Question

我正在尝试打印从图像文件中输入的矩阵的值，该文件的类型为CV_8UC4。我的代码写在下面。我的问题是我得到的值只有48和255，而我期待的值是2和1或者其他什么。有人知道为什么吗？我想我是以错误的方式打印价值观。有没有其他方法来打印CV_8UC4的值。我的代码是：

CvMat* m1 = cvLoadImageM(argv[1], CV_LOAD_IMAGE_UNCHANGED); // load the matrix from an image file
cv::Mat m1cpp(m1);
int type = m1cpp.type();
printf( " type is %d  ", type );

switch( type ) {

 case 24:
   printf("\n --> Matrix type is CV_8U \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %d  ", m1cpp.at<uchar>(i,j) );
     } printf("\n");
   }
 break;


 case 25:
   printf("\n --> Matrix type is CV_8S \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %d  ", m1cpp.at<schar>(i,j) );
     } printf("\n");
   }
 break;


 case 18:
   printf("\n --> Matrix type is CV_16U \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %d  ", m1cpp.at<ushort>(i,j) );
     } printf("\n");
   }
 break;


 case 27:
   printf("\n --> Matrix type is CV_16S \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %d  ", m1cpp.at<short>(i,j) );
     } printf("\n");
   }
 break;


 case 28:
   printf("\n --> Matrix type is CV_32S \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %d  ", m1cpp.at<int>(i,j) );
     } printf("\n");
   }
 break;

 case 29:
   printf("\n --> Matrix type is CV_32F \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %.3f  ", m1cpp.at<float>(i,j) );
     } printf("\n");
   }
 break;


 case 30:
   printf("\n --> Matrix type is CV_64F \n");

   for( size_t i = 0; i < m1cpp.rows; i++ ) {
     for( size_t j = 0; j < m1cpp.cols; j++ ) {
       printf( " %.3f  ", m1cpp.at<double>(i,j) );
     } printf("\n");
   }
  break;

   default:
printf("\n --> Matrix type not found \n");

 }

我的情况是24，我的有线值为48和255.还有其他方法可以打印CV_8UC4值吗？

Answer 1

正确访问您的CV_8UC4矩阵：

    image.at<cv::Vec4b>(j,i)[0];
    image.at<cv::Vec4b>(j,i)[1];
    image.at<cv::Vec4b>(j,i)[2];
    image.at<cv::Vec4b>(j,i)[3];

在OpenCV中打印CV_8UC4矩阵类型的值

1 个答案: