clahe.rar_CLAHE_改进CLAHE_直方图 对比度

#include "StdAfx.h" #include "clahe.h" int CLAHE (kz_pixel_t* pImage, unsigned int uiXRes, unsigned int uiYRes, kz_pixel_t Min, kz_pixel_t Max, unsigned int uiNrX, unsigned int uiNrY, unsigned int uiNrBins, float fCliplimit) { unsigned int uiX, uiY; unsigned int uiXSize, uiYSize, uiSubX, uiSubY; unsigned int uiXL, uiXR, uiYU, uiYB; unsigned long ulClipLimit, ulNrPixels; kz_pixel_t* pImPointer; kz_pixel_t aLUT[uiNR_OF_GREY]; unsigned long* pulHist, *pulMapArray; unsigned long* pulLU, *pulLB, *pulRU, *pulRB; if (uiNrX > uiMAX_REG_X) return -1; if (uiNrY > uiMAX_REG_Y) return -2; if (Max >= uiNR_OF_GREY) return -5; if (Min >= Max) return -6; if (uiNrX < 2 || uiNrY < 2) return -7; if (fCliplimit == 1.0) return 0; if (uiNrBins == 0) uiNrBins = 128; pulMapArray=(unsigned long *)malloc(sizeof(unsigned long)*uiNrX*uiNrY*uiNrBins); if (pulMapArray == 0) return -8; uiXSize = uiXRes/uiNrX; uiYSize = uiYRes/uiNrY; ulNrPixels = (unsigned long)uiXSize * (unsigned long)uiYSize; if(fCliplimit > 0.0) { ulClipLimit = (unsigned long) (fCliplimit * (uiXSize * uiYSize) / uiNrBins); ulClipLimit = (ulClipLimit < 1UL) ? 1UL : ulClipLimit; } else ulClipLimit = 1UL<<14; MakeLut(aLUT, Min, Max, uiNrBins); for (uiY = 0, pImPointer = pImage; uiY < uiNrY; uiY++) { for (uiX = 0; uiX < uiNrX; uiX++, pImPointer += uiXSize) { pulHist = &pulMapArray[uiNrBins * (uiY * uiNrX + uiX)]; MakeHistogram(pImPointer,uiXRes,uiXSize,uiYSize,pulHist,uiNrBins,aLUT); ClipHistogram(pulHist, uiNrBins, ulClipLimit); MapHistogram(pulHist, Min, Max, uiNrBins, ulNrPixels); } pImPointer += (uiYSize - 1) * uiXRes; } for (pImPointer = pImage, uiY = 0; uiY <= uiNrY; uiY++) { if (uiY == 0) { uiSubY = uiYSize >> 1; uiYU = 0; uiYB = 0; } else { if (uiY == uiNrY) { uiSubY = uiYSize >> 1; uiYU = uiNrY-1; uiYB = uiYU; } else { uiSubY = uiYSize; uiYU = uiY - 1; uiYB = uiYU + 1; } } for (uiX = 0; uiX <= uiNrX; uiX++) { if (uiX == 0) { uiSubX = uiXSize >> 1; uiXL = 0; uiXR = 0; } else { if (uiX == uiNrX) { uiSubX = uiXSize >> 1; uiXL = uiNrX - 1; uiXR = uiXL; } else { uiSubX = uiXSize; uiXL = uiX - 1; uiXR = uiXL + 1; } } pulLU = &pulMapArray[uiNrBins * (uiYU * uiNrX + uiXL)]; pulRU = &pulMapArray[uiNrBins * (uiYU * uiNrX + uiXR)]; pulLB = &pulMapArray[uiNrBins * (uiYB * uiNrX + uiXL)]; pulRB = &pulMapArray[uiNrBins * (uiYB * uiNrX + uiXR)]; Interpolate(pImPointer,uiXRes,pulLU,pulRU,pulLB,pulRB,uiSubX,uiSubY,aLUT); pImPointer += uiSubX; } pImPointer += (uiSubY - 1) * uiXRes; } free(pulMapArray); return 0; } void ClipHistogram (unsigned long* pulHistogram, unsigned int uiNrGreylevels, unsigned long ulClipLimit) { unsigned long* pulBinPointer, *pulEndPointer, *pulHisto; unsigned long ulNrExcess, ulOldNrExcess, ulUpper, ulBinIncr, ulStepSize, i; long lBinExcess; ulNrExcess = 0; pulBinPointer = pulHistogram; for (i = 0; i < uiNrGreylevels; i++) { lBinExcess = (long) pulBinPointer[i] - (long) ulClipLimit; if (lBinExcess > 0) ulNrExcess += lBinExcess; }; ulBinIncr = ulNrExcess / uiNrGreylevels; ulUpper = ulClipLimit - ulBinIncr; for (i = 0; i < uiNrGreylevels; i++) { if (pulHistogram[i] > ulClipLimit) pulHistogram[i] = ulClipLimit; else { if (pulHistogram[i] > ulUpper) { ulNrExcess -= (pulHistogram[i] - ulUpper); pulHistogram[i]=ulClipLimit; //原算法 // ulNrExcess -= (ulClipLimit -pulHistogram[i]); pulHistogram[i]=ulClipLimit; //更改算法 } else { ulNrExcess -= ulBinIncr; pulHistogram[i] += ulBinIncr; } } } do { pulEndPointer = &pulHistogram[uiNrGreylevels]; pulHisto = pulHistogram; ulOldNrExcess = ulNrExcess; while (ulNrExcess && pulHisto < pulEndPointer) { ulStepSize = uiNrGreylevels / ulNrExcess; if (ulStepSize < 1) ulStepSize = 1; for (pulBinPointer=pulHisto; pulBinPointer < pulEndPointer && ulNrExcess; pulBinPointer += ulStepSize) { if (*pulBinPointer < ulClipLimit) { (*pulBinPointer)++; ulNrExcess--; } } pulHisto++; } } while ((ulNrExcess) && (ulNrExcess < ulOldNrExcess)); } void MakeHistogram (kz_pixel_t* pImage, unsigned int uiXRes, unsigned int uiSizeX, unsigned int uiSizeY, unsigned long* pulHistogram, unsigned int uiNrGreylevels, kz_pixel_t* pLookupTable) { kz_pixel_t* pImagePointer; unsigned int i; for (i = 0; i < uiNrGreylevels; i++) pulHistogram[i] = 0L; for (i = 0; i < uiSizeY; i++) { pImagePointer = &pImage[uiSizeX]; while (pImage < pImagePointer) pulHistogram[pLookupTable[*pImage++]]++; pImagePointer += uiXRes; pImage = pImagePointer-uiSizeX; } } void MapHistogram (unsigned long* pulHistogram, kz_pixel_t Min, kz_pixel_t Max, unsigned int uiNrGreylevels, unsigned long ulNrOfPixels) { unsigned int i; unsigned long ulSum = 0; const float fScale = ((float)(Max - Min)) / ulNrOfPixels; const unsigned long ulMin = (unsigned long) Min; for (i = 0; i < uiNrGreylevels; i++) { ulSum += pulHistogram[i]; pulHistogram[i]=(unsigned long)(ulMin+ulSum*fScale); if (pulHistogram[i] > Max) pulHistogram[i] = Max; } } void MakeLut (kz_pixel_t * pLUT, kz_pixel_t Min, kz_pixel_t Max, unsigned int uiNrBins) { int i; const kz_pixel_t BinSize = (kz_pixel_t) (1 + (Max - Min) / uiNrBins); for (i = Min; i <= Max; i++) pLUT[i] = (i - Min) / BinSize; } void Interpolate (kz_pixel_t * pImage, int uiXRes, unsigned long * pulMapLU, unsigned long * pulMapRU, unsigned long * pulMapLB, unsigned long * pulMapRB, unsigned int uiXSize, unsigned int uiYSize, kz_pixel_t * pLUT) { const unsigned int uiIncr = uiXRes-uiXSize; kz_pixel_t GreyValue; unsigned int uiNum = uiXSize*uiYSize; unsigned int uiXCoef, uiYCoef, uiXInvCoef, uiYInvCoef, uiShift = 0; if (uiNum & (uiNum - 1)) for (uiYCoef = 0, uiYInvCoef = uiYSize; uiYCoef < uiYSize; ui