Java Code Examples for org.opencv.core.Core#multiply()

public void DifferenceOfGaussian() {
    Mat grayMat = new Mat();
    Mat blur1 = new Mat();
    Mat blur2 = new Mat();

    //Converting the image to grayscale
    Imgproc.cvtColor(originalMat, grayMat, Imgproc.COLOR_BGR2GRAY);

    Imgproc.GaussianBlur(grayMat, blur1, new Size(15, 15), 5);
    Imgproc.GaussianBlur(grayMat, blur2, new Size(21, 21), 5);

    //Subtracting the two blurred images
    Mat DoG = new Mat();
    Core.absdiff(blur1, blur2, DoG);

    //Inverse Binary Thresholding
    Core.multiply(DoG, new Scalar(100), DoG);
    Imgproc.threshold(DoG, DoG, 50, 255, Imgproc.THRESH_BINARY_INV);

    //Converting Mat back to Bitmap
    Utils.matToBitmap(DoG, currentBitmap);
    imageView.setImageBitmap(currentBitmap);
}
 

public static Mat transEstimate(Mat img, int patchSz, double[] airlight, double lambda, double fTrans, 
		int r, double eps, double gamma) {
	int rows = img.rows();
	int cols = img.cols();
	List<Mat> bgr = new ArrayList<>();
	Core.split(img, bgr);
	int type = bgr.get(0).type();
	// calculate the transmission map
	Mat T = computeTrans(img, patchSz, rows, cols, type, airlight, lambda, fTrans);
	// refine the transmission map
	img.convertTo(img, CvType.CV_8UC1);
	Mat gray = new Mat();
	Imgproc.cvtColor(img, gray, Imgproc.COLOR_BGR2GRAY);
	gray.convertTo(gray, CvType.CV_32F);
	Core.divide(gray, new Scalar(255.0), gray);
	T = Filters.GuidedImageFilter(gray, T, r, eps);
	Mat Tsmooth = new Mat();
	Imgproc.GaussianBlur(T, Tsmooth, new Size(81, 81), 40);
	Mat Tdetails = new Mat();
	Core.subtract(T, Tsmooth, Tdetails);
	Core.multiply(Tdetails, new Scalar(gamma), Tdetails);
	Core.add(Tsmooth, Tdetails, T);
	return T;
}
 

private static List<Mat> globalAdaptation(Mat b, Mat g, Mat r, int rows, int cols) {
	// Calculate Lw & maximum of Lw
	Mat Lw = new Mat(rows, cols, r.type());
	Core.multiply(r, new Scalar(rParam), r);
	Core.multiply(g, new Scalar(gParam), g);
	Core.multiply(b, new Scalar(bParam), b);
	Core.add(r, g, Lw);
	Core.add(Lw, b, Lw);
	double LwMax = Core.minMaxLoc(Lw).maxVal; // the maximum luminance value
	// Calculate log-average luminance and get global adaptation result
	Mat Lw_ = Lw.clone();
	Core.add(Lw_, new Scalar(0.001), Lw_);
	Core.log(Lw_, Lw_);
	double LwAver = Math.exp(Core.sumElems(Lw_).val[0] / (rows * cols));
	Mat Lg = Lw.clone();
	Core.divide(Lg, new Scalar(LwAver), Lg);
	Core.add(Lg, new Scalar(1.0), Lg);
	Core.log(Lg, Lg);
	Core.divide(Lg, new Scalar(Math.log(LwMax / LwAver + 1.0)), Lg); // Lg is the global adaptation
	List<Mat> list = new ArrayList<>();
	list.add(Lw);
	list.add(Lg);
	return list;
}
 

private static double getImageBrightness(Mat img){
    Mat temp = new Mat();
    List<Mat> color = new ArrayList<Mat>(3);
    Mat lum = new Mat();
    temp = img;

    Core.split(temp, color);

    if(color.size() > 0){
        Core.multiply(color.get(0), new Scalar(0.299), color.get(0));
        Core.multiply(color.get(1), new Scalar(0.587), color.get(1));
        Core.multiply(color.get(2), new Scalar(0.114), color.get(2));

        Core.add(color.get(0),color.get(1),lum);
        Core.add(lum, color.get(2), lum);

        Scalar sum = Core.sumElems(lum);

        return sum.val[0]/((1<<8 - 1)*img.rows() * img.cols()) * 2;
    } else {
        return 1;
    }
}
 

private static double getImageBrightness(Mat img){
    Mat temp = new Mat();
    List<Mat> color = new ArrayList<Mat>(3);
    Mat lum = new Mat();
    temp = img;

    Core.split(temp, color);

    if(color.size() > 0){
        Core.multiply(color.get(0), new Scalar(0.299), color.get(0));
        Core.multiply(color.get(1), new Scalar(0.587), color.get(1));
        Core.multiply(color.get(2), new Scalar(0.114), color.get(2));

        Core.add(color.get(0),color.get(1),lum);
        Core.add(lum, color.get(2), lum);

        Scalar sum = Core.sumElems(lum);

        return sum.val[0]/((1<<8 - 1)*img.rows() * img.cols()) * 2;
    } else {
        return 1;
    }
}
 

private static Mat preDehaze(Mat img, double a, double nTrans) {
	// nOut = ( (blkIm - a) * nTrans + 128 * a ) / 128;
	Core.subtract(img, new Scalar(a), img);
	Core.multiply(img, new Scalar(nTrans), img);
	Core.add(img, new Scalar(128.0 * a), img);
	Core.divide(img, new Scalar(128.0), img);
	return img;
}
 

@SuppressWarnings("unused")
public static Mat enhanceEachChannel(Mat image, int blkSize, int patchSize, double lambda, double eps, int krnlSize) {
	image.convertTo(image, CvType.CV_32F);
	// split image to three channels
	List<Mat> bgr = new ArrayList<>();
	Core.split(image, bgr);
	Mat bChannel = bgr.get(0);
	Mat gChannel = bgr.get(1);
	Mat rChannel = bgr.get(2);
	// obtain air-light
	double[] airlight = AirlightEstimate.estimate(image, blkSize);
	// obtain coarse transmission map and refine it for each channel
	double fTrans = 0.3;
	Mat T = TransmissionEstimate.transEstimateEachChannel(bChannel, patchSize, airlight[0], lambda, fTrans);
	Core.subtract(T, new Scalar(1.0), T);
	Core.multiply(T, new Scalar(-1.0), T);
	Mat Tb = Filters.GuidedImageFilter(bChannel, T, krnlSize, eps);
	T = TransmissionEstimate.transEstimateEachChannel(gChannel, patchSize, airlight[1], lambda, fTrans);
	Core.subtract(T, new Scalar(1.0), T);
	Core.multiply(T, new Scalar(-1.0), T);
	Mat Tg = Filters.GuidedImageFilter(gChannel, T, krnlSize, eps);
	T = TransmissionEstimate.transEstimateEachChannel(rChannel, patchSize, airlight[2], lambda, fTrans);
	Core.subtract(T, new Scalar(1.0), T);
	Core.multiply(T, new Scalar(-1.0), T);
	Mat Tr = Filters.GuidedImageFilter(rChannel, T, krnlSize, eps);
	// dehaze
	bChannel = dehaze(bChannel, Tb, airlight[0]);
	gChannel = dehaze(gChannel, Tg, airlight[1]);
	rChannel = dehaze(rChannel, Tr, airlight[2]);
	Mat outval = new Mat();
	Core.merge(new ArrayList<>(Arrays.asList(bChannel, gChannel, rChannel)), outval);
	return outval;
}
 

private static Mat dehaze(Mat channel, Mat t, double minAtmosLight) {
	Mat t_ = new Mat();
	Core.subtract(t, new Scalar(1.0), t_);
	Core.multiply(t_, new Scalar(-1.0 * minAtmosLight), t_);
	Core.subtract(channel, t_, channel);
	Core.divide(channel, t, channel);
	return channel;
}
 

private static Mat pyramidFuse(Mat w1, Mat w2, Mat img1, Mat img2, int level) {
	// Normalized weight
	Mat sumW = new Mat();
	Core.add(w1, w2, sumW);
	Core.divide(w1, sumW, w1);
	Core.multiply(w1, new Scalar(2.0), w1);
	Core.divide(w2, sumW, w2);
	Core.multiply(w2, new Scalar(2.0), w2);
	// Pyramid decomposition and reconstruct
	return ImgDecompose.fuseTwoImage(w1, img1, w2, img2, level);
}
 

private static Mat dehazeProcess(Mat img, Mat trans, double[] airlight) {
	Mat balancedImg = Filters.SimplestColorBalance(img, 5);
	Mat bCnl = new Mat();
	Core.extractChannel(balancedImg, bCnl, 0);
	Mat gCnl = new Mat();
	Core.extractChannel(balancedImg, gCnl, 1);
	Mat rCnl = new Mat();
	Core.extractChannel(balancedImg, rCnl, 2);
	// get mean value
	double bMean = Core.mean(bCnl).val[0];
	double gMean = Core.mean(gCnl).val[0];
	double rMean = Core.mean(rCnl).val[0];
	// get transmission map for each channel
	Mat Tb = trans.clone();
	Core.multiply(Tb, new Scalar(Math.max(bMean, Math.max(gMean, rMean)) / bMean * 0.8), Tb);
	Mat Tg = trans.clone();
	Core.multiply(Tg, new Scalar(Math.max(bMean, Math.max(gMean, rMean)) / gMean * 0.9), Tg);
	Mat Tr = trans.clone();
	Core.multiply(Tr, new Scalar(Math.max(bMean, Math.max(gMean, rMean)) / rMean * 0.8), Tr);
	// dehaze by formula
	// blue channel
	Mat bChannel = new Mat();
	Core.subtract(bCnl, new Scalar(airlight[0]), bChannel);
	Core.divide(bChannel, Tb, bChannel);
	Core.add(bChannel, new Scalar(airlight[0]), bChannel);
	// green channel
	Mat gChannel = new Mat();
	Core.subtract(gCnl, new Scalar(airlight[1]), gChannel);
	Core.divide(gChannel, Tg, gChannel);
	Core.add(gChannel, new Scalar(airlight[1]), gChannel);
	// red channel
	Mat rChannel = new Mat();
	Core.subtract(rCnl, new Scalar(airlight[2]), rChannel);
	Core.divide(rChannel, Tr, rChannel);
	Core.add(rChannel, new Scalar(airlight[2]), rChannel);
	Mat dehazed = new Mat();
	Core.merge(new ArrayList<>(Arrays.asList(bChannel, gChannel, rChannel)), dehazed);
	return dehazed;
}
 

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 PreProcessor preprocessImage(PreProcessor preProcessor) {
    List<Mat> images = preProcessor.getImages();
    List<Mat> processed = new ArrayList<Mat>();
    for (Mat img : images){
        img.convertTo(img, CvType.CV_32F);
        Core.divide(img, INT_MAX, img);
        Core.pow(img, gamma, img);
        Core.multiply(img, INT_MAX, img);
        img.convertTo(img, CvType.CV_8U);
        processed.add(img);
    }
    preProcessor.setImages(processed);
    return preProcessor;
}
 

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 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 static Mat enhance(Mat image, double krnlRatio, double minAtmosLight, double eps) {
	image.convertTo(image, CvType.CV_32F);
	// extract each color channel
	List<Mat> rgb = new ArrayList<>();
	Core.split(image, rgb);
	Mat rChannel = rgb.get(0);
	Mat gChannel = rgb.get(1);
	Mat bChannel = rgb.get(2);
	int rows = rChannel.rows();
	int cols = rChannel.cols();
	// derive the dark channel from original image
	Mat dc = rChannel.clone();
	for (int i = 0; i < image.rows(); i++) {
		for (int j = 0; j < image.cols(); j++) {
			double min = Math.min(rChannel.get(i, j)[0], Math.min(gChannel.get(i, j)[0], bChannel.get(i, j)[0]));
			dc.put(i, j, min);
		}
	}
	// minimum filter
	int krnlSz = Double.valueOf(Math.max(Math.max(rows * krnlRatio, cols * krnlRatio), 3.0)).intValue();
	Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(krnlSz, krnlSz), new Point(-1, -1));
	Imgproc.erode(dc, dc, kernel);
	// get coarse transmission map
	Mat t = dc.clone();
	Core.subtract(t, new Scalar(255.0), t);
	Core.multiply(t, new Scalar(-1.0), t);
	Core.divide(t, new Scalar(255.0), t);
	// obtain gray scale image
	Mat gray = new Mat();
	Imgproc.cvtColor(image, gray, Imgproc.COLOR_RGB2GRAY);
	Core.divide(gray, new Scalar(255.0), gray);
	// refine transmission map
	int r = krnlSz * 4;
	t = Filters.GuidedImageFilter(gray, t, r, eps);
	// get minimum atmospheric light
	minAtmosLight = Math.min(minAtmosLight, Core.minMaxLoc(dc).maxVal);
	// dehaze each color channel
	rChannel = dehaze(rChannel, t, minAtmosLight);
	gChannel = dehaze(gChannel, t, minAtmosLight);
	bChannel = dehaze(bChannel, t, minAtmosLight);
	// merge three color channels to a image
	Mat outval = new Mat();
	Core.merge(new ArrayList<>(Arrays.asList(rChannel, gChannel, bChannel)), outval);
	outval.convertTo(outval, CvType.CV_8UC1);
	return outval;
}
 

/**
 * Process an rgba image. The results can be drawn on retrieved later.
 * This method does not modify the image.
 *
 * @param rgbaImage An RGBA image matrix
 */
public void process(Mat rgbaImage) {
    Imgproc.pyrDown(rgbaImage, mPyrDownMat);
    Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

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

    //Test whether we need two inRange operations (only if the hue crosses over 255)
    if (upperBound.getScalar().val[0] <= 255) {
        Core.inRange(mHsvMat, lowerBound.getScalar(), upperBound.getScalar(), mMask);
    } else {
        //We need two operations - we're going to OR the masks together
        Scalar lower = lowerBound.getScalar().clone();
        Scalar upper = upperBound.getScalar().clone();
        while (upper.val[0] > 255)
            upper.val[0] -= 255;
        double tmp = lower.val[0];
        lower.val[0] = 0;
        //Mask 1 - from 0 to n
        Core.inRange(mHsvMat, lower, upper, mMaskOne);
        //Mask 2 - from 255-n to 255
        lower.val[0] = tmp;
        upper.val[0] = 255;

        Core.inRange(mHsvMat, lower, upper, mMask);
        //OR the two masks
        Core.bitwise_or(mMaskOne, mMask, mMask);
    }

    //Dilate (blur) the mask to decrease processing power
    Imgproc.dilate(mMask, mDilatedMask, new Mat());

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

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

    // Filter contours by area and resize to fit the original image size
    contours.clear();
    for (MatOfPoint c : contourListTemp) {
        Core.multiply(c, new Scalar(4, 4), c);
        contours.add(new Contour(c));
    }
}