Merge pull request #77 from qwzybug/morphological-closing

Support for morphological operations like opening/closing et al.

Author: atduskgreg

examples/MorphologyOperations/MorphologyOperations.pde

@@ -0,0 +1,43 @@
+import gab.opencv.*;
+
+import org.opencv.imgproc.Imgproc;
+
+OpenCV opencv;
+PImage  img, opened, closed, tophat;
+
+void setup() {
+  img = loadImage("test.jpg");
+  size(img.width, img.height);
+
+  opencv = new OpenCV(this, img);
+  PImage snap = opencv.getSnapshot();
+ 
+  opencv.open(16);
+  opened = opencv.getSnapshot();
+  
+  opencv.loadImage(snap);
+  opencv.close(16);  
+  closed = opencv.getSnapshot();
+  
+  opencv.loadImage(snap);
+  opencv.morphX(Imgproc.MORPH_TOPHAT, Imgproc.MORPH_CROSS, 8, 8);
+  tophat = opencv.getSnapshot();
+}
+
+void draw() {
+  pushMatrix();
+  scale(0.5);
+  image(img, 0, 0);
+  image(opened, img.width, 0);
+  image(closed, 0, img.height);
+  image(tophat, img.width, img.height);
+  popMatrix();
+
+  fill(0);
+  text("source", img.width/2 - 100, 20 );
+  text("open(16)", img.width - 100, 20 );
+  text("close(16)", img.width/2 - 100, img.height/2 + 20 );
+  fill(255);
+  text("tophat(cross, 8, 8)", img.width - 150, img.height/2 + 20 );
+}
+

examples/MorphologyOperations/test.jpg

@@ -191,4 +191,10 @@ An in-depth advanced example. Detect a CV marker in an image, warp perspective,
 
 Code: [MarkerDetection.pde](https://github.com/atduskgreg/opencv-processing/blob/master/examples/MarkerDetection/MarkerDetection.pde)
 
+#### MorphologyOperations
 
+Open and close an image, or do more complicated morphological transformations.
+
+<a href="https://flic.kr/p/tazj7r" title="Morphology operations"><img src="https://farm6.staticflickr.com/5340/17829980821_1734e8bab8_z_d.jpg" width="640" height="393" alt="Morphology operations"></a>
+
+Code: [MorphologyOperations.pde](examples/MorphologyOperations/MorphologyOperations.pde)

readme.md

@@ -927,6 +927,55 @@ public void erode(){
 		Imgproc.erode(getCurrentMat(), getCurrentMat(), new Mat());
 	}
 
+  /**
+   * Apply a morphological operation (e.g., opening, closing) to the image with a given kernel element.
+   *
+   * See:
+   * http://docs.opencv.org/doc/tutorials/imgproc/opening_closing_hats/opening_closing_hats.html
+   * 
+   * @param operation
+   *    The morphological operation to apply: Imgproc.MORPH_CLOSE, MORPH_OPEN,
+   *    MORPH_TOPHAT, MORPH_BLACKHAT, MORPH_GRADIENT.
+   * @param kernelElement
+   *    The shape to apply the operation with: Imgproc.MORPH_RECT, MORPH_CROSS, or MORPH_ELLIPSE.
+   * @param width
+   *    Width of the shape.
+   * @param height
+   *    Height of the shape.
+   */
+  public void morphX(int operation, int kernelElement, int width, int height) {
+    Mat kernel = Imgproc.getStructuringElement(kernelElement, new Size(width, height));
+    Imgproc.morphologyEx(getCurrentMat(), getCurrentMat(), operation, kernel);
+  }
+  
+  /**
+   * Close the image with a circle of a given size.
+   *
+   * See:
+   * http://docs.opencv.org/doc/tutorials/imgproc/opening_closing_hats/opening_closing_hats.html#closing
+   *
+   * @param size
+   *    Radius of the circle to close with.
+   */
+  public void close(int size) {
+    Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(size, size));
+    Imgproc.morphologyEx(getCurrentMat(), getCurrentMat(), Imgproc.MORPH_CLOSE, kernel);
+  }
+	
+  /**
+   * Open the image with a circle of a given size.
+   *
+   * See:
+   * http://docs.opencv.org/doc/tutorials/imgproc/opening_closing_hats/opening_closing_hats.html#opening
+   *
+   * @param size
+   *    Radius of the circle to open with.
+   */
+  public void open(int size) {
+    Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, new Size(size, size));
+    Imgproc.morphologyEx(getCurrentMat(), getCurrentMat(), Imgproc.MORPH_OPEN, kernel);
+  }
+  
 	/**
 	 * Blur an image symetrically by a given number of pixels.
 	 *