Example Fiducial Square Image

• 

  Rendered 3D flat squares on top of fiducials

Demonstration how to detect square image fiducials. After the fiducial detector has been created a description of each image it detects is passed in. These images are converted into binary images and resized if needed. A large number of unique fiducials can be detected with a linear growth in computational time.

Example Code:

• ExampleFiducialImage.java

Concepts:

• Fiducials
• Pose estimation

Relevant Examples/Tutorials:

• Tutorial Fiducials
• Example Fiducial Square Binary
• Example Fiducial Calibration Target

Relevant Applets:

• Applet Fiducials

Videos

• Fiducial Overview

Example Code

/**
 * Detects square binary fiducials inside an image, writes out there pose, and visualizes a virtual flat cube
 * above them in the input image.
 *
 * @author Peter Abeles
 */
public class ExampleFiducialImage {
	public static void main(String[] args) {

		String imagePath   = UtilIO.pathExample("fiducial/image/examples/");
		String patternPath = UtilIO.pathExample("fiducial/image/patterns/");

//		String imageName = "image00.jpg";
		String imageName = "image01.jpg";
//		String imageName = "image02.jpg";

		// load the lens distortion parameters and the input image
		IntrinsicParameters param = UtilIO.loadXML(imagePath, "intrinsic.xml");
		BufferedImage input = UtilImageIO.loadImage(imagePath, imageName);
		GrayF32 original = ConvertBufferedImage.convertFrom(input, true, ImageType.single(GrayF32.class));

		// Detect the fiducial
		SquareImage_to_FiducialDetector<GrayF32> detector = FactoryFiducial.squareImage(
				new ConfigFiducialImage(), ConfigThreshold.local(ThresholdType.LOCAL_SQUARE, 10), GrayF32.class);
//				new ConfigFiducialImage(), ConfigThreshold.fixed(100), GrayF32.class);

		// give it a description of all the targets
		double width = 4; // 4 cm
		detector.addPatternImage(loadImage(patternPath , "ke.png",          GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "dog.png",         GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "yu.png",          GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "yu_inverted.png", GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "pentarose.png",   GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "text_boofcv.png", GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "leaf01.png",      GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "leaf02.png",      GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "hand01.png",      GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "chicken.png",     GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "h2o.png",         GrayF32.class), 100, width);
		detector.addPatternImage(loadImage(patternPath , "yinyang.png",     GrayF32.class), 100, width);

		detector.setIntrinsic(param);

		detector.detect(original);

		// print the results
		Graphics2D g2 = input.createGraphics();
		Se3_F64 targetToSensor = new Se3_F64();
		for (int i = 0; i < detector.totalFound(); i++) {
			System.out.println("Target ID = "+detector.getId(i));
			detector.getFiducialToCamera(i, targetToSensor);
			System.out.println("Location:");
			System.out.println(targetToSensor);

			VisualizeFiducial.drawLabelCenter(targetToSensor, param, ""+detector.getId(i), g2);
			VisualizeFiducial.drawCube(targetToSensor,param,detector.getWidth(i), 3, g2);
		}

		ShowImages.showWindow(input,"Fiducials",true);
	}
}