OpenCV编程注意事项

1. 截取其中一部分的操作可以为：

CvRect roi = cvRect(x1, y1, width1, height1);inputImage = cvLoadImage(filename);cvSetImageROI(inputImage, roi);IplImage* temp = cvCreateImage(cvSize(width1, height1), inputImage->depth, inputImage->nChannels);cvCopy(inputImage, temp);

2. 注意cvResetImageROI,cvReleaseImage

3. 遍历图像：千万千万注意先height再width！

        for(int i = 0 ; i < height; i++){uchar* ptr = (uchar*)(inputImage->imageData + i * inputImage->widthStep);for(int j = 0 ; j < width; j++){int value = ptr[3*j];sumgreen += value;}}

4. 转灰度图

IplImage* gray = cvCreateImage(cvGetSize(inputImage),inputImage->depth,1);cvCvtColor(inputImage, gray, CV_BGR2GRAY);