opencv 数字图像处理-图像错切

来源：互联网发布：淘宝网差评的危害编辑：程序博客网时间：2024/06/05 15:23

图像的错切变换实际上是平面景物在投影平面上的非垂直投影效果。图像错切变换也称为图像剪切、错位或错移变换。图像错切的原理就是保持图像上各点的某一坐标不变，将另一个坐标进行线性变换，坐标不变的轴称为依赖轴，坐标变换的轴称为方向轴。图像错切一般分为两种情况：水平方向错切和垂直方向错切。

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水平方向的错切，即沿x轴方向关于y的错切，即x=x0+c*y0, y=y0

若c>0，则沿+x轴方向错切，反之，如果c<0，则沿-x轴方向错切.

void imageTwist(IplImage *src, IplImage *res, float ratio){cvZero(res);int res_wid;int res_hei;unsigned char* src_data = (unsigned char*)src->imageData;unsigned char* res_data = (unsigned char*)res->imageData;for (int i=0; i<src->height; i++){if (ratio >= 0)for (int j=0; j<src->width; j++){res_hei=i;res_wid=j+res_hei*ratio;res_data[res_hei*res->widthStep+res_wid] = src_data[i*src->widthStep+j];}else {int offset=ratio*src->height;for (int j=src->width-1; j>=0; j--){res_hei=i;res_wid=j+res_hei*ratio;res_data[res_hei*res->widthStep+res_wid+offset] = src_data[i*src->widthStep+j];}}}cvNamedWindow("src");cvNamedWindow("res");cvShowImage("src", src);cvShowImage("res", res);cvWaitKey(0);cvReleaseImage(&src);cvReleaseImage(&res);cvDestroyAllWindows();}void imageCutting(void){src=cvLoadImage("lena.jpg", 0);if (src == NULL)exit(0);float ratio;cout<<"输入水平错切比率："<<endl;cin>>ratio;int res_wid;int res_hei;if (ratio < 0){res_wid=src->width+src->height*ratio*(-1);} else {res_wid=src->width+src->height*ratio;}res_hei=src->height;CvSize size=cvSize(res_wid, res_hei);res=cvCreateImage(size, src->depth, src->nChannels);if (res == NULL)exit(0);imageTwist(src, res, ratio);//图像扭曲}

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垂直方向错切，即沿y轴方向关于x的错切。与水平错切类似变换，即x=x0, y=y0+b*x0

void imageTwistV(IplImage *src, IplImage *res, float ratio){cvZero(res);int res_wid;int res_hei;unsigned char* src_data = (unsigned char*)src->imageData;unsigned char* res_data = (unsigned char*)res->imageData;for (int i=0; i<src->width; i++){if (ratio >= 0){int offset=ratio*src->width;for (int j=0; j<src->height; j++){res_wid=i;res_hei=j+offset-res_wid*ratio;res_data[res_hei*res->widthStep+res_wid] = src_data[j*src->widthStep+i];}}else {//int offset=ratio*src->height*(-1);for (int j=src->height-1; j>=0; j--){res_wid=i;res_hei=j+res_wid*ratio*(-1);res_data[res_hei*res->widthStep+res_wid] = src_data[j*src->widthStep+i];}}}cvNamedWindow("src");cvNamedWindow("res");cvShowImage("src", src);cvShowImage("res", res);cvWaitKey(0);cvReleaseImage(&src);cvReleaseImage(&res);cvDestroyAllWindows();}void imageCutting(void){src=cvLoadImage("lena.jpg", 0);if (src == NULL)exit(0);float ratio=0;cout<<"输入垂直错切比率："<<endl;cin>>ratio;int res_wid;int res_hei;if (ratio < 0){res_hei=src->height+src->width*ratio*(-1);//res_wid=src->width+src->height*ratio*(-1);} else {res_hei=src->height+src->width*ratio;//res_wid=src->width+src->height*ratio;}res_wid=src->width;//res_hei=src->height;CvSize size=cvSize(res_wid, res_hei);res=cvCreateImage(size, src->depth, src->nChannels);if (res == NULL)exit(0);//imageTwistH(src, res, ratio);//图像扭曲imageTwistV(src, res, ratio);}

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