Hi to everyone, i'm new on this forum.
I have a problem with a .pde written by myself. I have to obtain four little images on the right of my output modified with the andy warhol effect and equal to a bigger image that i have to obtain on the right of the output.

I obtain this output:


even if the starting image (that i should see on the left) is this:


This is the code i wrote:

1. PImage g_image;
   PImage g_imageSxUP = new PImage(200,200);
   PImage g_imageSxDW = new PImage(200,200);
   PImage g_imageDxUP = new PImage(200,200);
   PImage g_imageDxDW = new PImage(200,200);
   PImage g_output = new PImage(800,400);
   
   int g_width = 800;
   int g_height = 400;
   
   PFont g_font;
   
   int g_index = 1;
   
   color g_colors[] = new color[10];
   color g_colorsIn[] = new color[10];
   
   
   void setup() {
   
     g_font = loadFont("Univers-66.vlw");
     textFont(g_font, 12);
   
     size(g_width, g_height, P2D);
   
     colorMode(RGB, 255, 255, 255, 255);
   
   
     loadDiskImage(g_index); 
   
   
     background(0, 0, 0);
    
     g_colors[0] = color(255,0,0);
     g_colors[1] = color(0,128,0);
     g_colors[2] = color(0,0,255);
     g_colors[3] = color(0,0,0);
     g_colors[4] = color(1,1,1);
     g_colors[5] = color(255,255,0);
     g_colors[6] = color(255,165,0);
     g_colors[7] = color(128,0,128);
     g_colors[8] = color(238,130,238);
     g_colors[9] = color(0,255,0);
    
   }
   
   int getColorW(color p_colIn, color p_col[])
   {
     int index = 0;
     float distanza = 999999999;
     int pixelImgOut;
   
    
           float cR_px = red(p_colIn);
           float cG_px = green(p_colIn);
           float cB_px = blue(p_colIn);
           for(int i = 0; i < 10; i++)
           {
               float aR = red(g_colorsIn[i]);
               float aG = green(g_colorsIn[i]);
               float aB = blue(g_colorsIn[i]);
               float rr = cR_px - aR;
               float gg = cG_px - aG;
               float bb = cB_px - aB;
               float d = (rr * rr) + (gg * gg) + (bb * bb);
               if(d < distanza)
               {
                   distanza = d;
                   index = i;
                  
               }
     
         
       
       }
   
      return index;
     
   }
   
   void getRandomPixels()
   {
     int index;
   
     for( int i=0; i<10; i++ )
     {
       index = int(random(0,400*400-1));
       g_colorsIn[i] = g_image.pixels[index];
     }
      
   }
   
   void doEffect()
   {
     int loc, out;
     float r,g,b,rc,gc,bc;  
     float dr;
     float dg;
     float db;
     float distance;
   
     color colArray1[] = {g_colors[0],g_colors[1],
                          g_colors[2],g_colors[3],
                          g_colors[4],g_colors[5],
                          g_colors[6],g_colors[7],
                          g_colors[8],g_colors[9]};
   
     color colArray2[] = {g_colors[1],g_colors[0],
                          g_colors[3],g_colors[2],
                          g_colors[5],g_colors[4],
                          g_colors[7],g_colors[6],
                          g_colors[9],g_colors[8]};
   
     color colArray3[] = {g_colors[2],g_colors[3],
                          g_colors[0],g_colors[1],
                          g_colors[6],g_colors[7],
                          g_colors[4],g_colors[5],
                          g_colors[9],g_colors[8]};
   
     color colArray4[] = {g_colors[3],g_colors[2],
                          g_colors[1],g_colors[0],
                          g_colors[7],g_colors[6],
                          g_colors[5],g_colors[4],
                          g_colors[9],g_colors[8]};
   
     getRandomPixels(); 
    
     for (int i = 0; i < g_height; i++)
     {
       for (int j = 0; j < g_height; j++)
       {
         loc = i + j * g_height;
   
         if( loc%2 == 0 )
         {
           out = i/2 + j/2 * 200;
          
           int best_i = getColorW(g_image.pixels[loc], colArray1);
           g_imageSxUP.pixels[out] = colArray1[best_i];
   
           best_i = getColorW(g_image.pixels[loc], colArray2);
           g_imageSxDW.pixels[out] = colArray2[best_i];
   
           best_i = getColorW(g_image.pixels[loc], colArray3);
           g_imageDxUP.pixels[out] = colArray3[best_i];
   
           best_i = getColorW(g_image.pixels[loc], colArray4);
           g_imageDxDW.pixels[out] = colArray4[best_i];
         }
       }
     } 
   
     preProcessImages();
   
   }
   
   
   void preProcessImages()
   {    loadPixels();
           for(int i1 = 0; i1 < g_height; i1++)
           {
               for(int k1 = 0; k1 < g_height; k1++)
               {
                   int i = i1 + k1 * g_height;
                   int k = i1 + k1 * 800;
                   g_output.pixels[k] = g_image.pixels[i];
               }
   
           }
   
           int j1 = g_height / 2;
           for(int l1 = 0; l1 < j1; l1++)
           {
               for(int i2 = 0; i2 < j1; i2++)
               {
                   int j = l1 + i2 * j1;
                   int l = g_height + l1 + i2 * 800;
                   g_output.pixels[l] = g_imageSxUP.pixels[j];
                   l = g_height + j1 + l1 + i2 * 800;
                   g_output.pixels[l] = g_imageSxDW.pixels[j];
                   l = g_height + l1 + (j1 + i2) * 800;
                   g_output.pixels[l] = g_imageDxUP.pixels[j];
                   l = g_height + j1 + l1 + (j1 + i2) * 800;
                   g_output.pixels[l] = g_imageDxDW.pixels[j];
               }
   
           }
   
           updatePixels();
   }
   
   
   
   void loadDiskImage( int p_image )
   {
     g_image = loadImage("image_"+p_image+".jpg");
   }
   
   void draw()
   {
   
     background(g_output);
   
   
   }
   
   
   void keyPressed()
   {
     if(key == 'p')
     {
   
       doEffect();
   
     }
     else
     if( key == '+' )
     {
   
       g_index++;
       if( g_index >4 ) g_index = 4;
       loadDiskImage(g_index);
       doEffect();
   
     }
     else
     if( key == '-' )
     {
    
       g_index--;
       if( g_index <1 ) g_index = 1;
       loadDiskImage(g_index); 
       doEffect();
   
     }
   } 

Could someone help me to find what i wrong?
Thanks in advance for your attention.

Goodbye to all.