Visible to Intel only — GUID: GUID-C12712A9-9D9D-4FDB-B308-60747F4300B1
Visible to Intel only — GUID: GUID-C12712A9-9D9D-4FDB-B308-60747F4300B1
ComputeThreshold_Otsu
Computes the value of the Otsu threshold.
Syntax
IppStatus ippiComputeThreshold_Otsu_8u_C1R(const Ipp8u* pSrc, int srcStep, IppiSize roiSize, Ipp8u* pThreshold);
Include Files
ippi.h
Domain Dependencies
Headers: ippcore.h, ippvm.h, ipps.h
Libraries: ippcore.lib, ippvm.lib, ipps.lib
Parameters
pSrc |
Pointer to the source image ROI. |
srcStep |
Distance in bytes between starts of consecutive lines in the source image. |
roiSize |
Size of the image ROI in pixels. |
pThreshold |
Pointer to the Otsu threshold value. |
Description
This function operates with ROI (see Regions of Interest in Intel IPP).
This function calculates the Otsu threshold ([Otsu79]) for the source image pSrc in accordance with the following formula:
where 0 ≤x < roiSize.width, 0 ≤y < roiSize.height, and T is the Otsu threshold.
where
The computed Otsu threshold can be used in the thresholding functions described above.
For example, the following figures shows how the Otsu threshold can be used for background/foreground selection. The figure a) below shows the initial image, the figure b) shows the histogram of the initial image with the red line indicating the computed Otsu threshold. The figure c) demonstrates the resulting image obtained by applying the function ippiThreshold_8u_C1R with a computed Otsu threshold value to the source image.
Return Values
ippStsNoErr |
Indicates no error. Any other value indicates an error. |
ippStsNullPtrErr |
Indicates an error condition if one of the specified pointer is NULL. |
ippStsSizeErr |
Indicates an error condition if roiSize has a field with zero or negative value. |
ippStsStepErr |
Indicates an error condition if srcStep is less than or equal to 0. |