Example usage for org.opencv.imgproc Imgproc contourArea

List of usage examples for org.opencv.imgproc Imgproc contourArea

Introduction

In this page you can find the example usage for org.opencv.imgproc Imgproc contourArea.

Prototype

public static double contourArea(Mat contour, boolean oriented) 

Source Link

Usage

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

License:Open Source License

/**
 * On Camera Frame/*ww w . j  a v a 2 s.c  om*/
 * 
 * Process frame image through Rubik Face recognition possibly resulting in a state change.
 * 
 *  (non-Javadoc)
 * @see org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2#onCameraFrame(org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame)
 */
@Override
public Mat onCameraFrame(CvCameraViewFrame inputFrame) {

    //      Log.e(Constants.TAG, "CV Thread ID = " + Thread.currentThread().getId());

    // Just display error message if it is non-null.
    if (errorImage != null)
        return errorImage;

    Mat image = inputFrame.rgba();
    Size imageSize = image.size();
    Log.v(Constants.TAG_CAL, "Input Frame width=" + imageSize.width + " height=" + imageSize.height);
    if (imageSize.width != stateModel.openCVSize.width || imageSize.height != stateModel.openCVSize.height)
        Log.e(Constants.TAG_CAL, "State Model openCVSize does not agree with input frame!");

    // Save or Recall image as requested
    switch (MenuAndParams.imageSourceMode) {
    case NORMAL:
        break;
    case SAVE_NEXT:
        Util.saveImage(image);
        MenuAndParams.imageSourceMode = ImageSourceModeEnum.NORMAL;
        break;
    case PLAYBACK:
        image = Util.recallImage();
    default:
        break;
    }

    // Calculate and display Frames Per Second
    long newTimeStamp = System.currentTimeMillis();
    if (framesPerSecondTimeStamp > 0) {
        long frameTime = newTimeStamp - framesPerSecondTimeStamp;
        double framesPerSecond = 1000.0 / frameTime;
        String string = String.format("%4.1f FPS", framesPerSecond);
        Core.putText(image, string, new Point(50, 700), Constants.FontFace, 2, ColorTileEnum.WHITE.cvColor, 2);
    }
    framesPerSecondTimeStamp = newTimeStamp;

    try {

        // Initialize
        RubikFace rubikFace = new RubikFace();
        rubikFace.profiler.markTime(Profiler.Event.START);
        Log.i(Constants.TAG, "============================================================================");

        /* **********************************************************************
         * **********************************************************************
         * Return Original Image
         */
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.DIRECT) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            return annotation.drawAnnotation(image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Process to Grey Scale
         * 
         * This algorithm finds highlights areas that are all of nearly
         * the same hue.  In particular, cube faces should be highlighted.
         */
        Mat greyscale_image = new Mat();
        Imgproc.cvtColor(image, greyscale_image, Imgproc.COLOR_BGR2GRAY);
        rubikFace.profiler.markTime(Profiler.Event.GREYSCALE);
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.GREYSCALE) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            image.release();
            return annotation.drawAnnotation(greyscale_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Gaussian Filter Blur prevents getting a lot of false hits 
         */
        Mat blur_image = new Mat();

        int kernelSize = (int) MenuAndParams.gaussianBlurKernelSizeParam.value;
        kernelSize = kernelSize % 2 == 0 ? kernelSize + 1 : kernelSize; // make odd
        Imgproc.GaussianBlur(greyscale_image, blur_image, new Size(kernelSize, kernelSize), -1, -1);
        rubikFace.profiler.markTime(Profiler.Event.GAUSSIAN);
        greyscale_image.release();
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.GAUSSIAN) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            image.release();
            return annotation.drawAnnotation(blur_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Canny Edge Detection
         */
        Mat canny_image = new Mat();
        Imgproc.Canny(blur_image, canny_image, MenuAndParams.cannyLowerThresholdParam.value,
                MenuAndParams.cannyUpperThresholdParam.value, 3, // Sobel Aperture size.  This seems to be typically value used in the literature: i.e., a 3x3 Sobel Matrix.
                false); // use cheap gradient calculation: norm =|dI/dx|+|dI/dy|
        rubikFace.profiler.markTime(Profiler.Event.EDGE);
        blur_image.release();
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.CANNY) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            image.release();
            return annotation.drawAnnotation(canny_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Dilation Image Process
         */
        Mat dilate_image = new Mat();
        Imgproc.dilate(canny_image, dilate_image, Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(
                MenuAndParams.dilationKernelSizeParam.value, MenuAndParams.dilationKernelSizeParam.value)));
        rubikFace.profiler.markTime(Profiler.Event.DILATION);
        canny_image.release();
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.DILATION) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            image.release();
            return annotation.drawAnnotation(dilate_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Contour Generation 
         */
        List<MatOfPoint> contours = new LinkedList<MatOfPoint>();
        Mat heirarchy = new Mat();
        Imgproc.findContours(dilate_image, contours, heirarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); // Note: tried other TC89 options, but no significant change or improvement on cpu time.
        rubikFace.profiler.markTime(Profiler.Event.CONTOUR);
        dilate_image.release();

        // Create gray scale image but in RGB format, and then added yellow colored contours on top.
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.CONTOUR) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            Mat gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Mat rgba_gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Imgproc.cvtColor(image, gray_image, Imgproc.COLOR_RGB2GRAY);
            Imgproc.cvtColor(gray_image, rgba_gray_image, Imgproc.COLOR_GRAY2BGRA, 3);
            Imgproc.drawContours(rgba_gray_image, contours, -1, ColorTileEnum.YELLOW.cvColor, 3);
            Core.putText(rgba_gray_image, "Num Contours: " + contours.size(), new Point(500, 50),
                    Constants.FontFace, 4, ColorTileEnum.RED.cvColor, 4);
            gray_image.release();
            image.release();
            return annotation.drawAnnotation(rgba_gray_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Polygon Detection
         */
        List<Rhombus> polygonList = new LinkedList<Rhombus>();
        for (MatOfPoint contour : contours) {

            // Keep only counter clockwise contours.  A clockwise contour is reported as a negative number.
            double contourArea = Imgproc.contourArea(contour, true);
            if (contourArea < 0.0)
                continue;

            // Keep only reasonable area contours
            if (contourArea < MenuAndParams.minimumContourAreaParam.value)
                continue;

            // Floating, instead of Double, for some reason required for approximate polygon detection algorithm.
            MatOfPoint2f contour2f = new MatOfPoint2f();
            MatOfPoint2f polygone2f = new MatOfPoint2f();
            MatOfPoint polygon = new MatOfPoint();

            // Make a Polygon out of a contour with provide Epsilon accuracy parameter.
            // It uses the Douglas-Peucker algorithm http://en.wikipedia.org/wiki/Ramer-Douglas-Peucker_algorithm
            contour.convertTo(contour2f, CvType.CV_32FC2);
            Imgproc.approxPolyDP(contour2f, polygone2f, MenuAndParams.polygonEpsilonParam.value, // The maximum distance between the original curve and its approximation.
                    true); // Resulting polygon representation is "closed:" its first and last vertices are connected.
            polygone2f.convertTo(polygon, CvType.CV_32S);

            polygonList.add(new Rhombus(polygon));
        }

        rubikFace.profiler.markTime(Profiler.Event.POLYGON);

        // Create gray scale image but in RGB format, and then add yellow colored polygons on top.
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.POLYGON) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            Mat gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Mat rgba_gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Imgproc.cvtColor(image, gray_image, Imgproc.COLOR_RGB2GRAY);
            Imgproc.cvtColor(gray_image, rgba_gray_image, Imgproc.COLOR_GRAY2BGRA, 4);
            for (Rhombus polygon : polygonList)
                polygon.draw(rgba_gray_image, ColorTileEnum.YELLOW.cvColor);
            Core.putText(rgba_gray_image, "Num Polygons: " + polygonList.size(), new Point(500, 50),
                    Constants.FontFace, 3, ColorTileEnum.RED.cvColor, 4);
            return annotation.drawAnnotation(rgba_gray_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Rhombus Tile Recognition
         * 
         * From polygon list, produces a list of suitable Parallelograms (Rhombi).
         */
        Log.i(Constants.TAG, String.format("Rhombus:   X    Y   Area   a-a  b-a a-l b-l gamma"));
        List<Rhombus> rhombusList = new LinkedList<Rhombus>();
        // Get only valid Rhombus(es) : actually parallelograms.
        for (Rhombus rhombus : polygonList) {
            rhombus.qualify();
            if (rhombus.status == Rhombus.StatusEnum.VALID)
                rhombusList.add(rhombus);
        }

        // Filtering w.r.t. Rhmobus set characteristics
        Rhombus.removedOutlierRhombi(rhombusList);

        rubikFace.profiler.markTime(Profiler.Event.RHOMBUS);

        // Create gray scale image but in RGB format, and then add yellow colored Rhombi (parallelograms) on top.
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.RHOMBUS) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            Mat gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Mat rgba_gray_image = new Mat(imageSize, CvType.CV_8UC4);
            Imgproc.cvtColor(image, gray_image, Imgproc.COLOR_RGB2GRAY);
            Imgproc.cvtColor(gray_image, rgba_gray_image, Imgproc.COLOR_GRAY2BGRA, 4);
            for (Rhombus rhombus : rhombusList)
                rhombus.draw(rgba_gray_image, ColorTileEnum.YELLOW.cvColor);
            Core.putText(rgba_gray_image, "Num Rhombus: " + rhombusList.size(), new Point(500, 50),
                    Constants.FontFace, 4, ColorTileEnum.RED.cvColor, 4);
            gray_image.release();
            image.release();
            return annotation.drawAnnotation(rgba_gray_image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Face Recognition
         * 
         * Takes a collection of Rhombus objects and determines if a valid
         * Rubik Face can be determined from them, and then also determines 
         * initial color for all nine tiles. 
         */
        rubikFace.processRhombuses(rhombusList, image);
        Log.i(Constants.TAG, "Face Solution = " + rubikFace.faceRecognitionStatus);
        rubikFace.profiler.markTime(Profiler.Event.FACE);
        if (MenuAndParams.imageProcessMode == ImageProcessModeEnum.FACE_DETECT) {
            stateModel.activeRubikFace = rubikFace;
            rubikFace.profiler.markTime(Profiler.Event.TOTAL);
            return annotation.drawAnnotation(image);
        }

        /* **********************************************************************
         * **********************************************************************
         * Cube Pose Estimation
         * 
         * Reconstruct the Rubik Cube 3D location and orientation in GL space coordinates.
         */
        if (rubikFace.faceRecognitionStatus == FaceRecognitionStatusEnum.SOLVED) {

            // Obtain Cube Pose from Face Grid information.
            stateModel.cubePose = CubePoseEstimator.poseEstimation(rubikFace, image, stateModel);

            // Process measurement update on Kalman Filter (if it exists).
            KalmanFilter kalmanFilter = stateModel.kalmanFilter;
            if (kalmanFilter != null)
                kalmanFilter.measurementUpdate(stateModel.cubePose, System.currentTimeMillis());

            // Process measurement update on Kalman Filter ALSM (if it exists).
            KalmanFilterALSM kalmanFilterALSM = stateModel.kalmanFilterALSM;
            if (kalmanFilter != null)
                kalmanFilterALSM.measurementUpdate(stateModel.cubePose, System.currentTimeMillis());
        } else {
            stateModel.cubePose = null;
        }
        rubikFace.profiler.markTime(Profiler.Event.POSE);

        /* **********************************************************************
         * **********************************************************************
         * Application State Machine
         * 
         * Will provide user instructions.
         * Will determine when we are on-face and off-face
         * Will determine when we are on-new-face
         * Will change state 
         */
        appStateMachine.onFaceEvent(rubikFace);
        rubikFace.profiler.markTime(Profiler.Event.CONTROLLER);
        rubikFace.profiler.markTime(Profiler.Event.TOTAL);

        // Normal return point.
        stateModel.activeRubikFace = rubikFace;
        return annotation.drawAnnotation(image);

        // =+= Issue: how to get stdio to print as error and not warning in logcat?
    } catch (CvException e) {
        Log.e(Constants.TAG, "CvException: " + e.getMessage());
        e.printStackTrace();
        errorImage = new Mat(imageSize, CvType.CV_8UC4);
        Core.putText(errorImage, "CvException: " + e.getMessage(), new Point(50, 50), Constants.FontFace, 2,
                ColorTileEnum.WHITE.cvColor, 2);
        int i = 1;
        for (StackTraceElement element : e.getStackTrace())
            Core.putText(errorImage, element.toString(), new Point(50, 50 + 50 * i++), Constants.FontFace, 2,
                    ColorTileEnum.WHITE.cvColor, 2);
    } catch (Exception e) {
        Log.e(Constants.TAG, "Exception: " + e.getMessage());
        e.printStackTrace();
        errorImage = new Mat(imageSize, CvType.CV_8UC4);
        Core.putText(errorImage, "Exception: " + e.getMessage(), new Point(50, 50), Constants.FontFace, 2,
                ColorTileEnum.WHITE.cvColor, 2);
        int i = 1;
        for (StackTraceElement element : e.getStackTrace())
            Core.putText(errorImage, element.toString(), new Point(50, 50 + 50 * i++), Constants.FontFace, 2,
                    ColorTileEnum.WHITE.cvColor, 2);
    } catch (Error e) {
        Log.e(Constants.TAG, "Error: " + e.getMessage());
        e.printStackTrace();
        errorImage = new Mat(imageSize, CvType.CV_8UC4);
        Core.putText(errorImage, "Error: " + e.getMessage(), new Point(50, 50), Constants.FontFace, 2,
                ColorTileEnum.WHITE.cvColor, 2);
        int i = 1;
        for (StackTraceElement element : e.getStackTrace())
            Core.putText(errorImage, element.toString(), new Point(50, 50 + 50 * i++), Constants.FontFace, 2,
                    ColorTileEnum.WHITE.cvColor, 2);
    }

    return annotation.drawAnnotation(image);
}

From source file:usefull.detectContours.java

License:LGPL

public static void main(String[] args) throws InterruptedException {

    // load the Core OpenCV library by name

    System.loadLibrary(Core.NATIVE_LIBRARY_NAME);

    // load two image files

    Mat img1 = Highgui.imread("files/cctv_example1.png");
    Mat img2 = Highgui.imread("files/cctv_example2.png");

    // create a new image object to store image difference

    Mat diff_img = new Mat();

    // compute the difference between the images

    Core.absdiff(img1, img2, diff_img);/* ww  w .  ja va2  s  .  c o m*/

    // now convert it to grey and threshold it

    Mat grey = new Mat();
    Imgproc.cvtColor(diff_img, grey, Imgproc.COLOR_BGR2GRAY);

    Imgproc.adaptiveThreshold(grey, diff_img, 255, Imgproc.ADAPTIVE_THRESH_MEAN_C, Imgproc.THRESH_BINARY_INV, 7,
            10);

    // now clean it up using some morphological operations

    Size ksize = new Size(15, 15);
    Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, ksize);

    Imgproc.morphologyEx(diff_img, diff_img, Imgproc.MORPH_CLOSE, kernel);

    // find the all the contours from the binary image using the edge to contour
    // stuff we looked at in lectures

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

    Imgproc.findContours(diff_img, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);

    // draw the contours on image 2 in red

    Imgproc.drawContours(img2, contours, -1, new Scalar(0, 0, 255));

    // find the largest contour by area 

    double maxArea = 0;
    int maxAreaIndex = 0;

    for (int i = 0; i < contours.size(); i++) {

        double area = Imgproc.contourArea(contours.get(i), false);

        if (area > maxArea) {
            maxArea = area;
            maxAreaIndex = i;
        }
    }

    // draw the largest contour in red

    Imgproc.drawContours(img2, contours, maxAreaIndex, new Scalar(0, 255, 0));

    // create a new window objects

    Imshow ims1 = new Imshow("Image 1");
    Imshow ims2 = new Imshow("Image 2");
    Imshow ims_diff = new Imshow("Difference");

    // display images

    ims1.showImage(img1);
    ims2.showImage(img2);
    ims_diff.showImage(diff_img);

}