// Displaying
int weight=0;
float sampleA,sampleB;
float shade;
int Continuum=0;
int range=200;
BImage imageA,imageB;  // Declare variable "a" of type BImage
void setup(){
size(400, 400);
imageA = loadImage("jfk2.jpg"); // Load the images into the program
imageB = loadImage("lincoln2.jpg"); // Load the images into the program  
//image(a,0,0,400,400);
noStroke();
}

void loop(){
Continuum++;
weight=abs(Continuum%(2*range)-(2*(Continuum%range)));  ///linear ocilations between 0 and range
 //println(weight);
for (int count=0;count<1600;count++)
{
  fill (255);
  rect ((count%40)*10,int(count/40)*10,10,10);
  sampleA=red(imageA.pixels[count]);  ///could be any channel.
  sampleB=red(imageB.pixels[count]);
  shade=(sampleB*(range-weight)+sampleA*weight)/(2.55*range);

  if (shade>50){
    shade=ceil(sqrt(shade));
    fill (255);
    rect ((count%40)*10,int(count/40)*10,10,10);
    fill (0);
    rect ((count%40)*10,int(count/40)*10,10-shade,10-shade);
  }else
    {
    shade=10-ceil(sqrt(shade));
    fill (0);
    rect ((count%40)*10,int(count/40)*10,10,10);
    fill (255);
    rect ((count%40)*10,int(count/40)*10,10-shade,10-shade);
  }
}
}