Developer Reference

  • 2020
  • 07/15/2020
  • Public Content
Contents

PyramidLayerDown

Creates a lower pyramid layer.

Syntax

IppStatus ippiPyramidLayerDown_<mod>(const Ipp<datatype>*
pSrc
, int
srcStep
, IppiSize
srcRoiSize
, Ipp<datatype>*
pDst
, int
dstStep
, IppiSize
dstRoiSize
, IppiPyramidDownState_<mod>*
pState
);
Supported values for
mod
:
8u_C1R
16u_C1R
32f_C1R
8u_C3R
16u_C3R
32f_C3R
Include Files
ippcv.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
,
ippi.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
,
ippi.lib
Parameters
pSrc
Pointer to the source image ROI.
srcStep
Distance, in bytes, between the starting points of consecutive lines in the source image.
srcRoiSize
Size of the source image ROI, in pixels.
pDst
Pointer to the destination image ROI.
dstStep
Distance, in bytes, between the starting points of consecutive lines in the destination image.
dstRoiSize
Size of the destination image ROI, in pixels.
pState
Pointer to the pyramid layer structure.
Description
This function operates with ROI (see Regions of Interest in Intel IPP ).
This function creates a lower pyramid layer
pDst
from the source image
pSrc
. The function applies the convolution kernel to the source image using the mirror border and then performs downsampling.
Before calling
ippiPyramidLayerDown
, compute the size of the
pState
structure and work buffer using the PyramidLayerDownGetSize function and initialize the structure using the PyramidLayerDownInit function. The function can process images with
srcRoiSize
not greater than the
srcRoi
parameter specified in the PyramidLayerDownInit function.
This function uses the mirrored border.
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error if one of the specified pointers is
NULL
.
ippStsSizeErr
Indicates an error condition if
srcRoiSize
or
dstRoiSize
has a field with zero or negative value.
ippStsStepErr
Indicates an error condition if
srcStep
is less than
srcRoiSize.width * <pixelSize>
, or
dstStep
is less than
dstRoiSize.width * <pixelSize>
.
ippStsNotEvenStepErr
Indicates an error condition if one of the step values is not divisible by 4 for floating-point images, or by 2 for short-integer images.
ippStsBadArgErr
Indicates an error condition if
pState->rate
has wrong value.

Example

/******************************************************************************* * Copyright 2015-2020 Intel Corporation. * * This software and the related documents are Intel copyrighted materials, and * your use of them is governed by the express license under which they were * provided to you (License). Unless the License provides otherwise, you may not * use, modify, copy, publish, distribute, disclose or transmit this software or * the related documents without Intel's prior written permission. * * This software and the related documents are provided as is, with no express * or implied warranties, other than those that are expressly stated in the * License. *******************************************************************************/ // A simple example of downsampling of the image with // 5x5 Gaussian kernel using Intel(R) Integrated Primitives (Intel(R) IPP) functions: // ippiPyramidGetSize // ippiPyramidInit // ippiPyramidLayerDownGetSize_32f_C1R // ippiPyramidLayerDownInit_32f_C1R // ippiPyramidLayerDown_32f_C1R #include <stdio.h> #include "ipp.h" #define WIDTH 128 /* Image width */ #define HEIGHT 128 /* Image height */ #define KERSIZE 3 /* Kernel size */ /* Next two defines are created to simplify code reading and understanding */ #define EXIT_MAIN exitLine: /* Label for Exit */ #define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) IPP function returned status different from ippStsNoErr */ /* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status */ int main(void) { IppStatus status = ippStsNoErr; Ipp32f* pSrc = NULL; /* Pointer to source image */ int srcStep; /* Step, in bytes, through the source image */ IppiSize roiSize = { WIDTH, HEIGHT }; /* Size of source/destination ROI in pixels */ Ipp32f rate = 2.f; /* Neighbor levels ratio */ int level = 1000; /* Maximal number pyramid level */ int i = 0; int pyrBufferSize = 0; int pyrStructSize = 0; IppiPyramid *pPyrStruct = NULL; Ipp8u *pPyrBuffer = NULL; Ipp8u *pPyrStrBuffer = NULL; int pyrLStateSize = 0; int pyrLBufferSize = 0; Ipp8u *pPyrLStateBuf = NULL; Ipp8u *pPyrLBuffer = NULL; Ipp32f **pPyrImage = NULL; Ipp32f kernel[KERSIZE] = { 1.f, 1.f, 1.f }; /* Separable symmetric kernel of odd length */ pSrc = ippiMalloc_32f_C1(roiSize.width, roiSize.height, &srcStep); /* Build Gaussian pyramid */ { /* Computes the temporary work buffer size */ check_sts( status = ippiPyramidGetSize(&pyrStructSize, &pyrBufferSize, level, roiSize, rate) ) pPyrBuffer = ippsMalloc_8u(pyrBufferSize); pPyrStrBuffer = ippsMalloc_8u(pyrStructSize); /* Initializes Gaussian structure for pyramids */ check_sts( status = ippiPyramidInit(&pPyrStruct, level, roiSize, rate, pPyrStrBuffer, pPyrBuffer) ) /* Correct maximum scale level */ level = pPyrStruct->level; /* Allocate structures to calculate pyramid layers */ check_sts( status = ippiPyramidLayerDownGetSize_32f_C1R(roiSize, rate, KERSIZE, &pyrLStateSize, &pyrLBufferSize) ) pPyrLStateBuf = ippsMalloc_8u(pyrLStateSize); pPyrLBuffer = ippsMalloc_8u(pyrLBufferSize); /* Initialize the structure for creating a lower pyramid layer */ check_sts( status = ippiPyramidLayerDownInit_32f_C1R((IppiPyramidDownState_32f_C1R**)&pPyrStruct->pState, roiSize, rate, kernel, KERSIZE, IPPI_INTER_LINEAR, pPyrLStateBuf, pPyrLBuffer) ) /* Allocate pyramid layers */ pPyrImage = (Ipp32f**)pPyrStruct->pImage; pPyrImage[0] = pSrc; pPyrStruct->pStep[0] = srcStep; for(i = 1; i <= level; i++) { pPyrImage[i] = ippiMalloc_32f_C1(pPyrStruct->pRoi[i].width, pPyrStruct->pRoi[i].height, &pPyrStruct->pStep[i]); } /* Perform downsampling of the image with 5x5 Gaussian kernel */ for(i = 1; i <= level; i++) { check_sts( status = ippiPyramidLayerDown_32f_C1R(pPyrImage[i - 1], pPyrStruct->pStep[i - 1], pPyrStruct->pRoi[i - 1], pPyrImage[i], pPyrStruct->pStep[i], pPyrStruct->pRoi[i], (IppiPyramidDownState_32f_C1R*)pPyrStruct->pState) ) } } EXIT_MAIN if (pPyrImage) for(i = 1; i <= level; i++) ippiFree(pPyrImage[i]); ippiFree(pPyrLStateBuf); ippiFree(pPyrLBuffer); ippiFree(pPyrStrBuffer); ippiFree(pPyrBuffer); ippiFree(pSrc); printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status)); return status; }

Product and Performance Information

1

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