Example usage for org.opencv.core Core minMaxLoc

Introduction

In this page you can find the example usage for org.opencv.core Core minMaxLoc.

Prototype

public static MinMaxLocResult minMaxLoc(Mat src, Mat mask) 

Source Link

Usage

From source file:org.ar.rubik.MonoChromatic.java

License:Open Source License

/**
 * Use OpenCV minMax.//w  w  w  . j a  v  a  2s. c o  m
 * 
 * However, this is enormously slow, taking 10 minutes per frame!  Why?
 * I think because it is effective O(O^4) in computation.
 * 
 * @param original_image
 * @return
 */
@SuppressWarnings("unused")
private static Mat monochromaticMedianImageFilterUtilizingOpenCv(Mat original_image) {

    final Size imageSize = original_image.size();
    final int numColumns = (int) original_image.size().width;
    final int numRows = (int) original_image.size().height;
    final int bufferSize = numColumns * numRows;
    final int span = (int) 7;
    final int accuracy = (int) 5;

    Mat hsv_image = new Mat(imageSize, CvType.CV_8UC3);
    Imgproc.cvtColor(original_image, hsv_image, Imgproc.COLOR_RGB2HLS);
    List<Mat> channels = new LinkedList<Mat>();
    Core.split(hsv_image, channels);
    Mat hueMat = channels.get(0);
    Mat lumMat = channels.get(1);
    Mat satMat = channels.get(2);

    // Output byte array for speed efficiency
    Mat monochromatic_image = new Mat(imageSize, CvType.CV_8UC1);
    byte[] monochromaticByteArray = new byte[bufferSize];

    Mat mask = Mat.zeros(numRows, numColumns, CvType.CV_8UC1);

    Log.i(Constants.TAG, "Begin MonoChromatic CV");
    for (int row = 0; row < numRows; row++) {

        byte result_pixel = 0;

        for (int col = 0; col < numColumns; col++) {

            if (col < span || (col >= numColumns - span))
                result_pixel = 0; // Just put in black

            else if (row < span || (row >= numRows - span))
                result_pixel = 0; // Just put in black

            else {

                //               Log.i(Constants.TAG, "Creating Mask at " + row +"," + col);
                Core.rectangle(mask, new Point(row, col), new Point(row + span, col + span),
                        new Scalar(1, 1, 1));

                Core.MinMaxLocResult minMaxResult = Core.minMaxLoc(hueMat, mask);

                if (((minMaxResult.maxVal - minMaxResult.maxVal) < accuracy)) //&& (lum_max - lum_min < accuracy) && (sat_max - sat_min < accuracy) )
                    result_pixel = (byte) 128;
                else
                    result_pixel = (byte) 0;
                //               Log.i(Constants.TAG, "Completed Mask at " + row +"," + col);

                Core.rectangle(mask, new Point(row, col), new Point(row + span, col + span),
                        new Scalar(0, 0, 0));
            }

            if ((col >= span / 2) && (row >= span / 2))
                monochromaticByteArray[(row - span / 2) * numColumns + (col - span / 2)] = result_pixel;
        }

        Log.i(Constants.TAG, "Completed Row: " + row);

    }

    monochromatic_image.put(0, 0, monochromaticByteArray);
    Log.i(Constants.TAG, "Completed MonoChromatic CV");
    //      System.exit(0);
    return monochromatic_image;
}

---