c - Opencv cvSetImageROI坐标问题

Question

在我的应用程序中，我使用 opencv 裁剪具有特定坐标的图像，但问题是当我移动左侧的坐标时，它是向上的一侧进行更改，所以我不明白。

//assignment of calculates ration between view resolution and resolution of the photograph
double scaleX = (outPutImage.frame.size.width/newCoordRect.imgWidth);
double scaleY = (outPutImage.frame.size.height/newCoordRect.imgHeight);

//assignment of the values after calculates coordinates
int x = newCoordRect.leftUp.x/(scaleX);
int y = newCoordRect.leftUp.y/(scaleY);

int heigth = ((newCoordRect.rightDown.y-newCoordRect.rightUp.y)/scaleY);
int width = ((newCoordRect.rightDown.x-newCoordRect.leftUp.x)/scaleX);

/* load image */
IplImage *img1 = [[ShareFunction sFunction]CreateIplImageFromUIImage:outPutImage.image];

/* sets the Region of Interest
 Note that the rectangle area has to be __INSIDE__ the image */
cvSetImageROI(img1, cvRect(x, y, width, heigth));

/* create destination image
 Note that cvGetSize will return the width and the height of ROI */
IplImage *img2 = cvCreateImage(cvGetSize(img1),
                               img1->depth,
                               3);

/* copy subimage */
cvCopy(img1, img2, NULL);

/* always reset the Region of Interest */
cvResetImageROI(img1);

retCropImg = [[ShareFunction sFunction]UIImageFromIplImage:img2];

有什么想法吗？

Answer 1

你的代码似乎是正确的。看一下图像的方向