Example Key Point Based Deformation

This example shows you key points can be used to deform an image. Here it is used to make it appear as if a wooden man is waving.

Example Code:

• ExamplePointDeformKeyPoints.java

Concepts:

• Image Deformation

Example Code

/**
 * Demonstration on how to use a key point based image deformation. A static image will be modified in real time
 * to make it appear as if the 'man' is waving. These deformation algorithms specify keypoints which match between
 * two images. When the pixel coordinate is moved the pixels are distorted such that they minimize an error function.
 *
 * @author Peter Abeles
 */
public class ExamplePointDeformKeyPoints {
	public static void main( String[] args ) {
		BufferedImage orig = UtilImageIO.loadImageNotNull(UtilIO.pathExample("standard/man_mls.jpg"));
		var bufferedOut = new BufferedImage(orig.getWidth(), orig.getHeight(), BufferedImage.TYPE_INT_RGB);

		Planar<GrayF32> input = ConvertBufferedImage.convertFrom(orig, true, ImageType.pl(3, GrayF32.class));
		Planar<GrayF32> output = input.createSameShape();

		var src = new ArrayList<Point2D_F32>();
		var dst = new ArrayList<Point2D_F32>();

		src.add(new Point2D_F32(64, 241));
		src.add(new Point2D_F32(266, 119));
		src.add(new Point2D_F32(265, 240));
		src.add(new Point2D_F32(208, 410));
		src.add(new Point2D_F32(181, 536));
		src.add(new Point2D_F32(335, 409));
		src.add(new Point2D_F32(375, 531));
		src.add(new Point2D_F32(473, 238));

		for (Point2D_F32 p : src) {
			dst.add(p.copy());
		}

		var config = new ConfigDeformPointMLS();
		PointDeformKeyPoints deform = FactoryDistort.deformMls(config);
		deform.setImageShape(input.width, input.height);


		ImageDistort<Planar<GrayF32>, Planar<GrayF32>> distorter =
				FactoryDistort.distort(true, InterpolationType.BILINEAR,
						BorderType.ZERO, input.getImageType(), input.getImageType());

		deform.setImageShape(input.width, input.height);
		deform.setSource(src);
		deform.setDestination(dst);

		ConvertBufferedImage.convertTo(output, bufferedOut, true);
		ImagePanel panel = ShowImages.showWindow(bufferedOut, "Point Based Distortion Animation", true);

		int count = 0;
		while (true) {
			// specify new locations of key points
			double theta = count++*Math.PI/30;
			dst.get(7).y = (float)(238 + Math.sin(theta)*30);       // right arm
			dst.get(0).y = (float)(241 - Math.sin(theta*2.0)*20);   // left arm
			dst.get(1).x = (float)(266 + Math.sin(theta*0.25)*10);  // head

			// tell the deformation algorithm that destination points have changed
			deform.setDestination(dst);
			// Tell the distorter that the model has changed. If cached is set to false you can ignore this step
			distorter.setModel(new PointToPixelTransform_F32(deform));
			// distort the image
			distorter.apply(input, output);
			// Show the results
			ConvertBufferedImage.convertTo(output, bufferedOut, true);
			panel.repaint();

			BoofMiscOps.sleep(30);
		}
	}
}