Java Code Examples for org.opencv.imgproc.Imgproc#contourArea()
The following examples show how to use
org.opencv.imgproc.Imgproc#contourArea() .
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Example 1
| Source File: VideoMotionDetector.java From video-stream-analytics with Apache License 2.0 | 6 votes |
|
private static ArrayList<Rect> getContourArea(Mat mat) {
Mat hierarchy = new Mat();
Mat image = mat.clone();
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Imgproc.findContours(image, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
Rect rect = null;
double maxArea = 300;
ArrayList<Rect> arr = new ArrayList<Rect>();
for (int i = 0; i < contours.size(); i++) {
Mat contour = contours.get(i);
double contourArea = Imgproc.contourArea(contour);
if (contourArea > maxArea) {
rect = Imgproc.boundingRect(contours.get(i));
arr.add(rect);
}
}
return arr;
}
Example 2
| Source File: MainActivity.java From SimpleDocumentScanner-Android with MIT License | 6 votes |
|
/**
* Find the largest 4 point contour in the given Mat.
*
* @param src A valid Mat
* @return The largest contour as a Mat
*/
private MatOfPoint2f findLargestContour(Mat src) {
List<MatOfPoint> contours = new ArrayList<>();
Imgproc.findContours(src, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
// Get the 5 largest contours
Collections.sort(contours, new Comparator<MatOfPoint>() {
public int compare(MatOfPoint o1, MatOfPoint o2) {
double area1 = Imgproc.contourArea(o1);
double area2 = Imgproc.contourArea(o2);
return (int) (area2 - area1);
}
});
if (contours.size() > 5) contours.subList(4, contours.size() - 1).clear();
MatOfPoint2f largest = null;
for (MatOfPoint contour : contours) {
MatOfPoint2f approx = new MatOfPoint2f();
MatOfPoint2f c = new MatOfPoint2f();
contour.convertTo(c, CvType.CV_32FC2);
Imgproc.approxPolyDP(c, approx, Imgproc.arcLength(c, true) * 0.02, true);
if (approx.total() == 4 && Imgproc.contourArea(contour) > 150) {
// the contour has 4 points, it's valid
largest = approx;
break;
}
}
return largest;
}
Example 3
| Source File: MaxAreaScorer.java From DogeCV with GNU General Public License v3.0 | 5 votes |
|
/**
* Calculate the score
* @param input - Input mat (Can be MatOfPoint for contours)
* @return - Difference from perfect score
*/
@Override
public double calculateScore(Mat input) {
if(!(input instanceof MatOfPoint)) return Double.MAX_VALUE;
MatOfPoint contour = (MatOfPoint) input;
double area = Imgproc.contourArea(contour);
return -area * weight;
}
Example 4
| Source File: PerfectAreaScorer.java From DogeCV with GNU General Public License v3.0 | 5 votes |
|
/**
* @param input - Input mat (Can be MatOfPoint for contours)
* @return - Difference from perfect score
*/
@Override
public double calculateScore(Mat input) {
if(!(input instanceof MatOfPoint)) return Double.MAX_VALUE;
MatOfPoint contour = (MatOfPoint) input;
double area = Imgproc.contourArea(contour);
double areaDiffrence = Math.abs(perfectArea - area);
return areaDiffrence * weight;
}
Example 5
| Source File: ColorBlobDetector.java From FaceT with Mozilla Public License 2.0 | 5 votes |
|
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);
}
}
}
Example 6
| Source File: ContoursFinder.java From go-bees with GNU General Public License v3.0 | 5 votes |
|
@Override
public Mat process(@NonNull Mat frame) {
if (frame.empty()) {
Log.e("Invalid input frame.");
return null;
}
Mat tmp = frame.clone();
// Finding outer contours
contourList.clear();
Imgproc.findContours(tmp, contourList, hierarchy,
Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
// Filter bees
Mat contours = new Mat(tmp.rows(), tmp.cols(), CvType.CV_8UC3);
tmp.release();
double area;
Scalar color;
numBees = 0;
for (int i = 0; i < contourList.size(); i++) {
area = Imgproc.contourArea(contourList.get(i));
if (area > minArea && area < maxArea) {
color = GREEN;
numBees++;
} else {
color = RED;
}
// Draw contour
Imgproc.drawContours(contours, contourList, i, color, -1);
}
return contours;
}
Example 7
| Source File: ColorBlobDetector.java From OpenCV-AndroidSamples with MIT License | 5 votes |
|
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);
}
}
}
Example 8
| Source File: ColorBlobDetector.java From hand_finger_recognition_android with MIT License | 5 votes |
|
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);
}
}
}
Example 9
| Source File: NativeClass.java From AndroidDocumentScanner with MIT License | 4 votes |
|
public int compare(MatOfPoint2f m1, MatOfPoint2f m2) {
double area1 = Imgproc.contourArea(m1);
double area2 = Imgproc.contourArea(m2);
return (int) Math.ceil(area2 - area1);
}
Example 10
| Source File: Proc.java From android-object-distance with Apache License 2.0 | 4 votes |
|
public static double findMarkerWidth(String imgPath){
Mat frame = Highgui.imread(imgPath);
Mat gscale = new Mat();
Mat blur = new Mat();
Mat edged = new Mat();
// convert the image to grayscale, blur it, and detect edges
if(frame.channels()>1)
Imgproc.cvtColor(frame, gscale, Imgproc.COLOR_BGR2GRAY);
else
gscale = frame;
Imgproc.GaussianBlur(gscale, blur, new Size(5, 5), 0);
Imgproc.Canny(blur, edged, 35, 125);
// find the contours in the edged image and keep the largest one;
// we'll assume that this is our piece of paper in the image
List<MatOfPoint> contours = new ArrayList<>();
Mat hierarchy = new Mat(edged.width(), edged.height(), CvType.CV_8UC1);
Imgproc.findContours(edged.clone(), contours, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
int max_idx = 0;
// if any contour exist...
if (hierarchy.size().height > 0 && hierarchy.size().width > 0)
{
double max_area = 0;
double area;
// find the contour with largest area
for (int idx = 0; idx >= 0; idx = (int) hierarchy.get(0, idx)[0])
{
area = Imgproc.contourArea(contours.get(idx));
if(area > max_area){
max_area = area;
max_idx = idx;
}
Imgproc.drawContours(frame, contours, idx, new Scalar(0, 0, 255));
}
//Riz: Save File
//Imgproc.drawContours(frame, contours, max_idx, new Scalar(250, 0, 0));
byte[] bytes = new byte[ frame.rows() * frame.cols() * frame.channels() ];
File file = new File(CameraActivity.activity.getExternalFilesDir(null), "pic_contour"+ Integer.toString(pic_count) + ".jpg");
pic_count++;
Boolean bool = null;
String filename = file.toString();
bool = Highgui.imwrite(filename, frame);
if (bool == true)
Log.d(LOG_TAG, "SUCCESS writing image to external storage");
else
Log.d(LOG_TAG, "Fail writing image to external storage");
Log.i(LOG_TAG, "Max Area: " + Double.toString(max_area));
}
else{
Log.e(LOG_TAG, "No Contour Found!");
}
MatOfPoint2f newPoint = new MatOfPoint2f(contours.get(max_idx).toArray());
return Imgproc.arcLength(newPoint, true);
}
Example 11
| Source File: ResistorImageProcessor.java From ResistorScanner with MIT License | 4 votes |
|
private void findLocations(Mat searchMat)
{
_locationValues.clear();
SparseIntArray areas = new SparseIntArray(4);
for(int i = 0; i < NUM_CODES; i++)
{
Mat mask = new Mat();
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Mat hierarchy = new Mat();
if(i == 2)
{
// combine the two ranges for red
Core.inRange(searchMat, LOWER_RED1, UPPER_RED1, mask);
Mat rmask2 = new Mat();
Core.inRange(searchMat, LOWER_RED2, UPPER_RED2, rmask2);
Core.bitwise_or(mask, rmask2, mask);
}
else
Core.inRange(searchMat, COLOR_BOUNDS[i][0], COLOR_BOUNDS[i][1], mask);
Imgproc.findContours(mask, contours, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
for (int contIdx = 0; contIdx < contours.size(); contIdx++)
{
int area;
if ((area = (int)Imgproc.contourArea(contours.get(contIdx))) > 20)
{
Moments M = Imgproc.moments(contours.get(contIdx));
int cx = (int) (M.get_m10() / M.get_m00());
// if a colour band is split into multiple contours
// we take the largest and consider only its centroid
boolean shouldStoreLocation = true;
for(int locIdx = 0; locIdx < _locationValues.size(); locIdx++)
{
if(Math.abs(_locationValues.keyAt(locIdx) - cx) < 10)
{
if (areas.get(_locationValues.keyAt(locIdx)) > area)
{
shouldStoreLocation = false;
break;
}
else
{
_locationValues.delete(_locationValues.keyAt(locIdx));
areas.delete(_locationValues.keyAt(locIdx));
}
}
}
if(shouldStoreLocation)
{
areas.put(cx, area);
_locationValues.put(cx, i);
}
}
}
}
}
Example 12
| Source File: AAVActivity.java From AAV with GNU General Public License v2.0 | 4 votes |
|
@Override
public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
synchronized (inputFrame) {
_rgbaImage = inputFrame.rgba();
if (android.os.Build.MODEL.equalsIgnoreCase("Nexus 5X")) {
Core.flip(_rgbaImage, _rgbaImage, -1);
}
double current_contour;
// In contrast to the C++ interface, Android API captures images in the RGBA format.
// Also, in HSV space, only the hue determines which color it is. Saturation determines
// how 'white' the color is, and Value determines how 'dark' the color is.
Imgproc.cvtColor(_rgbaImage, _hsvMat, Imgproc.COLOR_RGB2HSV_FULL);
Core.inRange(_hsvMat, _lowerThreshold, _upperThreshold, _processedMat);
// Imgproc.dilate(_processedMat, _dilatedMat, new Mat());
Imgproc.erode(_processedMat, _dilatedMat, new Mat());
Imgproc.findContours(_dilatedMat, contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
MatOfPoint2f points = new MatOfPoint2f();
_contourArea = 7;
for (int i = 0, n = contours.size(); i < n; i++) {
current_contour = Imgproc.contourArea(contours.get(i));
if (current_contour > _contourArea) {
_contourArea = current_contour;
contours.get(i).convertTo(points, CvType.CV_32FC2); // contours.get(x) is a single MatOfPoint, but to use minEnclosingCircle we need to pass a MatOfPoint2f so we need to do a
// conversion
}
}
if (!points.empty() && _contourArea > MIN_CONTOUR_AREA) {
Imgproc.minEnclosingCircle(points, _centerPoint, null);
// Core.circle(_rgbaImage, _centerPoint, 3, new Scalar(255, 0, 0), Core.FILLED);
if (_showContourEnable)
Core.circle(_rgbaImage, _centerPoint, (int) Math.round(Math.sqrt(_contourArea / Math.PI)), new Scalar(255, 0, 0), 3, 8, 0);// Core.FILLED);
}
contours.clear();
}
return _rgbaImage;
}
Example 13
| Source File: CropImage.java From reader with MIT License | 4 votes |
|
private void makeDefault() {
HighlightView hv = new HighlightView(mImageView);
int width = mBitmap.getWidth();
int height = mBitmap.getHeight();
Rect imageRect = new Rect(0, 0, width, height);
// make the default size about 4/5 of the width or height
// int cropWidth = Math.min(width, height) * 4 / 5;
// int cropHeight = cropWidth;
int cropWidth = width;
int cropHeight = height;
if (mAspectX != 0 && mAspectY != 0) {
if (mAspectX > mAspectY) {
// �����辩缉���
cropHeight = cropWidth * mAspectY ;// mAspectX;
} else {
cropWidth = cropHeight * mAspectX ;// mAspectY;
}
}
int x = (width - cropWidth) / 2;
int y = (height - cropHeight) / 2;
Mat imgSource = new Mat();
Utils.bitmapToMat(mBitmap, imgSource);
//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 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;
float x1, y1, x2, y2;
temp_double = approxCurve.get(0,0);
Point p1 = new Point(temp_double[0], temp_double[1]);
x1 = (float)temp_double[0];
y1 = (float)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]);
x2 = (float)temp_double[0];
y2 = (float)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]);
RectF cropRect = new RectF(x, y, x + cropWidth, y + cropHeight);
//RectF cropRect = new RectF(x1, y1, x2, y2);
// �����辩缉���
hv.setup(mImageMatrix, imageRect, cropRect, mCircleCrop,false
/*mAspectX != 0 && mAspectY != 0*/);
mImageView.add(hv);
}
Example 14
| Source File: BallDetector.java From opencv-fun with GNU Affero General Public License v3.0 | 4 votes |
|
private void extractCircles (Mat mask, List<Circle> balls, List<BallCluster> ballClusters, List<MatOfPoint> contours) {
// clear input
balls.clear();
ballClusters.clear();
contours.clear();
// find the contours
Imgproc.findContours(mask.clone(), contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
// iterate through the contours, find single balls and clusters of balls touching each other
double minArea = Math.PI * (calib.getBallRadius() * 0.9f) * (calib.getBallRadius() * 0.9f); // minimal ball area
double maxArea = Math.PI * (calib.getBallRadius() * 1.1f) * (calib.getBallRadius() * 1.1f); // maximal ball area
for (int i = 0; i < contours.size(); i++) {
double area = Imgproc.contourArea(contours.get(i));
if (area > minArea) {
if (area < maxArea) {
// we found a ball
float[] radius = new float[1];
Point center = new Point();
Imgproc.minEnclosingCircle(new MatOfPoint2f(contours.get(i).toArray()), center, radius);
balls.add(new Circle(center.x, center.y, calib.getBallRadius()));
} else {
// we found a cluster of balls
int numBalls = (int)(area / (Math.PI * calib.getBallRadius() * calib.getBallRadius() * 0.9));
// draw the contours to a bit mask
Mat hough = Mat.zeros(mask.size(), CvType.CV_8U);
Imgproc.drawContours(hough, contours, i, new Scalar(255, 255, 255), -2);
// detect hough circles, try different params until we hit the number of balls
Mat houghCircles = new Mat();
int hit = 0;
for(int j = 8; j < 20; j++) {
Imgproc.HoughCircles(hough, houghCircles, Imgproc.CV_HOUGH_GRADIENT, 2, calib.getBallRadius() * 0.9 * 2, 255, j, (int)(calib.getBallRadius() * 0.9), (int)(calib.getBallRadius() * 1.1));
if(houghCircles.cols() <= numBalls) {
hit++;
if(hit == 4) break;
}
}
List<Circle> estimatedCircles = new ArrayList<Circle>();
for(int j = 0; j < houghCircles.cols(); j++) {
double[] circle = houghCircles.get(0, j);
if(circle != null) {
estimatedCircles.add(new Circle(circle[0], circle[1], calib.getBallRadius()));
}
}
ballClusters.add(new BallCluster(contours.get(i), numBalls, estimatedCircles));
}
}
}
}
Example 15
| Source File: Contour.java From FTCVision with MIT License | 2 votes |
|
/**
* Get the area of the contour
* <p/>
* A highly precise method that integrates the contour with respect to its arc length.
*
* @return Area of the contour
*/
public double area() {
return Imgproc.contourArea(mat);
}
