detect the line.
- maxLineCount
- Maximum number of lines in the destination buffer.
- pBuffer
- Pointer to the working buffer.
Description
The function ippiHoughLine_Region is declared in the ippcv.h file. It operates with ROI (see Regions of Interest in Intel IPP).
In the binarised source image pSrc, this function performs detection of the straight line defined by the equation given at the beginning of section Hough Transform. Only lines line[n] with the parameters satisfying the following conditions are detected:
dstRoi[0].rho ≤ line [n].rho ≤ dstRoi[1]. rho;
dstRoi[0]. theta ≤ line[n].theta ≤ dstRoi [1].theta;
where n = 0. pLineCount.
The level of discretization delta is specified as the input parameters. The performance and effectiveness of the function is strongly depends on this parameter. The function requires the external working buffer pBuffer whose size should be computed previously using the function ippiHoughLineGetSize.
Caution
The value of the parameter delta must not be greater than the value of the parameter delta set when the size of the working buffer is computed.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error if one of the specified pointers is NULL. |
ippStsSizeErr |
Indicates an error condition if roiSize has a field with zero or negative value; or if maxLineCount is less than or equal to 0. |
ippStsStepErr |
Indicates an error condition if srcStep has an illegal value. |
ippStsBadArgErr |
Indicates an error condition if threshold is less than or equal to 0; or delta.rho is less than 0, or greater than sum of the width and height of the ROI; or delta.theta is less than 0, or greater than p; or some filed of dstRoi[0] is greater than the corresponding filed of dstRoi[1]. |
ippStsDstSizeLessExpected |
Indicates a warning if number of the detected lines is greater thean the size of the destination buffer maxLineCount. |