in.fabinpaul.sixthsense.ColorBlobDetector.java Source code

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Here is the source code for in.fabinpaul.sixthsense.ColorBlobDetector.java

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/*
 * Copyright (C) 2013 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package in.fabinpaul.sixthsense;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ColorBlobDetector {
    // Lower and Upper bounds for range checking in HSV color space
    private Scalar mLowerBound = new Scalar(0);
    private Scalar mUpperBound = new Scalar(0);
    // Minimum contour area in percent for contours filtering
    private static double mMinContourArea = 0.1;
    // Color radius for range checking in HSV color space
    private Scalar mColorRadius = new Scalar(5, 30, 50, 0);
    private Mat mSpectrum = new Mat();
    private List<MatOfPoint> mContours = new ArrayList<MatOfPoint>();
    Point marker;

    // Cache
    Mat mPyrDownMat = new Mat();
    Mat mHsvMat = new Mat();
    Mat mMask = new Mat();
    Mat mDilatedMask = new Mat();
    Mat mHierarchy = new Mat();

    public void setColorRadius(Scalar radius) {
        mColorRadius = radius;
    }

    public void setHsvColor(Scalar hsvColor) {
        double minH = (hsvColor.val[0] >= mColorRadius.val[0]) ? hsvColor.val[0] - mColorRadius.val[0] : 0;
        double maxH = (hsvColor.val[0] + mColorRadius.val[0] <= 255) ? hsvColor.val[0] + mColorRadius.val[0] : 255;

        mLowerBound.val[0] = minH;
        mUpperBound.val[0] = maxH;

        mLowerBound.val[1] = hsvColor.val[1] - mColorRadius.val[1];
        mUpperBound.val[1] = hsvColor.val[1] + mColorRadius.val[1];

        mLowerBound.val[2] = hsvColor.val[2] - mColorRadius.val[2];
        mUpperBound.val[2] = hsvColor.val[2] + mColorRadius.val[2];

        mLowerBound.val[3] = 0;
        mUpperBound.val[3] = 255;

        Mat spectrumHsv = new Mat(1, (int) (maxH - minH), CvType.CV_8UC3);

        for (int j = 0; j < maxH - minH; j++) {
            byte[] tmp = { (byte) (minH + j), (byte) 255, (byte) 255 };
            spectrumHsv.put(0, j, tmp);
        }

        Imgproc.cvtColor(spectrumHsv, mSpectrum, Imgproc.COLOR_HSV2RGB_FULL, 4);
    }

    public Mat getSpectrum() {
        return mSpectrum;
    }

    public void setMinContourArea(double area) {
        mMinContourArea = area;
    }

    public void process(Mat rgbaImage) {
        Imgproc.pyrDown(rgbaImage, mPyrDownMat);
        Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

        Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

        Core.inRange(mHsvMat, mLowerBound, mUpperBound, mMask);
        Imgproc.dilate(mMask, mDilatedMask, new Mat());

        List<MatOfPoint> contours = new ArrayList<MatOfPoint>();

        Imgproc.findContours(mDilatedMask, contours, mHierarchy, Imgproc.RETR_EXTERNAL,
                Imgproc.CHAIN_APPROX_SIMPLE);

        // Find max contour area
        double maxArea = 0;
        Iterator<MatOfPoint> each = contours.iterator();
        while (each.hasNext()) {
            MatOfPoint wrapper = each.next();
            double area = Imgproc.contourArea(wrapper);
            if (area > maxArea)
                maxArea = area;
        }

        // Filter contours by area and resize to fit the original image size
        mContours.clear();
        each = contours.iterator();
        while (each.hasNext()) {
            MatOfPoint contour = each.next();
            if (Imgproc.contourArea(contour) > mMinContourArea * maxArea) {
                Core.multiply(contour, new Scalar(4, 4), contour);
                mContours.add(contour);
            }
        }
    }

    public List<MatOfPoint> getContours() {
        return mContours;
    }

    public Point getXY() {
        marker = new Point();
        for (int i = 0; i < mMask.rows(); i++) {
            for (int j = 0; j < mMask.cols(); j++) {

            }
        }
        return marker;
    }
}