I'm trying to create a cheap little slideshow essentially where the image fades from black, delays for a bit, then fades back into black before reloading the image. I haven't gotten to the last part yet.  First I started with trying to tint an image in the default renderer, but it seemed to drop the bit depth or something as even at full alpha, it was blotchy.  then i decided to try a black rect over the image that changed in opacity.  I can't quite get that to work though.  
Code:

rectangle [] r;
int photoTimeSpan=3;
int playhead=0;
PImage b;
File dir = new File("C:/phototemp");
String[] children = dir.list();

void setup(){
size(700, 700, OPENGL);
//startFullscreen();
background(255,0,0);
frameRate(40);
r=new rectangle[1];
r[0]=new rectangle(0,0,width,height);
}

void draw(){
if (children == null) {
println("Directory listing failed");
} else {  
  float alphatemp=255f;
  if(r[0].alpha>=alphatemp){
  int picnum=round(random(children.length-1));
  b=loadImage(children[picnum]);
  image(b,0,0);
  println("Image born!");
  println(children[picnum]);
  delay(2000);
  }
  r[0].draw();
} 
}

class rectangle{
  float r,g,b,alpha;
  boolean AlphaStatus = true;
  rectangle(float x,float y, float wide,float high){
    alpha = 255f;
    r = 0;
    g = 0;
    b = 0;
  }
  void draw(){
    if(AlphaStatus == true && alpha<=0){
     delay(5000);
     AlphaStatus=false;
     } 
    if(AlphaStatus == false){
    fill(0, alpha);
    stroke(0, alpha);
    rect(0,0,width-20,height-20);
    alpha += 2;
    println("alpha increasing");
    }
    if(AlphaStatus == true){
    fill(0, alpha);
    stroke(0, alpha);
    rect(0,0,width-20,height-20);
    alpha -= 2;
    println("alpha decreasing");
    println(alpha);
    }
  }
}
 

Any suggestions?  Thanks