调节亮度、对比度及gamma值实现彩色图像的亮度变换

#include #include #include #include int ImageAdjust(IplImage* src, IplImage* dst, double low, double high, // X方向：low and high are the intensities of src double bottom, double top, // Y方向：mapped to bottom and top of dst double gamma ) { double low2 = low*255; double high2 = high*255; double bottom2 = bottom*255; double top2 = top*255; double err_in = high2 - low2; double err_out = top2 - bottom2; int x,y; double val; if(low<0 && low>1 && high <0 && high>1&& bottom<0 && bottom>1 && top<0 && top>1 && low>high) return -1; // intensity transform for( y = 0; y < src->height; y++) { for (x = 0; x < src->width; x++) { val = ((uchar*)(src->imageData + src->widthStep*y))[x]; val=pow((val - low2)/err_in, gamma)*err_out+bottom2; if(val>255) val=255; if(val<0) val=0; // Make sure src is in the range [low,high] ((uchar*)(dst->imageData + dst->widthStep*y))[x] = (uchar) val; } } return 0; } void main() { int i; IplImage *pImageChannel[4] = { 0, 0, 0, 0 }; IplImage* pSrcImage = cvLoadImage( "WeiShengZhiHuiZhongXin_Re-000000_00000000_00001465_00000119.jpg", 1 ) ; IplImage *pImage = cvCreateImage(cvGetSize(pSrcImage), pSrcImage->depth, pSrcImage->nChannels); if( pSrcImage ) { for( i = 0; i < pSrcImage->nChannels; i++ ) { pImageChannel[i] = cvCreateImage( cvGetSize(pSrcImage), pSrcImage->depth, 1 ); } // 信道分离 cvSplit( pSrcImage, pImageChannel[0], pImageChannel[1], pImageChannel[2], pImageChannel[3] ); for( i = 0; i < pImage->nChannels; i++ ) { // 直方图均衡化 //cvEqualizeHist( pImageChannel[i], pImageChannel[i] ); // 输入参数 [0,0.5] 和 [0.5,1], gamma=1 ImageAdjust( pImageChannel[i], pImageChannel[i], 0, 0.8, 0, 1, 1.2); } // 信道组合 cvMerge( pImageChannel[0], pImageChannel[1], pImageChannel[2], pImageChannel[3], pImage ); cvSaveImage("adjustImage.jpg", pImage); // ……图像显示代码（略） // 释放资源 for( i = 0; i < pSrcImage->nChannels; i++ ) { if ( pImageChannel[i] ) { cvReleaseImage( &pImageChannel[i] ); pImageChannel[i] = 0; } } cvReleaseImage( &pImage ); pImage = 0; } }