将合并的RGB图像转换为灰度OPENCV ANDROID

问题描述:

我试图将RGB图像(http://www.kavim.com/uploads/signs/tn__51A2376.JPG) 拆分为单独的通道,对每个通道进行阈值并将其合并回来,从而导致类似的情况。将合并的RGB图像转换为灰度OPENCV ANDROID

enter image description here

我不明白的是,为什么,如果我尝试合并后的图像转换为灰度我得到这个颜色阈值输出(而不是灰度图像代替)。

public Mat onCameraFrame(CvCameraViewFrame inputFrame) { 
     Mat rgba = inputFrame.rgba(); 
     Size sizeRgba = rgba.size(); 
     Mat grayInnerWindow1; 
     Mat rgbaInnerWindow; 

     int rows = (int) sizeRgba.height; 
     int cols = (int) sizeRgba.width; 

     int left = cols/8; 
     int top = rows/8; 

     int width = cols * 3/4; 
     int height = rows * 3/4; 

      rgbaInnerWindow = rgba.submat(top, top + height, left, left + width); 

     ArrayList<Mat> channels = new ArrayList<Mat>(3); 

     Mat src1= Mat.zeros(rgbaInnerWindow.size(),CvType.CV_8UC3); 

     Core.split(rgbaInnerWindow, channels); 

     Mat b = channels.get(0); 
     Imgproc.threshold(b, b, 0, 70, Imgproc.THRESH_BINARY | Imgproc.THRESH_OTSU); 
     Mat g = channels.get(1); 
     Imgproc.threshold(g, g, 0, 70, Imgproc.THRESH_BINARY | Imgproc.THRESH_OTSU); 
     Mat r = channels.get(2); 
     Imgproc.threshold(r, r, 90, 255, Imgproc.THRESH_BINARY | Imgproc.THRESH_OTSU); 

     Core.merge(channels, src1); 
     Imgproc.medianBlur(src1, src1, 3); 

     Imgproc.threshold(src1,rgbaInnerWindow,0, 255, Imgproc.THRESH_BINARY); 
     Imgproc.cvtColor(rgbaInnerWindow,src1, Imgproc.COLOR_BGR2GRAY); 

       rgbaInnerWindow.release(); 

      return rgba; 
     } 
    } 

问题是,我试图将设置为inputFrame.rgba()的对象设置为灰色。

为此,我必须创建另一个mat set作为inputFrame.gray(),然后尝试将其转换。

Mat rgb = inputFrame.rgba(); 
Mat gray = inputFrame.gray(); 
Mat grayInnerWindow = gray.submat(top, top + height, left, left + width); 
Mat rgbaInnerWindow = rgba.submat(top, top + height, left, left + width); 
//SOME CODE 
Imgproc.cvtColor(rgbaInnerWindow,grayInnerWindow, Imgproc.COLOR_BGR2GRAY); 

现在这样工作,因为它应该!