• Easy to install. No dependencies.
• Image-based = awesome! Way more practical & versatile.
• Plenty of clear examples to get you started.
• Easy syntax. It just makes sense.
• Fresh as fruit! Unlike several severely outdated alternatives.

• I suggest placing the jar in a library folder besides the other main folders like examples, javadocs etc.
• No need to place each of the examples in a second subdirectory.
• Number the examples (01, 02, 03 etc.) so they are sorted correctly in Processing.
• Typo in example 06_drawContours. Last line should be: "bd.drawContours(contoursBoxCol, contoursThickness);"
• Example 15 is empy.
• Example 14 and 18 are basically identical.
• Nearly all the examples are image-based, which is great. Keep doing this! In fact, the few remaining capture-based examples (like 22_isBlob) could perhaps also be rewritten as image-based examples.

• There are 17 blobs in the image.
• The mass of blob #2 is 102738 pixels.
• The height of blob #2 is 464 pixels.
• The width of blob #2 is 580 pixels.
• The center of blob #2 is 332,267 (blue circle)
• The center of blob #2's bounding box is 297,245 (green circle)

• I wanna get the edge coordinates of the biggest blob in the image (aka me) and I'm assuming the getEdge functions will come in handy for this. If you could say or show how those functions work that would be great. Ideally I'd like to get an array of coordinates that is logically sorted. By which I mean that subsequent coordinates are like the path following the edge. Is this possible?
• On a side note, although I might not be needing this if the edge coordinates array works out, but is it possible to draw the contours to a PGraphic?
• Finally, would implementing isBlob for a specific blob be possible? => boolean isBlob(int x, int y, int blobnumber)
  

1. // A variable threshold filter class
2. // Antonio Molinaro 27/02/2011
3. VariableThreshold vt;
4. PImage source; 
5. PImage destination;
6. float threshold;
7. void setup() {
8.  
9. size(200,200);
10. source = loadImage( "image.jpg" );
11. vt = new VariableThreshold();
12.  
13. }
14. void draw() {
15.   
16.   image(vt.getImage(source),0,0);
17.  
18. }
19. void mouseDragged(){
20.   vt.setThreshold((float)mouseX,0.0,200.0,0.0,255.0);
21.   println(vt.getThreshold());
22. }
23. void mousePressed(){
24.   vt.setThreshold(random(255));
25.   println(vt.getThreshold());
26. }
27. //==========================
28. // variable threshold class
29. // @autor Antonio Molinaro
30. // @date 13/09/2009
31. //==========================
32. class VariableThreshold {
33.   PImage dst;
34.   float threshold;
35.  
36.  
37.   public VariableThreshold(){}
38.  
39.  
40.   /**
41.    * Sets a fixed threshold value
42.    * @param T thre threshold to apply
43.    */ 
44.   public void setThreshold(float T){
45.     threshold = T;
46.   }
47.   /**
48.    * Sets a variable threshold value
49.    * @param  controlValue    The control variable value
50.    * @param  controlValueMin The control variable max value
51.    * @param  controlValueMax The control variable min value
52.    * @param  from_T          The Threshold min value
53.    * @param  to_T            The threshold max value
54.    */ 
55.   public void setThreshold(float controlValue,
56.                      float controlValueMin,
57.                      float controlValueMax,
58.                      float from_T,
59.                      float to_T){
60.                       
61.     threshold = map(controlValue,controlValueMin, controlValueMax,  from_T,  to_T);
62.    
63.   }
64.   /**
65.    * Applies the variable threshold filter
66.    * to the src PImage parameter
67.    * @param src Thre PImage to filter
68.    * @return a  PImage object
69.    * representing the filtered PImage passed
70.    * as argument to the mothod
    
71.    */ 
72.  
73.   public PImage getImage(PImage src){
74.    
75.     dst = createImage(src.width, src.height, 12);  
76.     src.loadPixels();
77.     dst.loadPixels();
78.       for (int x = 0; x < src.width; x++ ) {
79.         for (int y = 0; y < src.height; y++ ) {
80.          int loc = x + y * src.width;
81.         if (brightness(src.pixels[loc]) > threshold){
82.         dst.pixels[loc] = color(255); 
83.         } else {
84.         dst.pixels[loc] = color(0); 
85.         }
86.        
87.         }
88.         }
89.        
90.         dst.updatePixels();
91.  
92.       return dst;
93.       }
94.   /**
95.    * Returns the threshold value used by the filter
96.    */     
97.   public float getThreshold(){
98.     return threshold;
99.   }
100.      
101. }

hand gesture recognition & virtual slider with Processing from robdanet on Vimeo.

1. import processing.video.*;
2. import Blobscanner.*;
3. Capture video;
4. Detector bd;
5. int w = 320;
6. int h = 240;
7. float thres =0.5;
8. PImage blobImage;
9. PImage bgImage;
10. PImage finalImage;
11. void setup(){  
12. size(w, h);  
13. video = new Capture(this, w, h, 30);  
14. bd = new Detector( this, 0, 0, video.width, video.height, 255);   
15. blobImage = createImage(video.width,video.height, GRAY);//if you dont need the alpha channel
16. bgImage = createImage(video.width,video.height,ARGB);   //use GRAY, it speeds a lot  
17. finalImage = createImage(video.width,video.height, RGB);
18. }
19. void draw(){     
20. if(video.available()) {    
21. video.read();  
22. }
23.  
24. arrayCopy(video.pixels,finalImage.pixels);//save a frame before processing
25. //image(video, 0, 0);//this doesn't go here
26.  
27.  
28. video.filter(GRAY);
29. //video.loadPixels();  
30. //bgImage.loadPixels();
31. blobImage.loadPixels();
32. video.filter(BLUR,2);             //too many blobs, you need  blur the image
33. video.filter(THRESHOLD, thres);
34. video.loadPixels();               //load after the filter have been applied
35. bd.findBlobs(video.pixels, video.width, video.height);
36.  
37. //This call is indispensable for nearly all the other methods  
38. //(please check javadoc).  
39. bd.loadBlobsFeatures();    
40. //This methods needs to be called before to call   
41. //findCentroids(booleaan, boolean) methods.  
42. bd.weightBlobs(true);   
43. //Computes the blob center of mass. If the first argument is true,   
44. //prints the center of mass coordinates x y to the console. If the   
45. //second argument is true, draws a point at the center of mass coordinates.  
46. //bd.findCentroids(false, false);    
47.  
48. for(int x = 0; x < video.width; x++){    
49.   for(int y = 0; y < video.height; y++){            
50.     int loc = x+y*video.width;            
51.     if(bd.isBlob(x, y) ){       
52.       blobImage.pixels[loc] = finalImage.pixels[loc];
53.     } else {       
54.       blobImage.pixels[loc] = color(0);      
55.       }         
56.     }  
57.   }
58.   blobImage.updatePixels();
59.  
60.   image(blobImage, 0, 0);
61.   if(bd.getBlobsNumber() > 0)
62.   println("some other text....Hi! "+frameCount+ " I'm working!");
63.  
64.  
65. //bd.drawSelectBox(200,color(0,255, 0), 1);       //draws the bb for blob bigger than 200 pixels
66. //bd.drawSelectContours(200,color(255, 0, 0), 1); //draws contour for blob bigger than 200 pixels
67. bd.drawBox(color(0,255, 0), 1); // changed the color to green so you see what's happening                
68. bd.drawContours(color(255, 0, 0), 1);
69. }
70. void mouseDragged() {  
71. thres = map(mouseX,0, width, 0, 1);
72. }  

Hi clankill3r

let's start from the first question you asked:

Why does it need a sx, sy and width and height in the constructor.