Looking through PImage  docs I saw that set() method is generally considered slower for a paste operation then then dealing with pixel arrays. So for a bit of a personal excersise-type-thing I wrote the folowing:

<code>
//Simple "paste" operation
//Open up an image file --> canvas and then bring in another image file to be placed or
//"pasted" at specific (x,y) coordinates.

PImage canvasImage, pasteImage;

void generateCanvas(int img_width, int img_height)
{
 canvasImage=createImage(img_width,img_height,RGB);
 println("generated canvas image:"+ img_width+ " by "+ img_height);
}

void saveCanvas(String imgName)
{
 canvasImage.save(imgName);  
 println("saved out canvas image");
}

void pasteImage(String imgName, int x_offset, int y_offset)
{
 int x;          //horizontal
 int y;          //vertical
 
 int H_LIMIT, V_LIMIT;
 
 pasteImage=loadImage(imgName);

 //---------------
 //Figure out horizontal and vertical limits of the operation

 if((pasteImage.height+y_offset)>canvasImage.height)
 {
   V_LIMIT=canvasImage.height;
 }
 else
 {
   V_LIMIT=pasteImage.height+y_offset;
 }
 
 if((pasteImage.width+x_offset)>canvasImage.width)
 {
   H_LIMIT=canvasImage.width;
 }
 else
 {
   H_LIMIT=pasteImage.width+x_offset;
 }
 
 //---------------  
 
 y=0;
 
 for(;y_offset<V_LIMIT;y_offset++)
 {
   for(x=x_offset;x<H_LIMIT;x++)
   {
    canvasImage.pixels[y_offset*canvasImage.width+x]=pasteImage.pixels[pasteImage.width*y+x-(x_offset)];
   }
   y++;
 }
 
}

void setup()
{
 generateCanvas(500,500);
 
 pasteImage("img_cat.jpg",70,450);
 pasteImage("img_cat.jpg",50,50);  
 
 saveCanvas("test.png");
}

</code>

I haven't looked under the hood so to speak since I don't know much about Java. For those in the know, is this code a considerable time saver compared to set()?