Question

我需要一些代码帮助。我想写一些类似于： LINK

我从前置手机摄像头拍了两张小的.png照片。我对calc直方图有疑问。有代码：

        Mat img=new Mat();
        img=org.opencv.highgui.Highgui.imread(imgLocation);
        List<Mat> imagesList=new ArrayList<Mat>();
        imagesList.add(img);
        int channelArray[]={0,1,2};
        MatOfInt channels=new MatOfInt(channelArray);
        Mat hist=new Mat();
        MatOfInt histSize=new MatOfInt(256);
        MatOfFloat ranges=new MatOfFloat(0.0f,255.0f);
        org.opencv.imgproc.Imgproc.calcHist(imagesList, channels,new Mat(), hist, histSize, ranges);
        return hist;

我收到了一个错误：

12-10 02:37:53.157: E/cv::error()(6203): OpenCV Error: Assertion failed (csz == 0 || csz == dims) in void cv::calcHist(cv::InputArrayOfArrays, const std::vector<int>&, cv::InputArray, cv::OutputArray, const std::vector<int>&, const std::vector<float>&, bool), file /home/reports/ci/slave_desktop/50-SDK/opencv/modules/imgproc/src/histogram.cpp, line 1427

Answer 1

我是用那段代码制作的：

    public void compare()
{
    String filenameLeft = null, filenameCurrent = null, filenameLeftHist = null, filenameCurrentHist = null;
    File fileLeft = null, fileCurrent = null, fileLeftHist = null, fileCurrentHist = null;
    File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES); // sciezka do sdcard
    fileLeft = new File(path, "left.png");fileCurrent = new File(path, "current.png"); fileLeftHist = new File(path, "leftHist.png"); fileCurrentHist  = new File(path, "currentHist.png");
    filenameLeft = fileLeft.toString(); filenameCurrent = fileCurrent.toString(); filenameLeftHist = fileLeftHist.toString(); filenameCurrentHist = fileCurrentHist.toString();

    Mat H1 = histogram(filenameLeft,filenameLeftHist);
    Mat H2 = histogram(filenameCurrent,filenameCurrentHist);
    double text = Imgproc.compareHist(H1, H2, Imgproc.CV_COMP_BHATTACHARYYA);
    if(text<0.2)Log.d(TAG,"Skrecam W LEWO, bo: "+text);
    else Log.d(TAG, "Nie skrecam w LEWO, bo: "+text);
}
public Mat histogram(String filenameIn,String filenameOut) // zwraca histogram obrazu
{
    Mat img = Highgui.imread(filenameIn);
    Mat src = new Mat(img.height(), img.width(), CvType.CV_8UC2);
    Imgproc.cvtColor(img, src, Imgproc.COLOR_RGB2GRAY);
    Vector<Mat> bgr_planes = new Vector<Mat>();                                                                                                                                                                                 
    Core.split(src, bgr_planes);
    MatOfInt histSize = new MatOfInt(256);
    final MatOfFloat histRange = new MatOfFloat(0f, 256f);
    boolean accumulate = false;
    Mat b_hist = new  Mat();
    Imgproc.calcHist(bgr_planes, new MatOfInt(0),new Mat(), b_hist, histSize, histRange, accumulate);
    Highgui.imwrite(filenameOut, b_hist);
    return b_hist;
}

我在onCameraFrame（）方法中使用compare（）。它运作良好，但我有疑问。

有什么选择可以让它更准确吗？它很大程度上依赖于光线，有时相同的布局口不能很好地工作。我在这里比较2个直方图。

Answer 2

您需要为每个频道指定histsize。

所以而不是

MatOfInt histSize=new MatOfInt(256);

尝试

MatOfInt histSize=new MatOfInt(256,256,256);

范围也是如此。指定每个通道的下限和上限。

直方图比较

2 个答案: