使用openCv和Java进行图像处理的排名算法

Question

The below Algorithm returns image comparison percentage using openCv Java.

private double compare(Mat hist1, String f2) {
        double compare = 0;

        ArrayList<Mat> bgr_planes2 = new ArrayList<Mat>();
        boolean accumulate = false;
        MatOfInt histSize = new MatOfInt(180);
        MatOfInt channels = new MatOfInt(0);
        MatOfFloat histRanges = new MatOfFloat(0f, 180f);

        // Mat img2 = Imgcodecs.imread(f2);
        // img2 = resize(img2);

        Mat img2 = ContourUtils.findContour(f2, false);

        Imgproc.cvtColor(img2, img2, Imgproc.COLOR_RGBA2GRAY);
        img2.convertTo(img2, CvType.CV_32F);
        Mat hist2 = new Mat();
        Core.split(img2, bgr_planes2);
        Imgproc.calcHist(bgr_planes2, channels, new Mat(), hist2, histSize,
                histRanges, accumulate);
        Core.normalize(hist2, hist2, 0, hist2.rows(), Core.NORM_MINMAX, -1,
                new Mat());
        // img2.convertTo(img2, CvType.CV_32F);
        hist2.convertTo(hist2, CvType.CV_32F);

        compare = Imgproc.compareHist(hist1, hist2, Imgproc.CV_COMP_CORREL);
        img2.release();
        hist2.release();
        channels.release();
        histRanges.release();
        histSize.release();

        for (Mat m : bgr_planes2) {
            if (m != null) {
                m.release();
            }
        }

        return compare;
    }

Same way i want to find the ranking instead of percentage that how well the images are matched. Please suggest me an idea for ranking algorithm. Thanks.

Answer 1

I understand that your algorithm is comparing an image to a reference image. If you want a ranking of the best math, apply the function to your collection of input image, then sorting the results (descending order) provide you the ranking.

Store the result as key and the list of names of input image (expecting many inputs could have the same result value) as value of a Map. For example:

Map<double, List<String>> ranking