Squares.

import java.awt.image.*;
import javax.imageio.*;
import java.io.*;
import java.awt.*;
import java.lang.Math;

class Main {

  static int iter = 10;

  public static void main(String[] args) {
    BufferedImage bi = new BufferedImage(500, 500, BufferedImage.TYPE_INT_ARGB);

    for (int y = 0; y < 500; y++) {
      for (int x = 0; x < 500; x++) {
        //bi.setRGB(x, y, (int)(Math.random()*-16777217));
        //bi.setRGB(x, y, new Color((int)(Math.random()*256), (int)(Math.random()*256), (int)(Math.random()*256)).getRGB());
        bi.setRGB(x, y, -1);
      }
    }

    int sqNum = 100;
    int[][] squares = new int[sqNum][4];

    for (int i = 0; i < sqNum; i++) {
      squares[i][0] = (int)(Math.random()*500+.5f); //x
      squares[i][1] = (int)(Math.random()*500+.5f); //y
      squares[i][2] = (int)(Math.random()*100+.5f); //w
      squares[i][3] = (int)(Math.random()*100+.5f); //h
    }

    for (int i = 0; i < sqNum; i++) {

      for (int y = squares[i][1]-squares[i][3]; y <= squares[i][1]+squares[i][3]; y++) {
        for (int x = squares[i][0]-squares[i][2]; x <= squares[i][0]+squares[i][2]; x++) {
          if (x >= 0 && x < 500 && y >= 0 && y < 500) {
            if (x == squares[i][0]-squares[i][2] || x == squares[i][0]+squares[i][2] || y == squares[i][1]-squares[i][3] || y == squares[i][1]+squares[i][3]) {
              bi.setRGB(x, y, -16777216);
            } else {
              bi.setRGB(x, y, -1);
            }
          }
        }
      }

    }

    try {
      ImageIO.write(bi, "png", new File("C:\\Users\\Connor\\Desktop\\pic_0.png"));
    } catch(IOException e) {
    }

    /*for (int n = 0; n < 10; n++) {
      for (int i = 0; i < iter; i++) {
        bi = smooth(bi);
      }

      try {
        ImageIO.write(bi, "png", new File("C:\\Users\\Connor\\Desktop\\pic_" + (iter*(n+1)) + ".png"));
      } catch(IOException e) {
      }
    }*/

  }

  public static BufferedImage smooth(BufferedImage bi) {
    BufferedImage img = new BufferedImage(bi.getWidth(), bi.getHeight(), bi.getType());
    for (int y = 0; y < 500; y++) {
      for (int x = 0; x < 500; x++) {
        img.setRGB(x, y, getAverageColor(x, y, bi));
      }
    }
    return img;
  }

  public static int getAverageColor(int x, int y, BufferedImage template) {
    int[] n = new int[3];
    int d = 0;
    if (x > 0) {
      Color col = new Color(template.getRGB(x-1, y));
      n[0]+=col.getRed();
      n[1]+=col.getGreen();
      n[2]+=col.getBlue();
      d++;
    }
    if (x < template.getWidth()-1) {
      Color col = new Color(template.getRGB(x+1, y));
      n[0]+=col.getRed();
      n[1]+=col.getGreen();
      n[2]+=col.getBlue();
      d++;
    }
    if (y > 0) {
      Color col = new Color(template.getRGB(x, y-1));
      n[0]+=col.getRed();
      n[1]+=col.getGreen();
      n[2]+=col.getBlue();
      d++;
    }
    if (y < template.getHeight()-1) {
      Color col = new Color(template.getRGB(x, y+1));
      n[0]+=col.getRed();
      n[1]+=col.getGreen();
      n[2]+=col.getBlue();
      d++;
    }
    return new Color((int)(n[0]*1f/d+.5), (int)(n[1]*1f/d+.5), (int)(n[2]*1f/d+.5)).getRGB();
  }

}