为什么cvPutText在这种情况下不起作用?

时间:2012-03-11 12:34:57

标签: c++ opencv

我正在使用openCV函数cvPutText,但似乎它不会执行或很快被覆盖。这是我的代码块:

          ...
if(showResult==1){

        cvNamedWindow("Znak", CV_WINDOW_AUTOSIZE);
        cvShowImage("Znak", znak);

        if(result == 0){
            ascii_result = "A";
            cvSet(znak, cvScalar(26,26,26));
            cvPutText(znak, "A", cvPoint(13, 185), &font, cvScalar(255, 166, 44, 0));
            printf("A working");
        }
        if(result == 1){
            ascii_result = "B";
            cvSet(znak, cvScalar(26,26,26));
            cvPutText(znak, "B", cvPoint(13, 185), &font, cvScalar(255, 166, 44, 0));
            printf("B working");
        }
          ...

它不在任何循环中。问题是,创建了“Znak”窗口,但 cvSet() cvPutText 将不会执行或被覆盖...所以我只看到空白窗口它黯淡的灰色

1 个答案:

答案 0 :(得分:2)

每次对图像进行更改并希望显示时,都应放置CvShowImage。

      ...
    if(showResult==1){

    cvNamedWindow("Znak", CV_WINDOW_AUTOSIZE);
    cvShowImage("Znak", znak);

    if(result == 0){
        ascii_result = "A";
        cvSet(znak, cvScalar(26,26,26));
        cvPutText(znak, "A", cvPoint(13, 185), &font, cvScalar(255, 166, 44, 0));
        cvShowImage("Znak", znak);
        printf("A working");
    }
    if(result == 1){
        ascii_result = "B";
        cvSet(znak, cvScalar(26,26,26));
        cvPutText(znak, "B", cvPoint(13, 185), &font, cvScalar(255, 166, 44, 0));
        cvShowImage("Znak", znak);
        printf("B working");
    }
      ...

当您调用cvShowImage时,它会将图像的副本发送到窗口。如果您更改代码中的图像,它将不会在窗口中更改,因为它只是旧图像的副本。