corrects an input image for shading More...

IPSDKIPLINTENSITYTRANSFORM_API ipsdk::image::ImagePtr	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 factor)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API void	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 factor, const ipsdk::image::ImagePtr &pOutImg)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API ipsdk::image::ImagePtr	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pBlackImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 factor)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API void	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pBlackImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 factor, const ipsdk::image::ImagePtr &pOutImg)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API ipsdk::image::ImagePtr	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 offset, const ipReal64 factor)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API void	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 offset, const ipReal64 factor, const ipsdk::image::ImagePtr &pOutImg)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API ipsdk::image::ImagePtr	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pBlackImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 offset, const ipReal64 factor)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

IPSDKIPLINTENSITYTRANSFORM_API void	ipsdk::imaproc::itrans::shadingCorrectionImg (const image::ImageConstPtr &pInImg, const image::ImageConstPtr &pBlackImg, const image::ImageConstPtr &pWhiteImg, const ipReal64 offset, const ipReal64 factor, const ipsdk::image::ImagePtr &pOutImg)
	wrapper function for Computes a shading-corrected image given in particular an offset and a factor More...

Detailed Description

corrects an input image for shading

Corrects an input image for shading that may be introduced during its acquisition.

Given:

an input image
a white and an optional black image, and , whose dimensions and data types are identical to input image dimensions and data types
a scalar offset
a scalar factor

Values of output image resulting from shading correction are computed as follows:

$OutImg[i] = \begin{cases} offset + factor.{\dfrac {InImg[i]-BlackImg[i]} {WhiteImg[i]-BlackImg[i]}} & \text { if } WhiteImg[i]-BlackImg[i] \ne 0 \\ offset & \text { otherwise} \end{cases}$

Here is an example of shading correction applied to a 8-bits grey level image on which an artificial vignetting has been applied:

Attributes description

Attribute description for algorithm :

Name	ToolTip	Default Initializer
ipsdk::imaproc::attr::InImg	[Input] image for processing operation	X
ipsdk::imaproc::attr::InOptBlackImg	[Input Optional] Black image, usually obtained by closing all optical ports of the camera, or by turning off all the light sources. Used by shading correction algorithm	X
ipsdk::imaproc::attr::InWhiteImg	[Input] White image. Used by shading correction algorithm	X
ipsdk::imaproc::attr::InOptOffset	[Input Optional] Offset. Used for instance by shading correction algorithm	X
ipsdk::imaproc::attr::InFactor	[Input] Multiplying factor. Used for instance by shading correction algorithm	X
ipsdk::imaproc::attr::OutImg	[Output] image for processing operation	ipsdk::imaproc::duplicateInOut (_pOutImg, _pInImg)

Global Rule description

Global rule description for algorithm :
ipsdk::imaproc::matchSize (_pInImg,_pOutImg) &&
ipsdk::processor::ifIsSet (_pInOptBlackImg,
ipsdk::imaproc::matchSizeAndType (_pInImg,_pInOptBlackImg)) &&
ipsdk::imaproc::matchSizeAndType (_pInImg,_pInWhiteImg)

Example of Python code :

Example imports

import PyIPSDK
import PyIPSDK.IPSDKIPLIntensityTransform as itrans
import PyIPSDK.IPSDKIPLFiltering as filter

Code Example

    # opening of input image
    inImg = PyIPSDK.loadTiffImageFile(inputImgPath)
    
    # opening of white image
    # note : could also be created with operation such as 'whiteImg = filter.meanSmoothing2dImg(inImg, 50, 50)'
    whiteImg = PyIPSDK.loadTiffImageFile(whiteImgPath)
    
    # image shading correction computation
    outImg = itrans.shadingCorrectionImg(inImg,  whiteImg,  200)

Example of C++ code :

Example informations

Associated library

IPSDKIPLIntensityTransform

Header file

#include <IPSDKIPL/IPSDKIPLIntensityTransform/Processor/ShadingCorrectionImg/ShadingCorrectionImg.h>

Code Example

            // Sample with a generated output image
            // -----------------------------------
            ImagePtr pAutoOutImg;
            if(!pBlackImg)
                pAutoOutImg = shadingCorrectionImg(pInImg, pWhiteImg, factor);
            else
                pAutoOutImg = shadingCorrectionImg(pInImg, pBlackImg, pWhiteImg, factor);

See also: ShadingCorrectionImgLvl1; ShadingCorrectionImgLvl2; ShadingCorrectionImgLvl3