public boolean hasChanges(Mat current) { int PIXEL_DIFF_THRESHOLD = 5; int IMAGE_DIFF_THRESHOLD = 5; Mat bg = new Mat(); Mat cg = new Mat(); Mat diff = new Mat(); Mat tdiff = new Mat(); Imgproc.cvtColor(base, bg, Imgproc.COLOR_BGR2GRAY); Imgproc.cvtColor(current, cg, Imgproc.COLOR_BGR2GRAY); Core.absdiff(bg, cg, diff); Imgproc.threshold(diff, tdiff, PIXEL_DIFF_THRESHOLD, 0.0, Imgproc.THRESH_TOZERO); if (Core.countNonZero(tdiff) <= IMAGE_DIFF_THRESHOLD) { return false; } Imgproc.threshold(diff, diff, PIXEL_DIFF_THRESHOLD, 255, Imgproc.THRESH_BINARY); Imgproc.dilate(diff, diff, new Mat()); Mat se = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(5, 5)); Imgproc.morphologyEx(diff, diff, Imgproc.MORPH_CLOSE, se); List<MatOfPoint> points = new ArrayList<MatOfPoint>(); Mat contours = new Mat(); Imgproc.findContours(diff, points, contours, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); int n = 0; for (Mat pm : points) { log(lvl, "(%d) %s", n++, pm); printMatI(pm); } log(lvl, "contours: %s", contours); printMatI(contours); return true; }
/** * Finds and extracts all contours in the given Mat. Optionally also removes contours with areas * below that of MIN_CONTOUR_AREA. * * @param mask A mask of all resistors in the image * @param originalImage The original image from which the mask was created * @param thresholdByArea If true, remove contours below threshold * @return The list a found contours */ private List<MatOfPoint> getContours(Mat mask, Mat originalImage, boolean thresholdByArea) { List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); Imgproc.findContours( mask, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE, new Point(0, 0)); // remove any remaining noise by only keeping contours which area > threshold if (thresholdByArea) { for (int i = 0; i < contours.size(); i++) { double area = Imgproc.contourArea(contours.get(i)); if (area < MIN_CONTOUR_AREA || area > 6000) { contours.remove(i); i--; } } } Mat drawing = Mat.zeros(originalImage.size(), CvType.CV_8U); for (int i = 0; i < contours.size(); i++) { Scalar color = new Scalar(255, 255, 255); Imgproc.drawContours(drawing, contours, i, color, 4, 8, hierarchy, 0, new Point()); } paintBR(drawing); return contours; }
/** * Locate rectangles in an image * * @param grayImage Grayscale image * @return Rectangle locations */ public RectangleLocationResult locateRectangles(Mat grayImage) { Mat gray = grayImage.clone(); // Filter out some noise Filter.downsample(gray, 2); Filter.upsample(gray, 2); Mat cacheHierarchy = new Mat(); Mat grayTemp = new Mat(); List<Rectangle> rectangles = new ArrayList<>(); List<Contour> contours = new ArrayList<>(); Imgproc.Canny(gray, grayTemp, 0, THRESHOLD_CANNY, APERTURE_CANNY, true); Filter.dilate(gray, 2); List<MatOfPoint> contoursTemp = new ArrayList<>(); // Find contours - the parameters here are very important to compression and retention Imgproc.findContours( grayTemp, contoursTemp, cacheHierarchy, Imgproc.CV_RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); // For each contour, test whether the contour is a rectangle // List<Contour> contours = new ArrayList<>(); MatOfPoint2f approx = new MatOfPoint2f(); for (MatOfPoint co : contoursTemp) { MatOfPoint2f matOfPoint2f = new MatOfPoint2f(co.toArray()); Contour c = new Contour(co); // Attempt to fit the contour to the best polygon Imgproc.approxPolyDP( matOfPoint2f, approx, c.arcLength(true) * EPLISON_APPROX_TOLERANCE_FACTOR, true); Contour approxContour = new Contour(approx); // Make sure the contour is big enough, CLOSED (convex), and has exactly 4 points if (approx.toArray().length == 4 && Math.abs(approxContour.area()) > 1000 && approxContour.isClosed()) { // TODO contours and rectangles array may not match up, but why would they? contours.add(approxContour); // Check each angle to be approximately 90 degrees double maxCosine = 0; for (int j = 2; j < 5; j++) { double cosine = Math.abs( MathUtil.angle( approx.toArray()[j % 4], approx.toArray()[j - 2], approx.toArray()[j - 1])); maxCosine = Math.max(maxCosine, cosine); } if (maxCosine < MAX_COSINE_VALUE) { // Convert the points to a rectangle instance rectangles.add(new Rectangle(approx.toArray())); } } } return new RectangleLocationResult(contours, rectangles); }
private static Mat findLargestRectangle(Mat original_image) { Mat imgSource = original_image.clone(); // convert the image to black and white Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BGR2GRAY); // convert the image to black and white does (8 bit) Imgproc.Canny(imgSource, imgSource, 50, 50); // apply gaussian blur to smoothen lines of dots Imgproc.GaussianBlur(imgSource, imgSource, new Size(5, 5), 5); // find the contours List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours( imgSource, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); double maxArea = -1; MatOfPoint temp_contour = contours.get(0); // the largest is at the // index 0 for starting // point MatOfPoint2f approxCurve = new MatOfPoint2f(); List<MatOfPoint> largest_contours = new ArrayList<MatOfPoint>(); for (int idx = 0; idx < contours.size(); idx++) { temp_contour = contours.get(idx); double contourarea = Imgproc.contourArea(temp_contour); // compare this contour to the previous largest contour found if (contourarea > maxArea) { // check if this contour is a square MatOfPoint2f new_mat = new MatOfPoint2f(temp_contour.toArray()); int contourSize = (int) temp_contour.total(); Imgproc.approxPolyDP(new_mat, approxCurve, contourSize * 0.05, true); if (approxCurve.total() == 4) { maxArea = contourarea; largest_contours.add(temp_contour); } } } MatOfPoint temp_largest = largest_contours.get(largest_contours.size() - 1); largest_contours = new ArrayList<MatOfPoint>(); largest_contours.add(temp_largest); // Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BayerBG2RGB); Imgproc.drawContours(original_image, largest_contours, -1, new Scalar(0, 255, 0), 10); // Mat perspectiveTransform = new Mat(3, 3, CvType.CV_32FC1); // Imgproc.warpPerspective(original_image, imgSource, // perspectiveTransform, new Size(300,300)); Highgui.imwrite(output, original_image); // create the new image here using the largest detected square // Toast.makeText(getApplicationContext(), "Largest Contour: ", // Toast.LENGTH_LONG).show(); return imgSource; }
public static Mat getCCH(Mat image) { ArrayList<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); Imgproc.findContours( image, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_NONE); Mat chainHistogram = Mat.zeros(1, 8, CvType.CV_32F); int n = 0; MatOfPoint2f approxCurve = new MatOfPoint2f(); for (MatOfPoint contour : contours) { // get the freeman chain code from the contours int rows = contour.rows(); // System.out.println("\nrows"+rows+"\n"+contour.dump()); int direction = 7; Mat prevPoint = contours.get(0).row(0); n += rows - 1; for (int i = 1; i < rows; i++) { // get the current point double x1 = contour.get(i - 1, 0)[1]; double y1 = contour.get(i - 1, 0)[0]; // get the second point double x2 = contour.get(i, 0)[1]; double y2 = contour.get(i, 0)[0]; if (x2 == x1 && y2 == y1 + 1) direction = 0; else if (x2 == x1 - 1 && y2 == y1 + 1) direction = 1; else if (x2 == x1 - 1 && y2 == y1) direction = 2; else if (x2 == x1 - 1 && y2 == y1 - 1) direction = 3; else if (x2 == x1 && y2 == y1 - 1) direction = 4; else if (x2 == x1 + 1 && y2 == y1 - 1) direction = 5; else if (x2 == x1 + 1 && y2 == y1) direction = 6; else if (x2 == x1 + 1 && y2 == y1 + 1) direction = 7; else System.out.print("err"); double counter = chainHistogram.get(0, direction)[0]; chainHistogram.put(0, direction, ++counter); System.out.print(direction); } } System.out.println("\n" + chainHistogram.dump()); Scalar alpha = new Scalar(n); // the factor Core.divide(chainHistogram, alpha, chainHistogram); System.out.println("\nrows=" + n + " " + chainHistogram.dump()); return chainHistogram; }
private boolean findMarkers( Mat imgMat, DtouchMarker marker, ArrayList<MatOfPoint> components, Mat hierarchy) { boolean markerFound = false; // holds all the markers identified in the camera. List<DtouchMarker> markersDetected = new ArrayList<DtouchMarker>(); Mat contourImg = imgMat.clone(); // Find blobs using connect component. Imgproc.findContours( contourImg, components, hierarchy, Imgproc.RETR_TREE, Imgproc.CHAIN_APPROX_NONE); // No need to use contourImg so release it. contourImg.release(); List<Integer> code = new ArrayList<Integer>(); for (int i = 0; i < components.size(); i++) { // clean this list. code.clear(); if (markerDetector.verifyRoot(i, hierarchy, code)) { // if marker found then add in the list. DtouchMarker markerDetected = new DtouchMarker(); markerDetected.setCode(code); markerDetected.setComponentIndex(i); markersDetected.add(markerDetected); } } // if markers are found then decide which marker code occurred most. if (markersDetected.size() > 0) { DtouchMarker markerSelected = markerDetector.compareDetectedMarkers(markersDetected); if (markerSelected != null) { marker.setCode(markerSelected.getCode()); marker.setComponentIndex(markerSelected.getComponentIndex()); markerFound = true; } } return markerFound; }
/** * calculates the center of mass using <code>colorForTrackingHSV</code> and <code>colorRadius * </code> as radius (in HSV-color space) * * @param hsv the frame of which the center of mass should be calculated off * @return the center of mass as a point in pixel coordinates (i.e. integer) */ public Point calcCenterOfMass(Mat hsv) { blackWhiteMask = new Mat(); Core.inRange(hsv, lowerBound, upperBound, blackWhiteMask); dilatedMask = new Mat(); Imgproc.dilate(blackWhiteMask, dilatedMask, new Mat()); contour = new ArrayList<MatOfPoint>(); Mat mHierarchy = new Mat(); Mat tempDilatedMask = dilatedMask.clone(); Imgproc.findContours( tempDilatedMask, contour, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE); boundingRect = Imgproc.boundingRect(findLargestContour(contour)); int centerOfMassX = boundingRect.x + boundingRect.width / 2; int centerOfMassY = boundingRect.y + boundingRect.height / 2; Point centerOfMass = new Point(centerOfMassX, centerOfMassY); trackPath.add(centerOfMass); return centerOfMass; }
/** * Locate ellipses within an image * * @param grayImage Grayscale image * @return Ellipse locations */ public EllipseLocationResult locateEllipses(Mat grayImage) { Mat gray = grayImage.clone(); Filter.downsample(gray, 2); Filter.upsample(gray, 2); Imgproc.Canny(gray, gray, 5, 75, 3, true); Filter.dilate(gray, 2); Mat cacheHierarchy = new Mat(); List<MatOfPoint> contoursTemp = new ArrayList<>(); // Find contours - the parameters here are very important to compression and retention Imgproc.findContours( gray, contoursTemp, cacheHierarchy, Imgproc.CV_RETR_TREE, Imgproc.CHAIN_APPROX_TC89_KCOS); // List contours List<Contour> contours = new ArrayList<>(); for (MatOfPoint co : contoursTemp) { contours.add(new Contour(co)); } // Find ellipses by finding fit List<Ellipse> ellipses = new ArrayList<>(); for (MatOfPoint co : contoursTemp) { contours.add(new Contour(co)); // Contour must have at least 6 points for fitEllipse if (co.toArray().length < 6) continue; // Copy MatOfPoint to MatOfPoint2f MatOfPoint2f matOfPoint2f = new MatOfPoint2f(co.toArray()); // Fit an ellipse to the current contour Ellipse ellipse = new Ellipse(Imgproc.fitEllipse(matOfPoint2f)); // Draw ellipse ellipses.add(ellipse); } return new EllipseLocationResult(contours, ellipses); }
/** * Determines which pieces are kings * * @param in Mat image of board */ public void determineKings(Mat in) { int playSquares = 32; Mat dst = new Mat(in.rows(), in.cols(), in.type()); in.copyTo(dst); Imgproc.cvtColor(dst, dst, Imgproc.COLOR_BGR2GRAY); // change to single color Mat canny = new Mat(); Imgproc.Canny(dst, canny, 100, 200); // make image a canny image that is only edges; 2,4 // lower threshold values find more edges List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); // holds nested contour information Imgproc.findContours( canny, contours, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); // Imgproc.RETR_LIST, TREE // draw contour image Mat mask = new Mat(); mask = Mat.zeros(dst.size(), dst.type()); Imgproc.drawContours( mask, contours, -1, new Scalar(255, 255, 255), 1, 8, hierarchy, 2, new Point()); Highgui.imwrite("contours.jpg", mask); ArrayList occupied = new ArrayList<Integer>(); for (int i = 0; i < playSquares; i++) { if (board[i] != 0) occupied.add(i); } for (int i = 0; i < contours.size(); i++) // assuming only contours are checker pieces { // determine if it should be a king // use Rect r = Imgproc.boundingRect then find height of it by r.height // Get bounding rect of contour Rect bound = Imgproc.boundingRect(contours.get(i)); if (bound.height > in.rows() / 8) { // board[(int) occupied.get(0)]++; // make it a king // occupied.remove(0); } } // or apply to each region of interest /* // keep track of starting row square int parity = 0; // 0 is even, 1 is odd, tied to row number int count = 0; // row square int rowNum = 0; // row number, starting at 0 int vsegment = in.rows() / 8; // only accounts 8 playable int hsegment = in.cols() / 12; // 8 playable, 2 capture, 2 extra int offset = hsegment * 2; // offset for playable board // For angle of camera int dx = 48; hsegment -= 8; // Go through all playable squares for (int i = 0; i < playSquares; i++) { // change offset depending on the row if (parity == 0) // playable squares start on immediate left offset = hsegment * 3 + dx; else // playable squares start on 2nd square from left offset = hsegment * 2 + dx; // find where roi should be Point p1 = new Point(offset + count * hsegment, rowNum * vsegment); // top left point of rectangle (x,y) Point p2 = new Point(offset + (count + 1) * hsegment, (rowNum + 1) * vsegment); // bottom right point of rectangle (x,y) // create rectangle that is board square Rect bound = new Rect(p1, p2); // frame only includes rectangle Mat roi = new Mat(in, bound); Imgproc.cvtColor(roi, roi, Imgproc.COLOR_BGR2GRAY); // change to single color Mat canny = new Mat(); Imgproc.Canny(roi, canny, 2, 4); // make image a canny image that is only edges; 2,4 // lower threshold values find more edges List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); // holds nested contour information Imgproc.findContours(canny, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE); // Imgproc.RETR_LIST, TREE // Get bounding rect of contour Rect rect = Imgproc.boundingRect(contours.get(0)); if (rect.height > in.rows() / 8) { board[i]++; // make it a king } count += 2; if (count == 8) { parity = ++parity % 2; // change odd or even count = 0; rowNum++; hsegment += 1; dx -= 6; } }*/ }
public static int identify_R_U(Mat binary) { // 0: hull points identified < 2 // 1: R // 2: U List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); List<MatOfPoint> hullPoints = new ArrayList<MatOfPoint>(); List<Point> hullPointList = new ArrayList<Point>(); List<Point> filteredPointList = new ArrayList<Point>(); MatOfPoint hullPointMat = new MatOfPoint(); MatOfInt hull = new MatOfInt(); Mat hierarchy = new Mat(); // Find contour Imgproc.findContours( binary, contours, hierarchy, Imgproc.RETR_TREE, Imgproc.CHAIN_APPROX_SIMPLE); // Find convex hull for (int k = 0; k < contours.size(); k++) { Imgproc.convexHull(contours.get(k), hull); for (int j = 0; j < hull.toList().size(); j++) { hullPointList.add(contours.get(k).toList().get(hull.toList().get(j))); } hullPointMat.fromList(hullPointList); hullPoints.add(hullPointMat); } // Filter hull points. Only hull points relevant to hull classification // will remain. // Also, count the number of filtered hull points in left and right. for (int l = 0; l < hullPointList.size(); l++) { if (hullPointList.get(l).y < binary.rows() * 0.25) { if (l != hullPointList.size() - 1) { if (Math.hypot( hullPointList.get(l).x - hullPointList.get(l + 1).x, hullPointList.get(l).y - hullPointList.get(l + 1).y) / binary.cols() > 0.08) { filteredPointList.add(hullPointList.get(l)); // Core.circle(rgb, // new Point(UL.x + hullPointList.get(l).x, UL.y // + hullPointList.get(l).y), 5, // new Scalar(0, 255, 0)); } } } } // Sort points by x axis, increasing if (filteredPointList.size() > 1) { if (filteredPointList.get(0).x > filteredPointList.get(1).x) { Point temp = filteredPointList.get(0); filteredPointList.set(0, filteredPointList.get(1)); filteredPointList.set(1, temp); } if (filteredPointList.get(0).y > filteredPointList.get(1).y) return 1; // R else return 2; // U } return 0; }
public Mat onCameraFrame(CvCameraViewFrame inputFrame) { mRgba = inputFrame.rgba(); // convert to Gray scale Imgproc.cvtColor(mRgba, img_gray, Imgproc.COLOR_BGR2GRAY); // make it binary with threshold=100 Imgproc.threshold(img_gray, erd, 100, 255, Imgproc.THRESH_OTSU); // remove pixel noise by "erode" with structuring element of 9X9 Mat erode = Imgproc.getStructuringElement(Imgproc.MORPH_ERODE, new Size(9, 9)); Imgproc.erode(erd, tgt, erode); // apply "dilation" to enlarge object Mat dilate = Imgproc.getStructuringElement(Imgproc.MORPH_DILATE, new Size(9, 9)); Imgproc.dilate(tgt, erd, dilate); // take a window Size s = erd.size(); int W = (int) s.width; int H = (int) s.height; Rect r = new Rect(0, H / 2 - 100, W, 200); Mat mask = new Mat(s, CvType.CV_8UC1, new Scalar(0, 0, 0)); rectangle(mask, r.tl(), r.br(), new Scalar(255, 255, 255), -1); erd.copyTo(window, mask); // find the contours Imgproc.findContours(window, contours, dest, 0, 2); // find largest contour int maxContour = -1; double area = 0; for (int i = 0; i < contours.size(); i++) { double contArea = Imgproc.contourArea(contours.get(i)); if (contArea > area) { area = contArea; maxContour = i; } } // form bounding rectangle for largest contour Rect rect = null; if (maxContour > -1) rect = Imgproc.boundingRect(contours.get(maxContour)); // position to center while (!train) { if (rect != null) { Imgproc.rectangle(mRgba, rect.tl(), rect.br(), new Scalar(255, 255, 255), 5); if ((rect.x + rect.width / 2) > W / 2 - 20 && (rect.x + rect.width / 2) < W / 2 + 20) { runOnUiThread( new Runnable() { @Override public void run() { Toast.makeText(getApplicationContext(), "OK", Toast.LENGTH_SHORT).show(); } }); train = true; } } if (contours != null) contours.clear(); return mRgba; } if (train) { if (rect != null) { Imgproc.rectangle(mRgba, rect.tl(), rect.br(), new Scalar(255, 255, 255), 5); // direction of movement int thr = 100; if ((rect.x + rect.width / 2) < (W / 2 - thr)) { // move to the RIGHT uHandler.obtainMessage(MainActivity.LEFT).sendToTarget(); } else { if ((rect.x + rect.width / 2) > (W / 2 + thr)) { uHandler.obtainMessage(MainActivity.RIGHT).sendToTarget(); } else { uHandler.obtainMessage(MainActivity.FORWARD).sendToTarget(); } } } else { // stop moving uHandler.obtainMessage(MainActivity.STOP).sendToTarget(); } } if (contours != null) contours.clear(); return mRgba; }
public void processImage(Mat imageToProcess) { try { final Mat processedImage = imageToProcess.clone(); // red final Mat redUpper = new Mat(); final Mat redLower = new Mat(); Core.inRange(processedImage, new Scalar(170, 100, 20), new Scalar(180, 255, 255), redUpper); Core.inRange(processedImage, new Scalar(0, 100, 20), new Scalar(20, 255, 255), redLower); Core.bitwise_or(redLower, redUpper, processedImage); // refining the binary image Imgproc.erode(processedImage, processedImage, new Mat(), new Point(-1, -1), 1); Imgproc.dilate(processedImage, processedImage, new Mat(), new Point(-1, -1), 0); // create a clone for the processedImage to be used in finding contours final Mat clone = processedImage.clone(); Imgproc.cvtColor(processedImage, processedImage, Imgproc.COLOR_GRAY2RGB); // finds list of contours and draw the biggest on the processedImage final Scalar color1 = new Scalar(0, 0, 255); final Scalar color2 = new Scalar(255, 255, 0); final Scalar color3 = new Scalar(255, 255, 255); final List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours( clone, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_NONE); final List<MatOfPoint> contour = new ArrayList<MatOfPoint>(1); double maxArea = 0.0; for (int index = 0; index < contours.size(); index++) { double area = Imgproc.contourArea(contours.get(index)); if (area > maxArea && area > 25 && Imgproc.boundingRect(contours.get(index)).y > 40) { maxArea = area; contour.add(0, contours.get(index)); } } // finds bounding Rectangle and draws contours Rect boundingRect = new Rect(); if (contour.size() > 0) { Imgproc.drawContours(processedImage, contour, -2, color1); boundingRect = Imgproc.boundingRect(contour.get(0)); final double x = boundingRect.x; final double y = boundingRect.y; final double width = boundingRect.width; final double height = boundingRect.height; Core.rectangle(processedImage, new Point(x, y), new Point(x + width, y + height), color3); } // finding bounding Circle and draws it final Point center = new Point(); final float[] radius = new float[1]; if (contour.size() > 0) { final MatOfPoint2f contour2f = new MatOfPoint2f(contour.get(0).toArray()); Imgproc.minEnclosingCircle(contour2f, center, radius); Core.circle(processedImage, center, (int) radius[0], color2); } final BallStruct redBallStruct = new BallStruct(boundingRect, center, (double) radius[0]); final BallTargeting ballTargeting = new BallTargeting(redBallStruct); synchronized (this) { distanceToRed = ballTargeting.getDistance(); angleToRedInDegrees = ballTargeting.getAngle() * (180 / Math.PI); this.processedImage = processedImage; } } catch (Exception e) { } }
public void process(Mat rgbaImage) { Mat pyrDownMat = new Mat(); Imgproc.pyrDown(rgbaImage, pyrDownMat); Imgproc.pyrDown(pyrDownMat, pyrDownMat); Mat hsvMat = new Mat(); Imgproc.cvtColor(pyrDownMat, hsvMat, Imgproc.COLOR_RGB2HSV_FULL); Mat Mask = new Mat(); Core.inRange(hsvMat, mLowerBound, mUpperBound, Mask); Mat dilatedMask = new Mat(); Imgproc.dilate(Mask, dilatedMask, new Mat()); List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); Imgproc.findContours( dilatedMask, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE); blobCenters[0] = new Point(); blobCenters[1] = new Point(); if (contours.size() > 0) { // Find max contour area of the two biggest double[] maxArea = new double[2]; maxArea[0] = 0; // biggest maxArea[1] = 0; // 2nd biggest Iterator<MatOfPoint> each = contours.iterator(); int[] contourIndex = new int[2]; contourIndex[0] = 0; contourIndex[1] = 0; int index = 0; while (each.hasNext()) { MatOfPoint wrapper = each.next(); double area = Imgproc.contourArea(wrapper); if (area > maxArea[0]) { // area bigger than the maximum found maxArea[1] = maxArea[0]; contourIndex[1] = contourIndex[0]; maxArea[0] = area; contourIndex[0] = index; } else if (area > maxArea[1]) { // area bigger than the second maximum found maxArea[1] = area; contourIndex[1] = index; } index++; } // // another possibility to iterate through contours // for (index = 0; index < contours.size(); index++) { // d = Imgproc.contourArea (contours.get(index)); Log.d("index0", Integer.toString(contourIndex[0])); Log.d("index1", Integer.toString(contourIndex[1])); MatOfPoint2f mMOP2f1 = new MatOfPoint2f(); float[] radius = new float[contours.size()]; // contours is a List<MatOfPoint> // so contours.get(x) is a single MatOfPoint // but to use approxPolyDP we need to pass a MatOfPoint2f // so we need to do a conversion contours.get(contourIndex[0]).convertTo(mMOP2f1, CvType.CV_32FC2); // get the center of the bigger contour found Point tempCenter = new Point(); Imgproc.minEnclosingCircle(mMOP2f1, tempCenter, radius); blobCenters[0].x = tempCenter.x; blobCenters[0].y = tempCenter.y; blobRadius[0] = radius[0]; Log.d("center0.x", Double.toString(blobCenters[0].x)); Log.d("center0.y", Double.toString(blobCenters[0].y)); Log.d("radius0", Double.toString(blobRadius[0])); contours.get(contourIndex[1]).convertTo(mMOP2f1, CvType.CV_32FC2); Imgproc.minEnclosingCircle(mMOP2f1, tempCenter, radius); blobCenters[1].x = tempCenter.x; blobCenters[1].y = tempCenter.y; blobRadius[1] = radius[0]; Log.d("center1.x", Double.toString(blobCenters[1].x)); Log.d("center1.y", Double.toString(blobCenters[1].y)); Log.d("radius1", Double.toString(blobRadius[1])); // 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[1]) { Core.multiply(contour, new Scalar(4, 4), contour); mContours.add(contour); } } } else { blobCenters[0].x = 0; blobCenters[0].y = 0; blobCenters[1].x = 0; blobCenters[1].y = 0; } }
public static void getSquare(Mat imgSource) { Mat sourceImage = imgSource.clone(); Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BGR2GRAY); // convert the image to black and white does (8 bit) Imgproc.Canny(imgSource, imgSource, 50, 50); // apply gaussian blur to smoothen lines of dots Imgproc.GaussianBlur(imgSource, imgSource, new org.opencv.core.Size(5, 5), 5); // find the contours List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours( imgSource, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); double maxArea = -1; int maxAreaIdx = -1; // Log.d("size",Integer.toString(contours.size())); MatOfPoint temp_contour = contours.get(0); // the largest is at the // index 0 for starting // point MatOfPoint2f approxCurve = new MatOfPoint2f(); MatOfPoint largest_contour = contours.get(0); // largest_contour.ge List<MatOfPoint> largest_contours = new ArrayList<MatOfPoint>(); // Imgproc.drawContours(imgSource,contours, -1, new Scalar(0, 255, 0), // 1); for (int idx = 0; idx < contours.size(); idx++) { temp_contour = contours.get(idx); double contourarea = Imgproc.contourArea(temp_contour); // compare this contour to the previous largest contour found if (contourarea > maxArea) { // check if this contour is a square MatOfPoint2f new_mat = new MatOfPoint2f(temp_contour.toArray()); int contourSize = (int) temp_contour.total(); MatOfPoint2f approxCurve_temp = new MatOfPoint2f(); Imgproc.approxPolyDP(new_mat, approxCurve_temp, contourSize * 0.05, true); if (approxCurve_temp.total() == 4) { maxArea = contourarea; maxAreaIdx = idx; approxCurve = approxCurve_temp; largest_contour = temp_contour; } } } Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BayerBG2RGB); double[] temp_double; temp_double = approxCurve.get(0, 0); Point p1 = new Point(temp_double[0], temp_double[1]); // Core.circle(imgSource,p1,55,new Scalar(0,0,255)); // Imgproc.warpAffine(sourceImage, dummy, rotImage,sourceImage.size()); temp_double = approxCurve.get(1, 0); Point p2 = new Point(temp_double[0], temp_double[1]); // Core.circle(imgSource,p2,150,new Scalar(255,255,255)); temp_double = approxCurve.get(2, 0); Point p3 = new Point(temp_double[0], temp_double[1]); // Core.circle(imgSource,p3,200,new Scalar(255,0,0)); temp_double = approxCurve.get(3, 0); Point p4 = new Point(temp_double[0], temp_double[1]); // Core.circle(imgSource,p4,100,new Scalar(0,0,255)); List<Point> source = getCorners(p1, p2, p3, p4); for (Point p : source) { // System.out.println(p); } Mat startM = Converters.vector_Point2f_to_Mat(source); // Imgproc.cvtColor(sourceImage, sourceImage, Imgproc.COLOR_BGR2GRAY); Mat result = warp(sourceImage, startM, 5); // result = warp(result,result,1); // Imgproc.cvtColor(result, result, Imgproc.COLOR_BGR2GRAY); Highgui.imwrite(output, result); // System.out.println("Done"); // return result; }
public MatOfPoint getContourOfBestMatch() { if (matches == null) return null; Mat threshold = new Mat(imgGray.size(), imgGray.type()); Imgproc.threshold(imgGray, threshold, 70, 255, Imgproc.THRESH_TOZERO); List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours( threshold, contours, new Mat(), Imgproc.RETR_CCOMP, Imgproc.CHAIN_APPROX_NONE); // HashMap<Integer,MatOfPoint> coordinates = computeCoord(contours,) if (contours.size() == 0) return null; List<DMatch> matchList = matches.toList(); List<KeyPoint> keyPointList = keyPointImg.toList(); HashMap<Integer, Double> contourDensityMap = new HashMap<Integer, Double>(); Log.i("getContourBestMatch::", "contour size::" + contours.size()); for (int idx = 0; idx < contours.size(); idx++) { MatOfPoint2f ctr2f = new MatOfPoint2f(contours.get(idx).toArray()); // double contourarea = Imgproc.contourArea(contours.get(idx)); double contourarea = contours.get(idx).rows(); if (contourarea < 50) continue; Rect r = Imgproc.boundingRect(contours.get(idx)); double count = 0; // Log.i("contour area","contour area is::"+contourarea); for (DMatch match : matchList) { Point q = keyPointList.get(match.queryIdx).pt; if (q.x >= r.x && q.x <= (r.x + r.width) && q.y >= r.y && q.y <= (r.y + r.height)) count++; // // if(Imgproc.pointPolygonTest(ctr2f,keyPointList.get(match.queryIdx).pt,true)>0){ // if(null ==contourDensityMap.get(idx)) // contourDensityMap.put(idx,1.0); // // else{ // contourDensityMap.put(idx,((Double)contourDensityMap.get(idx))+1); // } // // } } // if(contourDensityMap.containsKey(idx)) { // // Log.i("contourPoint","idx::"+idx+"count::"+contourDensityMap.get(idx)+"contour // area::"+contourarea); // contourDensityMap.put(idx, contourDensityMap.get(idx) / contourarea); // } if (count != 0) { contourDensityMap.put(idx, count / contourarea); } } Log.i("MarkerTracker", "contour density size::" + contourDensityMap.size()); Map.Entry<Integer, Double> maxEntry = null; for (Map.Entry<Integer, Double> entry : contourDensityMap.entrySet()) { Log.i("contourDensityMap", "Entry value::" + entry.getValue()); if (maxEntry == null || entry.getValue().compareTo(maxEntry.getValue()) > 0) { maxEntry = entry; } } Log.i("maxEntry::", "" + (maxEntry == null ? null : maxEntry.getKey())); // return contours; return contours.get(maxEntry != null ? maxEntry.getKey() : 0); }
public void processWithContours(Mat in, Mat out) { int playSquares = 32; // number of playable game board squares // keep track of starting row square int parity = 0; // 0 is even, 1 is odd, tied to row number int count = 0; // row square int rowNum = 0; // row number, starting at 0 int vsegment = in.rows() / 8; // only accounts 8 playable int hsegment = in.cols() / 10; // 8 playable, 2 capture int hOffset = hsegment * 2; // offset for playable board int vOffset = vsegment + 40; // For angle of camera int dx = 80; int ddx = 0; hsegment -= 16; int dy = 20; vsegment -= 24; int ddy = 0; // Go through all playable squares for (int i = 0; i < playSquares; i++) { // change offset depending on the row if (parity == 0) // playable squares start on 2nd square from left { if (rowNum >= 5) dx -= 3; hOffset = hsegment * 2 + dx; } else // playable squares start on immediate left { if (rowNum >= 5) dx -= 3; hOffset = hsegment + dx; } if (rowNum == 0) ddy = 5; if (rowNum == 4) if (count == 6) ddx = 10; if (rowNum == 5) { if (count == 0) ddx = -6; else if (count == 2) ddx = 6; else if (count == 4) ddx = 12; else if (count == 6) ddx = 20; } if (rowNum == 6) { if (count == 0) ddx = 0; else if (count == 2) ddx = 16; else if (count == 4) ddx = 32; else if (count == 6) ddx = 40; } if (rowNum == 7) { if (count == 0) ddx = 6; else if (count == 2) ddx = 24; else if (count == 4) ddx = 40; else ddx = 52; } // find where roi should be // System.out.println("" + vOffset); Point p1 = new Point( hOffset + count * hsegment + ddx + 5, vOffset + rowNum * vsegment - dy - 5 - ddy); // top left point of rectangle (x,y) Point p2 = new Point( hOffset + (count + 1) * hsegment + ddx - 5, vOffset + (rowNum + 1) * vsegment - dy - 5 - ddy); // bottom right point of rectangle (x,y) // create rectangle that is board square Rect bound = new Rect(p1, p2); Mat roi; char color; if (i == 0) { // frame only includes rectangle roi = new Mat(in, bound); // get the color color = identifyColor(roi); // copy input image to output image in.copyTo(out); } else { // frame only includes rectangle roi = new Mat(out, bound); // get the color color = identifyColor(roi); } Imgproc.cvtColor(roi, roi, Imgproc.COLOR_BGR2GRAY); // change to single color Mat canny = new Mat(); Imgproc.Canny(roi, canny, 20, 40); // make image a canny image that is only edges; 2,4 // lower threshold values find more edges List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); // holds nested contour information Imgproc.findContours( canny, contours, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); // Imgproc.RETR_LIST, TREE System.out.println(++test + "\t" + contours.size()); if (contours.size() > 3) // or error value for color is below 1 { switch (color) { case COLOR_BLUE: // Imgproc.rectangle(out, p1, p2, new Scalar(255, 0, 0), 2); Core.rectangle(out, p1, p2, new Scalar(255, 0, 0), 2); board[i] = CheckersBoard.BLACK; // end user's piece break; case COLOR_ORANGE: // Imgproc.rectangle(out, p1, p2, new Scalar(0, 128, 255), 2); Core.rectangle(out, p1, p2, new Scalar(0, 128, 255), 2); board[i] = CheckersBoard.WHITE; // system's piece break; case COLOR_WHITE: // Imgproc.rectangle(out, p1, p2, new Scalar(255, 255, 255), 2); Core.rectangle(out, p1, p2, new Scalar(255, 255, 255), 2); board[i] = CheckersBoard.EMPTY; break; case COLOR_BLACK: // this is black // Imgproc.rectangle(out, p1, p2, new Scalar(0, 0, 0), 2); Core.rectangle( out, p1, p2, new Scalar(0, 0, 0), 2); // maybe add 8, 0 as line type and fractional bits board[i] = CheckersBoard.EMPTY; break; } } System.out.println("in color switch " + board[i]); count += 2; if (count == 8) { parity = ++parity % 2; // change odd or even count = 0; rowNum++; hsegment += 2; dx -= 10; dy += 10; vsegment += 3; ddy = 0; } } }
/** * detection_contours, détecte les contours, les affiches et gères le traitement * d'authentification * * @param inmat : la matrice qui arrive pour la detection de contour * @param outmat : la matrice qui sort après les comptours */ public void detection_contours(Mat inmat, Mat outmat) { Mat v = new Mat(); Mat vv = outmat.clone(); List<MatOfPoint> contours = new ArrayList(); // Tous les contours int key; // Plus gros contours MatOfInt hullI = new MatOfInt(); List<MatOfPoint> hullP = new ArrayList<MatOfPoint>(); Rect r; // Rectangle du plus gros contours // Trouve tous les contours Imgproc.findContours(vv, contours, v, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); // Calcul l'indice du plus gros contours key = findBiggestContour(contours); // S'il y a au moins un contours et le if (key != 0) { Imgproc.drawContours(inmat, contours, key, new Scalar(0, 0, 255)); r = Imgproc.boundingRect(contours.get(key)); Core.rectangle(currentFrame, r.br(), r.tl(), new Scalar(0, 255, 0), 1); } // Calcul les points convexes de la main Imgproc.convexHull(contours.get(key), hullI, false); // S'il y a des points de convexion if (hullI != null) { // Reinitialise les points de convexion hullP.clear(); // On calcule le nombres de points de convexion for (int i = 0; contours.size() >= i; i++) hullP.add(new MatOfPoint()); int[] cId = hullI.toArray(); // On récupère dans un tableau de points, les points du contours Point[] contourPts = contours.get(key).toArray(); // Réinitialisation des points de recherche dans les tableau int findRectA = 0; int findRectB = 0; int findRectC = 0; int findRectD = 0; // Pour chaque point de convexion for (int i = 0; i < cId.length; i++) { // Dessin du point de convexion sur la matrice Core.circle(inmat, contourPts[cId[i]], 2, new Scalar(241, 247, 45), -3); // Si le point de convexion se trouve dans un des carrés // on incrémente le compteur associé if (isInRectangle(rectA, contourPts[cId[i]])) findRectA++; else if (isInRectangle(rectB, contourPts[cId[i]])) findRectB++; else if (isInRectangle(rectC, contourPts[cId[i]])) findRectC++; else if (isInRectangle(rectD, contourPts[cId[i]])) findRectD++; } // Si on a trouvé la main dans le rectangle A if (findRectA >= 5) { if (cptRect == 0) { numeroRect[cptRect] = 1; cptRect++; System.out.println("Haut gauche"); } else { if (numeroRect[cptRect - 1] != 1) { numeroRect[cptRect] = 1; if (cptRect == 3) cptRect = 0; else cptRect++; System.out.println("Haut gauche"); } } } // Si on a trouvé la main dans le rectangle B if (findRectB >= 5) { if (cptRect == 0) { numeroRect[cptRect] = 2; cptRect++; System.out.println("Bas gauche"); } else { if (numeroRect[cptRect - 1] != 2) { numeroRect[cptRect] = 2; if (cptRect == 3) cptRect = 0; else cptRect++; System.out.println("Bas gauche"); } } } // Si on a trouvé la main dans le rectangle C if (findRectC >= 5) { if (cptRect == 0) { numeroRect[cptRect] = 3; if (cptRect == 3) cptRect = 0; else cptRect++; System.out.println("Haut droite"); } else { if (numeroRect[cptRect - 1] != 3) { numeroRect[cptRect] = 3; if (cptRect == 3) cptRect = 0; else cptRect++; System.out.println("Haut droite"); } } } // Si on a trouvé la main dans le rectangle D if (findRectD >= 5) { if (cptRect == 0) { numeroRect[cptRect] = 4; cptRect++; System.out.println("Bas droite"); } else { if (numeroRect[cptRect - 1] != 4) { numeroRect[cptRect] = 4; if (cptRect == 3) cptRect = 0; else cptRect++; System.out.println("Bas droite"); } } } // Si on a sélectionné 3 fenètres et que cela correspond au mot de passe // MOT DE PASSE : Haut Gauche - Bas Droite - Bas Gauche if (cptRect == 3) { if ((numeroRect[0] == 1) && (numeroRect[1] == 4) && (numeroRect[2] == 2)) this.jTextField2.setText("Authenticated"); // Réinitilisation du compteur cptRect = 0; } } }
public Point findLaser(Mat inputFrame) { Mat mHsv = new Mat(); Imgproc.cvtColor(inputFrame, mHsv, Imgproc.COLOR_RGB2HSV); // Find laser center Mat center = new Mat(); Core.inRange(mHsv, new Scalar(0, 0, 250), new Scalar(180, 16, 255), center); Mat h = new Mat(); List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Imgproc.findContours(center, contours, h, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); center.release(); Mat center_mask = Mat.zeros(inputFrame.rows(), inputFrame.cols(), CvType.CV_8U); if (contours.size() > 0) { for (int i = 0; i < contours.size(); i++) { int radius = 10; // Point[] cont_pos = contours.get(i).toArray(); Moments m = Imgproc.moments(contours.get(i)); Point p = new Point(); p.x = m.get_m10() / m.get_m00(); p.y = m.get_m01() / m.get_m00(); Core.circle(center_mask, p, radius * 2, new Scalar(255), -1); } } // Find halo Mat ranged = new Mat(); Core.inRange(mHsv, new Scalar(100, 32, 225), new Scalar(150, 255, 255), ranged); mHsv.release(); // Mat f_frame =ranged.clone(); // Find halo around bright dot Core.bitwise_and(ranged, center_mask, ranged); center_mask.release(); // Find biggest resulting contour for (int i = 1; i < contours.size(); i++) { contours.get(i).release(); } contours.clear(); Imgproc.findContours(ranged, contours, h, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); h.release(); ranged.release(); if (contours.size() > 0) { MatOfPoint biggest_cont = contours.get(0); double cont_size = Imgproc.contourArea(biggest_cont); for (int i = 1; i < contours.size(); i++) { MatOfPoint cur = contours.get(i); if (Imgproc.contourArea(cur) > cont_size) { biggest_cont = cur; cont_size = Imgproc.contourArea(cur); } } Moments m = Imgproc.moments(biggest_cont); Point p = new Point(); p.x = m.get_m10() / m.get_m00(); p.y = m.get_m01() / m.get_m00(); for (int i = 1; i < contours.size(); i++) { contours.get(i).release(); } biggest_cont.release(); return p; } else { return null; } }
/** * Extracts and classifies colour bands for each Resistor. Each ColourBand object is instantiated * and linked to their parent Resistor object. * * @param resistorList A list of Resistor objects from which to extract the colour bands * @param paintDebugInfo If ture, the extracted colour band ROIs are displayed on the GUI */ private void extractColourBandsAndClassify(List<Resistor> resistorList, boolean paintDebugInfo) { if (resistorList.size() > 0) { for (int r = 0; r < resistorList.size(); r++) { Mat resImg = resistorList.get(r).resistorMat; Mat imgHSV = new Mat(); Mat satImg = new Mat(); Mat hueImg = new Mat(); // convert to HSV Imgproc.cvtColor(resImg, imgHSV, Imgproc.COLOR_BGR2HSV); ArrayList<Mat> channels = new ArrayList<Mat>(); Core.split(imgHSV, channels); // extract channels satImg = channels.get(1); // saturation hueImg = channels.get(0); // hue // threshold saturation channel Mat threshedROISatBands = new Mat(); // ~130 sat thresh val Imgproc.threshold(satImg, threshedROISatBands, SAT_BAND_THRESH, 255, Imgproc.THRESH_BINARY); // threshold hue channel Mat threshedROIHueBands = new Mat(); // ~50 hue thresh val Imgproc.threshold(hueImg, threshedROIHueBands, HUE_BAND_THRESH, 255, Imgproc.THRESH_BINARY); // combine the thresholded binary images Mat bandROI = new Mat(); Core.bitwise_or(threshedROIHueBands, threshedROISatBands, bandROI); // find contours in binary ROI image ArrayList<MatOfPoint> contours = new ArrayList<MatOfPoint>(); Mat hierarchy = new Mat(); Imgproc.findContours( bandROI, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE, new Point(0, 0)); // remove any remaining noise by only keeping contours which area > threshold for (int i = 0; i < contours.size(); i++) { double area = Imgproc.contourArea(contours.get(i)); if (area < MIN_BAND_AREA) { contours.remove(i); i--; } } // create a ColourBand object for each detected band // storing its center, the contour and the bandROI for (int i = 0; i < contours.size(); i++) { MatOfPoint contour = contours.get(i); // extract this colour band and store in a Mat Rect boundingRect = Imgproc.boundingRect(contour); Mat mask = Mat.zeros(bandROI.size(), CvType.CV_8U); Imgproc.drawContours(mask, contours, i, new Scalar(255), Core.FILLED); Mat imageROI = new Mat(); resImg.copyTo(imageROI, mask); Mat colourBandROI = new Mat(imageROI, boundingRect); // instantiate new ColourBand object ColourBand cb = new ColourBand(findCenter(contour), contour, colourBandROI); // cluster the band colour cb.clusterBandColour(BAND_COLOUR_K_MEANS); // classify using the Lab colourspace as feature vector Mat sampleMat = new Mat(1, 3, CvType.CV_32FC1); // create a Mat contacting the clustered band colour sampleMat.put(0, 0, cb.clusteredColourLAB[0]); sampleMat.put(0, 1, cb.clusteredColourLAB[1]); sampleMat.put(0, 2, cb.clusteredColourLAB[2]); Mat classifiedValue = new Mat(1, 1, CvType.CV_32FC1); Mat neighborResponses = new Mat(); // dont actually use this Mat dists = new Mat(); // dont actually use this // classify knn.find_nearest(sampleMat, 3, classifiedValue, neighborResponses, dists); // cast classified value into Colour enum and store cb.classifiedColour = ColourEnumVals[(int) classifiedValue.get(0, 0)[0]]; // add the band to the parent resistor resistorList.get(r).bands.add(cb); } // paint the extracted band ROIs if (paintDebugInfo) { Mat finalBandROIMask = Mat.zeros(bandROI.size(), CvType.CV_8U); for (int i = 0; i < contours.size(); i++) { Scalar color = new Scalar(255, 255, 255); Imgproc.drawContours( finalBandROIMask, contours, i, color, -1, 4, hierarchy, 0, new Point()); } Mat colourROI = new Mat(); resImg.copyTo(colourROI, finalBandROIMask); paintResistorSubRegion(colourROI, r); } } } }
public void run() { ArrayList<Geometry.Quad> squares; Mat image = new Mat(); Utils.bitmapToMat(source, image); Mat bwimage = new Mat(); cvtColor(image, bwimage, COLOR_RGB2GRAY); Mat blurred = new Mat(); medianBlur(image, blurred, 9); int width = blurred.width(); int height = blurred.height(); int depth = blurred.depth(); Mat gray0 = new Mat(width, height, depth); blurred.copyTo(gray0); squares = new ArrayList<Geometry.Quad>(); // find squares in every color plane of the image for (int c = 0; c < 3; c++) { Core.mixChannels( Arrays.asList(blurred), Arrays.asList(new Mat[] {gray0}), new MatOfInt(c, 0)); // try several threshold levels int thresholdLevel = 8; for (int l = 0; l < thresholdLevel; l++) { // use canny instead of 0 threshold level // canny helps catch squares with gradient shading Mat gray = new Mat(); if (l == 0) { Canny(gray0, gray, 10.0, 20.0, 3, false); Mat kernel = new Mat(11, 11, CvType.CV_8UC1, new Scalar(1)); dilate(gray, gray, kernel); } else { Mat thresh = new Mat(gray0.rows(), gray0.cols(), gray0.type()); threshold(gray0, thresh, ((double) l) / thresholdLevel * 255, 128, THRESH_BINARY_INV); cvtColor(thresh, gray, COLOR_BGR2GRAY); } // find contours and store them in a list List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); findContours(gray, contours, new Mat(), RETR_LIST, CHAIN_APPROX_SIMPLE); // test contours for (MatOfPoint contour : contours) { // approximate contour with accuracy proportional to the contour perimeter MatOfPoint2f thisContour = new MatOfPoint2f(contour.toArray()); double arclength = 0.02 * arcLength(thisContour, true); MatOfPoint2f approx = new MatOfPoint2f(); approxPolyDP(thisContour, approx, arclength, true); double area = contourArea(approx); boolean isConvex = isContourConvex(new MatOfPoint(approx.toArray())); if (approx.rows() == 4 && Math.abs(area) > SQUARE_SIZE && isConvex) { double maxCosine = 0; Point[] approxArray = approx.toArray(); for (int j = 2; j < 5; j++) { double cosine = Math.abs(angle(approxArray[j % 4], approxArray[j - 2], approxArray[j - 1])); maxCosine = Math.max(maxCosine, cosine); } if (maxCosine > THRESHOLD_COS) { squares.add(new Geometry.Quad(approxArray)); Log.d(TAG, "area = " + area); } } } } } result = new Bundle(); result.putParcelableArrayList("squares", squares); Log.d(TAG, "result created"); finish(); }