The purpose of the forum is to help people with their questions. In my opinion the PM system is much less suitable for this. First, because if questions are simple, then many people can answer them. Just get the answer from whoevers around. Second, because simple questions are best asked with small code examples. Code examples focus both the problem and the answer plus they help you move forward more concretely than just wordy replies. The PM system is terrible at handling code. Third, on the forum you might get multiple answers with alternative or additional solutions. Fourth, using the forum helps build the Processing knowledge base, which is one of it's greatest assets. And so forth....

For some basic info on images and pixels check out: http://processing.org/learning/pixels/

If you have questions just ask. If you got some code, even better.

Generally, the helpful people don't help privately. This is a forum for all to learn from, see?
You won't be flooding the forum if you keep it to a single thread.

Thanks for both responses. The reason why I don't feel like asking those silly questions is that I have seen many of them already which always lead to links to references. I am not only new here, I am New New. But ok, I'll try not to make a fool out of myself...

If I understand you correctly you want to get a kind of preview of the pixels you might be sending away with the click of a mouse. I adapted the code to show the pixel selection (40x40 area around the mouse) at the same size as the image. Is this what you mean?

(I removed the oscP5 code, because it's not relevant for this specific issue)

Adapted Code

1. PImage img;   
2.  
3. void setup() {
4.   size(700, 400);
5.   img = loadImage("http://25.media.tumblr.com/tumblr_m872wd37SR1rbzsl9o1_500.jpg");
6.   imageMode(CORNER);
7. }
8.  
9. void draw() {
10.   background(0);
11.   image(img, 10, 10, 200, 200);
12.   PImage pix = get(mouseX-20, mouseY-20, 40, 40);
13.   image(pix, 220, 10, 200, 200);
14. }
15.  
16. void mousePressed() { 
17.   for (int i=-20; i <= 20; i++) {  
18.     for (int j=-20; j <= 20; j++) { 
19.       color col = get(mouseX+i, mouseY+j);
20.     }
21.   }
22.   color col = get(mouseX, mouseY);
23. }

This works the way I wanted ! Thanks a lot ! 

Like this?

Adapted Code

1. PImage img, pix;
2.  
3. void setup() {
4.   size(700, 400);
5.   img = loadImage("http://25.media.tumblr.com/tumblr_m872wd37SR1rbzsl9o1_500.jpg");
6.   imageMode(CORNER);
7. }
8.  
9. void draw() {
10.   background(0);
11.   image(img, 10, 10, 200, 200);
12.   if (pix!=null) image(pix, 220, 10, 200, 200);
13. }
14.  
15. void mousePressed() { 
16.   pix = get(mouseX-20, mouseY-20, 40, 40);
17.   for (int i=-20; i <= 20; i++) {  
18.     for (int j=-20; j <= 20; j++) { 
19.       color col = get(mouseX+i, mouseY+j);
20.     }
21.   }
22.   color col = get(mouseX, mouseY);
23. }

Amnon's code had the preview image streching if it was near the top or right edges... I think I fixed that.
I also limited the preview to pixels on the image.
And added clicking-saved-current-preview.

Wow, that's even better, I cannot tell you how grateful I am !

A PImage object is basically a 2D array of color values.