computes the complex accumulator matrix used by the Hough circles detector ("gradient phase-coded" method) More...

IPSDKIPLFEATUREDETECTION_API HoughCirclesComplexImg	ipsdk::imaproc::fd::houghCirclesPhaseCoded2dImg (const image::ImageConstPtr &pInGxImg, const image::ImageConstPtr &pInGyImg, const ipsdk::imaproc::attr::HoughCirclesRadiusRangeConstPtr &pRadiusRange)
	wrapper function for detects circles in images of gradient using Hough algorithm More...

IPSDKIPLFEATUREDETECTION_API void	ipsdk::imaproc::fd::houghCirclesPhaseCoded2dImg (const image::ImageConstPtr &pInGxImg, const image::ImageConstPtr &pInGyImg, const ipsdk::imaproc::attr::HoughCirclesRadiusRangeConstPtr &pRadiusRange, const ipsdk::imaproc::attr::eCircleIntensityType &eCircleIntensityType, const ipReal64 maxAngleWithGradDir, const ipUInt32 nbMaxPtsPerCircle, const image::ImagePtr &pOutRealImg, const image::ImagePtr &pOutImImg)
	wrapper function for detects circles in images of gradient using Hough algorithm More...

Detailed Description

computes the complex accumulator matrix used by the Hough circles detector ("gradient phase-coded" method)

This algorithm computes, from the 2 gradient images (respectively along x and y axis) of the same grey levels 2d image, the complex accumulator matrix used to detect circles in an image, using Hough algorithm ("gradient phase-coded" method).

See Hough circles detection for more information.

Below is an example of image returned by the algorithm on gradient images computed from an image of coins:

Attributes description

Attribute description for algorithm :

Name	ToolTip	Default Initializer
ipsdk::imaproc::attr::InGxGreyImg2d	[Input] 2d grey levels image of gradient computed along x-axis	X
ipsdk::imaproc::attr::InGyGreyImg2d	[Input] 2d grey levels image of gradient computed along y-axis	X
ipsdk::imaproc::attr::InOptCircleIntensityType	[Input Optional] circle intensity type for detection algorithms	X
ipsdk::imaproc::attr::InOptMaxAngleWithGradDir	[Input Optional] maximum angle with gradient direction, in radians	X
ipsdk::imaproc::attr::InOptNbMaxPtsPerCircle	[Input Optional] maximum number of points per circle	X
ipsdk::imaproc::attr::InOptHoughCirclesRadiusRange	[Input Optional] range of radius of circles to detect using Hough circles algorithm	X
ipsdk::imaproc::attr::OutComplexRealImg	[Output Optional] Real part of the complex image resulting from Hough circles detection	ipsdk::imaproc::duplicateInOut (_pOutComplexRealImg, _pInGxGreyImg2d, ipsdk::image::eImageBufferType::eIBT_Real32)
ipsdk::imaproc::attr::OutComplexImImg	[Output Optional] Imaginary part of the complex image resulting from Hough circles detection	ipsdk::imaproc::duplicateInOut (_pOutComplexImImg, _pInGxGreyImg2d, ipsdk::image::eImageBufferType::eIBT_Real32)

Global Rule description

Global rule description for algorithm :
ipsdk::imaproc::matchSizeAndType (_pInGxGreyImg2d,_pInGyGreyImg2d) &&
ipsdk::imaproc::matchSize (_pInGxGreyImg2d,_pOutComplexRealImg,_pOutComplexImImg) &&
ipsdk::imaproc::matchSizeAndType (_pOutComplexRealImg,_pOutComplexImImg) && ipsdk::imaproc::matchSize<ipsdk::imaproc::attr::HoughCirclesRadiusRange::MaxRadius>(ipsdk::imaproc::eMatchImageSizeType::eMIST_2d,ipsdk::imaproc::eMatchImageSizeScale::eMISS_HalfSize,_pInGxGreyImg2d,_pInOptHoughCirclesRadiusRange)

Example of Python code :

Example imports

import PyIPSDK
import PyIPSDK.IPSDKIPLFeatureDetection as fd
import PyIPSDK.IPSDKIPLFiltering as filter

Code Example

    # opening of input image
    inImg = PyIPSDK.loadTiffImageFile(inputImgPath)
    
    # associated gradient images computation
    gxImg,  gyImg = filter.gaussianGradient2dImg(inImg,  1.0)
    
    # radius range detection definition
    radiusRange = PyIPSDK.createHoughCirclesRadiusRange(15,  20)
    
    # hough circle phase coded detection computation
    outRealImg,  outImImg = fd.houghCirclesPhaseCoded2dImg(gxImg,  gyImg,  radiusRange)

Example of C++ code :

Example informations

Associated library

IPSDKIPLFeatureDetection

Header file

#include <IPSDKIPL/IPSDKIPLFeatureDetection/Processor/HoughCirclesPhaseCoded2dImg/HoughCirclesPhaseCoded2dImg.h>

Code Example

#include <IPSDKImage/Geometry/ImageGeometryInstances.h>
#include <IPSDKImage/Image/Memory/MemoryImage.h>
#include <IPSDKImageFile/Tiff/TiffImageFileUtils.h>
#include <IPSDKIPL/IPSDKIPLFeatureDetection/Processor/HoughCirclesPhaseCoded2dImg/HoughCirclesPhaseCoded2dImg.h>
#include <utility>
// function returning the complex accumulation image (one image for real part
// + one image for imaginary part) used by Hough circle detector 
// ("gradient phase-coded" method) applied on an input image loaded from a given
// file to detect circles of radii belonging to a given range
std::pair<ipsdk::image::ImagePtr, ipsdk::image::ImagePtr>
computeHoughCirclesPhaseCoded2dImages(
    const std::string& inImgFilePath,
    ipUInt64 nMinRadius,
    ipUInt64 nMaxRadius)
{
    // load input image from file specified by the user
    ipsdk::image::ImagePtr pInImg =
        ipsdk::image::file::loadTiffImageFile(inImgFilePath);
    // compute gradient images, in x and y
    GradientXYImg gxyImg =
        gaussianGradient2dImg(pInImg, 1.0f, 1.0f, createGaussianCoverage(0.997f, 2));
    ImagePtr pInGxImg = gxyImg._pXGradImg;
    ImagePtr pInGyImg = gxyImg._pYGradImg;
    // apply Hough circles detection on gradient images
    HoughCirclesComplexImg hcComplexImg =
    ipsdk::imaproc::fd::houghCirclesPhaseCoded2dImg(
        pInGxImg,
        pInGyImg,
        ipsdk::imaproc::attr::createHoughCirclesRadiusRange(nMinRadius, nMaxRadius));
    // return the accumulation image
    return std::make_pair(hcComplexImg._pRealImg, hcComplexImg._pImImg);
}

See also: HoughCirclesPhaseCoded2dImgLvl1; HoughCirclesPhaseCoded2dImgLvl2; HoughCirclesPhaseCoded2dImgLvl3

Function Documentation

◆ houghCirclesPhaseCoded2dImg() [1/2]

IPSDKIPLFEATUREDETECTION_API HoughCirclesComplexImg ipsdk::imaproc::fd::houghCirclesPhaseCoded2dImg	(	const image::ImageConstPtr &	pInGxImg,
		const image::ImageConstPtr &	pInGyImg,
		const ipsdk::imaproc::attr::HoughCirclesRadiusRangeConstPtr &	pRadiusRange
	)

wrapper function for detects circles in images of gradient using Hough algorithm

Exceptions

ipsdk::processor::IPSDKBaseProcessingException on failure

◆ houghCirclesPhaseCoded2dImg() [2/2]

IPSDKIPLFEATUREDETECTION_API void ipsdk::imaproc::fd::houghCirclesPhaseCoded2dImg	(	const image::ImageConstPtr &	pInGxImg,
		const image::ImageConstPtr &	pInGyImg,
		const ipsdk::imaproc::attr::HoughCirclesRadiusRangeConstPtr &	pRadiusRange,
		const ipsdk::imaproc::attr::eCircleIntensityType &	eCircleIntensityType,
		const ipReal64	maxAngleWithGradDir,
		const ipUInt32	nbMaxPtsPerCircle,
		const image::ImagePtr &	pOutRealImg,
		const image::ImagePtr &	pOutImImg
	)

wrapper function for detects circles in images of gradient using Hough algorithm

Exceptions

ipsdk::processor::IPSDKBaseProcessingException on failure