int[] personX;
int[] personZ;

PImage[] images;

void setup()
{
  //size...
  images=new PImage[8];
  images[0]=loadImage(".....");
  //load all images

  personX=new int[50]; //50 people
  personZ=new int[50];
  for(int i=0;i<50;i++)
  {
    personX[i]=random(width);
    personZ[i]=random(height);
  }
}

void draw()
{
  background(255);
  //some transalte stuff to set your 0,0,0 point..
  for(int i=0;i<50;i++)
  {
    pushMatrix();
    translate(personX[i],0,personZ[i]);
    image(0,0,images[i%8]);
    popMatrix();
  }
}