I am quite new to processing, and have been reading up on this subject, understanding the syntax is sure not easy for me to pick up within a month. 

Below: Is the code that my supervisor has help me write, I do not take ownership of the codes. But I would like to play around with it.

Here's a video of me toying with it on:  halftone app

2. import sojamo.drop.*;
3. 
   
4. import processing.pdf.*;
5. 
   
6. SDrop drop;
7. 
   
8. import controlP5.*;
9. 
   
10. ControlP5 cp5;
11. 
    
12. Textlabel myTextlabelA;
13. Textlabel myTextlabelB;
14. 
    
15. int myColorBackground = color(0, 0, 0);
16. 
    
17. ControlWindow controlWindow;
18. 
    
19. public int sliderValue = 40;
20. 
    
21. PImage img;
22. 
    
23. 
    
24. void setup() {
25.   size(1024, 720);
26.   frameRate(30);
27.   drop = new SDrop(this);
28.   ellipseMode(CENTER); 
29.   img = loadImage(you can insert your image,);
30.   img.get () ;
31.   
32.   
33.   
34.   noStroke();
35.   smooth();
36.   cp5 = new ControlP5(this);
37. 
    
38.   myTextlabelA = cp5.addTextlabel("label")
39.                     .setText("HALFTONE PROGRAM")
40.                     .setPosition(250,25)
41.                     .setColorValue(255)
42.                     .setFont(createFont("Arial",22))
43.                     ;
44. 
    
45.   cp5 = new ControlP5(this);{
46. 
    
47. 
    
48. // PLEASE READ
49. // 
50. // With controlP5 2.0 the ControlWindow has been removed, 
51. // please see the changelog.txt for details. 
52. // Instead, see the extra/ControlP5frame example for 
53. // a ControlWindow alternative.
54. 
    
55. 
    
56. 
    
57. //  controlWindow = cp5.addControlWindow("controlP5window", 100, 100, 400, 200)
58. //    .hideCoordinates()
59. //    .setBackground(color(40))
60. //    ;
61. 
    
62.   cp5.addSlider("sliderValue")
63.      .setRange(0, 255)
64.      .setPosition(40, 40)
65.      .setSize(200, 29)
66.      //.moveTo(controlWindow)
67.      ;
68.   }
69.   
70. }
71. 
    
72. void draw() {
73.   
74.   imageMode (CENTER) ; {
75.   image(img, 50, 50, 80, 80); // Draw image using CENTER mode
76.   }
77.   
78.   background( 255 );
79.   
80.   fill( 255, 0, 0 );
81. 
    
82.   
83.   
84.   if(img !=null) {
85.     if(mousePressed) {
86.       scl = map(mouseX, 0 ,width, 0.5, 50);
87.     }
88.     
89.     
90.     
91.     for (int y=0;y<img.height;y+=steps) {
92.       for (int x=0;x<img.width;x+=steps) {
93.         float val = ( red( img.get(x, y) ) + green( img.get(x, y) ) + blue( img.get(x, y) ) ) / 3;
94.         float s = map(val, 0, 255, 1, 3 * scl );
95.         s = (3 * scl) - s;
96.         ellipse(x*scl, y*scl, s * dotSize , s * dotSize );
97.       }
98.     }
99.   }
100. }
101. 
     
102. float dotSize = 1;
103. 
     
104. float scl = 4;
105. 
     
106. int steps = 3;
107. 
     
108. void keyPressed() {
109.   switch(key) {
110.     case('='): dotSize+=0.03;break;
111.     case('-'): dotSize-=0.03;break;
112.     case('s'): export();break;
113.   }
114. }
115. 
     
116. 
     
117. 
     
118. 
     
119. void export() {
120.   println("generating halftone ... ");
121.   PGraphics c0 = createGraphics(int(img.width * scl) , int(img.height * scl), PDF, "output.pdf");
122.   c0.beginDraw();
123.   c0.image(img, 0, 0);
124.   c0.resize (0, 50);
125.   c0.background( 255 );
126.   c0.fill( 255, 0, 0 );
127.   c0.noStroke();
128. 
     
129.   
130.   for (int y=0;y<img.height;y+=steps) {
131.       for (int x=0;x<img.width;x+=steps) {
132.         float val = ( red( img.get(x, y) ) + green( img.get(x, y) ) + blue( img.get(x, y) ) ) / 4;
133.         float s = map(val, 0, 255, 1, 3 * scl );
134.         s = (3 * scl) - s;
135.         c0.ellipse(x*scl, y*scl, s * dotSize , s * dotSize );
136.       }
137.     }
138.  
139.   c0.endDraw(); // stop and save pdf
140.   c0.dispose();
141. 
     
142.   
143.    
144.  
145.   println("... done exporting.");
146. }
147. 
     
148. 
     
149. void dropEvent(DropEvent theDropEvent) {
150.   println("");
151.   println("isFile()\t"+theDropEvent.isFile());
152.   println("isImage()\t"+theDropEvent.isImage());
153.   println("isURL()\t"+theDropEvent.isURL());
154.   
155.   // if the dropped object is an image, then 
156.   // load the image into our PImage.
157.   if(theDropEvent.isImage()) {
158.     println("### loading image ...");
159.     img = theDropEvent.loadImage();
160.   }
161. }
162. 
     
163. 
     

I am using Sojamo Drop function (drop image into processing) and have change the export to PDF format versus, P2D (jpeg/pixelated)

The program works great, but the exported file is far too big.

For example;

drop image into processing: 55KB

exported image: approx 4.4mb

I understand what pdf export does; it exports out as vectorize image as well, making the filesize far too big, but again, when I open up the file, it takes far too long to open. OR When I want to edit the images in Adobe illustrator, it becomes, I notice they save the "drop" image together with vectored ellipse. 

Is there anyway I could, 1) Render the images quickly. 2) Export it without using too space but maintain its vectored dots. 3) I would also like to center the 'drop' image within the size of (1024,720) 

notes: I am just annoyed during the real time editing. (it gets really slow) but apart from that, converting it into jpeg, No problems with that.

Help?

Thanks.