5

我一直在尝试将图像添加到所需位置的大图像。我找到了一种通过 addWeighted(src, alpha, water,--,dst,--) 在 opencv 中添加水印的方法，但问题是水印和表面图像的大小应该相同，这是我不想要的。

找到了另一种方式（我猜）

Mat srcMat = cvCanvasImage.submat(top/2, (top + height)/2, left/2, (left + width)/2);
Imgproc.cvtColor(mat, srcMat, Imgproc.COLOR_GRAY2BGR,4);

但我不明白如何做到这一点？

谢谢..

更新

     Mat cvCanvasImage = Highgui.imread(Environment.getExternalStorageDirectory() + "/wallpapers/castle.jpg");

 // Small watermark image
Mat cvWaterImage = Highgui.imread(Environment.getExternalStorageDirectory() +"/square.png");

Size canvasSize = cvWaterImage.size();

   int rows = (int) canvasSize.height;
   int cols = (int) canvasSize.width;       
   int left = 0;
   int top = 0;         
   int width = rows;
   int height = cols;

   Rect ROI = new Rect(left, top, width, height);
   Core.addWeighted(cvCanvasImage.submat(ROI), alpha, cvWaterImage, beta, 0, cvCanvasImage.submat(ROI)); 

  //now it throws me this error   

                             "error: (-209) The operation is neither 'array op array' (where arrays have the same size and the same number of channels), nor 'array op scalar', nor 'scalar op array' in function void cv::arithm_op(const cv::_InputArray&, const cv::_InputArray&, const cv::_OutputArray&, const cv::_InputArray&, int, void (**)(const uchar*, size_t, const uchar*, size_t, uchar*, size_t, cv::Size, void*), bool, void*)"
4

2 回答 2

6

我找到了一种正确的方法。

Mat b = Highgui.imread(Environment.getExternalStorageDirectory() + "/castle.jpg");

// Small watermark image
Mat a = Highgui.imread(Environment.getExternalStorageDirectory() +"/square.png");

Mat bSubmat = b.submat(a.rows(), a.rows()*2, a.cols(), a.cols()*2);        
a.copyTo(bSubmat);

Highgui.imwrite("mnt/sdcard/SubmatCopyToTest.png", b);
于 2012-10-23T04:45:11.187 回答
2

像这样的东西应该工作： 

Mat waterMark = new Mat(width, height); //assumed as a smaller image than your source mat, with size (width, height).

Rect ROI = new Rect(x, y, width, height); // Position and size of your watermark;

Core.addWeighted(source.submat(ROI), alpha, waterMark, beta, gamma, source.submat(ROI));
于 2012-10-04T09:07:26.260 回答