Question

In the program below, I try to change the pixel colors form a image with the click of the mouse, however, I’m trying to return to the original image with the second click but I haven’t been able to find the rigth argument to do it…

PImage pic;

void setup(){
  pic=loadImage("road.jpg"); // Loading the image from a folder "date" attached to the sketch
  size (pic.width,pic.height);
image(pic,0,0);
}
void draw(){
}
void mousePressed(){

  loadPixels();
  pic.loadPixels();
        for (int y = 0; y < height; y++ ) {
          for (int x = 0; x < width; x++ ) {
            int loc = x + y*width;
             if(red(pixels[loc]) >170 && red(pixels[loc])<215){ 
               pixels[loc]=color(187,0,0);    //changing the pixels color from red to green
               }               

             }          
    }
    for (int y = 0; y < height; y++ ) {
          for (int x = 0; x < width; x++ ) {
            int loc = x + y*width;
             if(green(pixels[loc]) >120 && green(pixels[loc])<160){ 
               pixels[loc]=color(0,192,0);    //changing the pixels color form green to red
             }
          }
    }       
       // I belive that here I have to add an argument that returns to the original image 
  updatePixels();
}

I will appreciate any help.

Thanks.

Answer 1

What I typically do for this sort of thing is to create /two/ images, one being the file (target) and the other being a blank Image.

PImage target;
PImage destination;
target = loadImage("file.jpg");
destination = createImage(target.width, target.height, RGB);

And then I copy the target’s information into the destination’s pixels. If I want to switch back, I can just call target; I’m able to freely swap back and forth by saving them as two separate images.

For an example, check out a sketch of mine on openprocesing: http://openprocessing.org/visuals/?visualID=49301