Example Detect Black Ellipses - Revision history

Peter at 20:55, 17 January 2022

2022-01-17T20:55:28Z

← Older revision		Revision as of 20:55, 17 January 2022
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	Example Code:		Example Code:
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.40/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

	Concepts:		Concepts:
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	for (String fileName : images) {		for (String fileName : images) {
	BufferedImage image = UtilImageIO.~~loadImage~~(UtilIO.pathExample(fileName));		BufferedImage image = UtilImageIO.loadImageNotNull(UtilIO.pathExample(fileName));

	GrayU8 input = ConvertBufferedImage.convertFromSingle(image, null, GrayU8.class);		GrayU8 input = ConvertBufferedImage.convertFromSingle(image, null, GrayU8.class);

Peter at 17:41, 12 July 2021

2021-07-12T17:41:55Z

← Older revision		Revision as of 17:41, 12 July 2021
Line 5:		Line 5:

	Example Code:		Example Code:
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.37/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

	Concepts:		Concepts:
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	<syntaxhighlight lang="java">		<syntaxhighlight lang="java">
	/**		/**
	* Example of how to detect black ellipses with a white background inside of images. These ellipses will have a		* Example of how to detect black ellipses with a white background inside of images. These ellipses will have a
	* high level of accuracy and are used in camera calibration else where.		* high level of accuracy and are used in camera calibration else where.
	*		*
Line 28:		Line 28:
	*/		*/
	public class ExampleDetectBlackEllipse {		public class ExampleDetectBlackEllipse {
	public static void main(String[] args) {		public static void main( String[] args ) {
	String[] images = new String[]{		String[] images = new String[]{
	"shapes/polygons01.jpg",		"shapes/polygons01.jpg",
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	BinaryEllipseDetector<GrayU8> detector = FactoryShapeDetector.ellipse(null, GrayU8.class);		BinaryEllipseDetector<GrayU8> detector = FactoryShapeDetector.ellipse(null, GrayU8.class);

	for( String fileName : images ) {		for (String fileName : images) {
	BufferedImage image = UtilImageIO.loadImage(UtilIO.pathExample(fileName));		BufferedImage image = UtilImageIO.loadImage(UtilIO.pathExample(fileName));

	GrayU8 input = ConvertBufferedImage.convertFromSingle(image, null, GrayU8.class);		GrayU8 input = ConvertBufferedImage.convertFromSingle(image, null, GrayU8.class);
	GrayU8 binary = new GrayU8(input.width,input.height);		GrayU8 binary = new GrayU8(input.width, input.height);

	// Binarization is done outside to allows creative tricks. For example, when applied to a chessboard		// Binarization is done outside to allows creative tricks. For example, when applied to a chessboard
	// pattern where square touch each other, the binary image is eroded first so that they don't touch.		// pattern where square touch each other, the binary image is eroded first so that they don't touch.
	// The squares are expanded automatically during the subpixel optimization step.		// The squares are expanded automatically during the subpixel optimization step.
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	DogArray<BinaryEllipseDetector.EllipseInfo> found = detector.getFound();		DogArray<BinaryEllipseDetector.EllipseInfo> found = detector.getFound();
	Graphics2D g2 = image.createGraphics();		Graphics2D g2 = image.createGraphics();
	g2.setStroke(new BasicStroke(3));		g2.setStroke(new BasicStroke(5));
	g2.setColor(Color.RED);		g2.setColor(Color.RED);
	for (int i = 0; i < found.size; i++) {		for (int i = 0; i < found.size; i++) {
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	}		}

	panel.addImage(image,new File(fileName).getName());		panel.addImage(image, new File(fileName).getName());
	}		}

	ShowImages.showWindow(panel,"Detected Ellipses",true);		ShowImages.showWindow(panel, "Detected Ellipses", true);
	}		}
	}		}
	</syntaxhighlight>		</syntaxhighlight>

Peter at 20:00, 21 December 2020

2020-12-21T20:00:35Z

← Older revision		Revision as of 20:00, 21 December 2020
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	Example Code:		Example Code:
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.29/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.37/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

	Concepts:		Concepts:
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	public class ExampleDetectBlackEllipse {		public class ExampleDetectBlackEllipse {
	public static void main(String[] args) {		public static void main(String[] args) {
	String ~~images~~[] = new String[]{		String[] images = new String[]{
	"shapes/polygons01.jpg",		"shapes/polygons01.jpg",
	"shapes/shapes02.png",		"shapes/shapes02.png",
Line 57:		Line 57:

	// visualize results by drawing red polygons		// visualize results by drawing red polygons
	~~FastQueue~~<BinaryEllipseDetector.EllipseInfo> found = detector.getFound();		DogArray<BinaryEllipseDetector.EllipseInfo> found = detector.getFound();
	Graphics2D g2 = image.createGraphics();		Graphics2D g2 = image.createGraphics();
	g2.setStroke(new BasicStroke(3));		g2.setStroke(new BasicStroke(3));

Peter at 02:57, 19 March 2018

2018-03-19T02:57:27Z

← Older revision		Revision as of 02:57, 19 March 2018
Line 5:		Line 5:

	Example Code:		Example Code:
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.28/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.29/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

	Concepts:		Concepts:
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	// pattern where square touch each other, the binary image is eroded first so that they don't touch.		// pattern where square touch each other, the binary image is eroded first so that they don't touch.
	// The squares are expanded automatically during the subpixel optimization step.		// The squares are expanded automatically during the subpixel optimization step.
	int threshold = GThresholdImageOps.computeOtsu(input, 0, 255);		int threshold = (int)GThresholdImageOps.computeOtsu(input, 0, 255);
	ThresholdImageOps.threshold(input, binary, threshold, true);		ThresholdImageOps.threshold(input, binary, threshold, true);

Peter at 05:38, 20 January 2018

2018-01-20T05:38:22Z

← Older revision		Revision as of 05:38, 20 January 2018
Line 5:		Line 5:

	Example Code:		Example Code:
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.25/examples/src/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.28/examples/src/main/java/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

	Concepts:		Concepts:
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	"shapes/polygons01.jpg",		"shapes/polygons01.jpg",
	"shapes/shapes02.png",		"shapes/shapes02.png",
	"fiducial/~~circle_asymmetric~~/image00.jpg",		"fiducial/circle_hexagonal/image00.jpg",
	"fiducial/~~circle_asymmetric~~/image01.jpg"};		"fiducial/circle_hexagonal/image01.jpg"};

	ListDisplayPanel panel = new ListDisplayPanel();		ListDisplayPanel panel = new ListDisplayPanel();
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	// visualize results by drawing red polygons		// visualize results by drawing red polygons
	FastQueue<~~EllipseRotated_F64~~> found = detector.~~getFoundEllipses~~();		FastQueue<BinaryEllipseDetector.EllipseInfo> found = detector.getFound();
	Graphics2D g2 = image.createGraphics();		Graphics2D g2 = image.createGraphics();
	g2.setStroke(new BasicStroke(3));		g2.setStroke(new BasicStroke(3));
	g2.setColor(Color.RED);		g2.setColor(Color.RED);
	for (int i = 0; i < found.size; i++) {		for (int i = 0; i < found.size; i++) {
	VisualizeShapes.drawEllipse(found.get(i), g2);		VisualizeShapes.drawEllipse(found.get(i).ellipse, g2);
	}		}

Peter at 18:00, 5 January 2017

2017-01-05T18:00:13Z

← Older revision		Revision as of 18:00, 5 January 2017
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	* Fiducials		* Fiducials

	Related Examples		Related Examples:
	* [[Example_Detect_Black_Polygons\|Black Polygons]]		* [[Example_Detect_Black_Polygons\|Black Polygons]]
	* [[Example_Detect_Calibration_Target\| Calibration Target]]		* [[Example_Detect_Calibration_Target\| Calibration Target]]

			Videos:
			* [https://youtu.be/qMTtdiujAtQ?t=513 Ellipse Detector]

	= Example Code =		= Example Code =

Peter at 05:28, 2 December 2016

2016-12-02T05:28:06Z

← Older revision		Revision as of 05:28, 2 December 2016
Line 12:		Line 12:

	Related Examples		Related Examples
			* [[Example_Detect_Black_Polygons\|Black Polygons]]
	* [[Example_Detect_Calibration_Target\| Calibration Target]]		* [[Example_Detect_Calibration_Target\| Calibration Target]]

Peter: Created page with " Red lines outline detected ellipses BinaryEllipseDetector will detect ellipses inside an image which are black to a high level o..."

2016-12-01T22:38:04Z

Created page with " center|border|Red lines outline detected ellipses BinaryEllipseDetector will detect ellipses inside an image which are black to a high level o..."

New page

[[File:Detected_ellipses.jpg|center|border|Red lines outline detected ellipses]]

BinaryEllipseDetector will detect ellipses inside an image which are black to a high level of precision quickly. Detection is done inside a binary image with subpixel refinement inside a gray scale image. These ellipses are used by ellipses based calibration targets

Example Code:
* [https://github.com/lessthanoptimal/BoofCV/blob/v0.25/examples/src/boofcv/examples/features/ExampleDetectBlackEllipse.java ExampleDetectBlackEllipse.java]

Concepts:
* Ellipses
* Fiducials

Related Examples
* [[Example_Detect_Calibration_Target| Calibration Target]]

= Example Code =

<syntaxhighlight lang="java">
/**
* Example of how to detect black ellipses with a white background inside of images. These ellipses will have a
* high level of accuracy and are used in camera calibration else where.
*
* @author Peter Abeles
*/
public class ExampleDetectBlackEllipse {
public static void main(String[] args) {
String images[] = new String[]{
"shapes/polygons01.jpg",
"shapes/shapes02.png",
"fiducial/circle_asymmetric/image00.jpg",
"fiducial/circle_asymmetric/image01.jpg"};

ListDisplayPanel panel = new ListDisplayPanel();

BinaryEllipseDetector<GrayU8> detector = FactoryShapeDetector.ellipse(null, GrayU8.class);

for( String fileName : images ) {
BufferedImage image = UtilImageIO.loadImage(UtilIO.pathExample(fileName));

GrayU8 input = ConvertBufferedImage.convertFromSingle(image, null, GrayU8.class);
GrayU8 binary = new GrayU8(input.width,input.height);

// Binarization is done outside to allows creative tricks. For example, when applied to a chessboard
// pattern where square touch each other, the binary image is eroded first so that they don't touch.
// The squares are expanded automatically during the subpixel optimization step.
int threshold = GThresholdImageOps.computeOtsu(input, 0, 255);
ThresholdImageOps.threshold(input, binary, threshold, true);

// it takes in a grey scale image and binary image
// the binary image is used to do a crude polygon fit, then the grey image is used to refine the lines
// using a sub-pixel algorithm
detector.process(input, binary);

// visualize results by drawing red polygons
FastQueue<EllipseRotated_F64> found = detector.getFoundEllipses();
Graphics2D g2 = image.createGraphics();
g2.setStroke(new BasicStroke(3));
g2.setColor(Color.RED);
for (int i = 0; i < found.size; i++) {
VisualizeShapes.drawEllipse(found.get(i), g2);
}

panel.addImage(image,new File(fileName).getName());
}

ShowImages.showWindow(panel,"Detected Ellipses",true);
}
}
</syntaxhighlight>