#include <cv.h>
#include <highgui.h>#include <iostream>using namespace std;float Abs(float f);
void zoom(IplImage* src, IplImage* dst);int main() {// read an imageIplImage* src = cvLoadImage("E://pic//view.jpg");IplImage* dst = cvCreateImage(cvSize(1000,1000), src->depth, src->nChannels);zoom(src, dst);cvShowImage("src", src);cvShowImage("dst", dst);cvWaitKey(0);return 1;
}
/****************************
*返回绝对值
*****************************/
float Abs(float f)
{return f>=0 ? f : -f;
}
/****************************
*目标： 实现图像的缩放，使用了双线性插值的算法*参数： src源图像dst生成图像*返回值：无
*****************************/
void zoom(IplImage* src, IplImage* dst)
{int srcWidth = src->width;int srcHeight = src->height;int dstWidth = dst->width;int dstHeight = dst->height;//源图像与目标图像的宽高比例,这里减1很重要，否则有时报错，有时不报错。这点困扰了我很久const float tx = (srcWidth-1.0f)/(dstWidth-1.0f);const float ty = (srcHeight-1.0f)/(dstHeight-1.0f);CvPoint2D32f uv;//存储源图像的浮点坐标CvPoint3D32f f1;CvPoint3D32f f2;for (int j=0; j<dstHeight-1; j++){for (int i=0; i<dstWidth-1; i++){uv.x = i*tx;uv.y = j*ty;int iu = (int)uv.x;int iv = (int)uv.y;f1.x = ((uchar*)(src->imageData + src->widthStep*iv))[iu*3+0] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*iv))[(iu+1)*3+0] * (uv.x-iu);f1.y = ((uchar*)(src->imageData + src->widthStep*iv))[iu*3+1] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*iv))[(iu+1)*3+1] * (uv.x-iu);f1.z = ((uchar*)(src->imageData + src->widthStep*iv))[iu*3+2] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*iv))[(iu+1)*3+2] * (uv.x-iu);f2.x = ((uchar*)(src->imageData + src->widthStep*(iv+1)))[iu*3] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*(iv+1)))[(iu+1)*3] * (uv.x-iu);f2.y = ((uchar*)(src->imageData + src->widthStep*(iv+1)))[iu*3+1] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*(iv+1)))[(iu+1)*3+1] * (uv.x-iu);f2.z = ((uchar*)(src->imageData + src->widthStep*(iv+1)))[iu*3+2] * (1-Abs(uv.x-iu))+((uchar*)(src->imageData + src->widthStep*(iv+1)))[(iu+1)*3+2] * (uv.x-iu);((uchar*)(dst->imageData + dst->widthStep*j))[i*3] = f1.x*(1-Abs(uv.y-iv))+f2.x*(Abs(uv.y-iv));((uchar*)(dst->imageData + dst->widthStep*j))[i*3+1] = f1.y*(1-Abs(uv.y-iv))+f2.y*(Abs(uv.y-iv));((uchar*)(dst->imageData + dst->widthStep*j))[i*3+2] = f1.z*(1-Abs(uv.y-iv))+f2.z*(Abs(uv.y-iv));}//这里添加上最后一列((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-1)*3] = ((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-2)*3];((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-1)*3+1] = ((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-2)*3+1];((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-1)*3+2] = ((uchar*)(dst->imageData + dst->widthStep*j))[(dstWidth-2)*3+2];}//这里添加上最后一行for(int i=0; i<dstWidth*3; i++){((uchar*)(dst->imageData + dst->widthStep*(dstHeight-1)))[i] = ((uchar*)(dst->imageData + dst->widthStep*(dstHeight-2)))[i];}
}

效果图：