How to zoom out an image by Bilinear Interpolation in java? -

i trying read image, zoom in 80*60 , zoom out resulted image 5 times bilinear interpolation method. error : exception in thread "main" java.lang.arrayindexoutofboundsexception: 4800 . can me please?

this have done :

import java.awt.color; import java.awt.graphics2d; import java.awt.image; import java.awt.renderinghints; import java.awt.image.bufferedimage; import java.awt.image.databufferbyte; import java.awt.image.writableraster; import java.io.bytearrayinputstream; import java.io.file; import java.io.ioexception; import java.io.inputstream;  import javax.imageio.imageio;  public class biinterpolationtest {      public static int zh;     public static int zw;       public static void main(string[] args) throws ioexception {         // todo auto-generated method stub           int[][] savedimage;          file  f = new file ("f:\\java\\gray scale images\\3.jpg");          savedimage = readimage(f);         bufferedimage grayimage = new bufferedimage(savedimage.length, savedimage[0].length, bufferedimage.type_byte_gray);          (int =0 ; i<savedimage.length ; ++){         (int j=0 ; j<savedimage[0].length ; j++){                 int rgb = savedimage[i][j];                 rgb = (rgb<<16)|(rgb<<8)|(rgb);                 grayimage.setrgb(i, j, rgb);                  bufferedimage zoomin =scaledimage(grayimage, 80,60);                  zh = zoomin.getheight();                  zw = zoomin.getwidth();           byte[] temparr;             temparr = extractbytes(zoomin);                 // todo auto-generated catch block          byte [] zoomout;         zoomout = bilinerainterpolation(temparr , 5);          inputstream in = new bytearrayinputstream(zoomout);         bufferedimage bimageinterpolated;         try {             bimageinterpolated = imageio.read(in);             imageio.write(bimageinterpolated, "jpg", new file(                     "f:/new-darksouls.jpg"));         } catch (ioexception e) {             // todo auto-generated catch block             e.printstacktrace();         }          }          }      }          public static bufferedimage scaledimage(image img, int w , int h){          bufferedimage resizedimage = new bufferedimage(w , h , bufferedimage.type_byte_gray);         graphics2d g2 = resizedimage.creategraphics();         g2.setrenderinghint(renderinghints.key_interpolation, renderinghints.value_interpolation_bilinear);         g2.drawimage(img, 0, 0, w, h, null);         g2.dispose();         return resizedimage;         }         /////////////////////////////////////         public static byte[] extractbytes (bufferedimage image) throws ioexception {               bufferedimage bufferedimage = new bufferedimage(image.getheight(), image.getwidth(), bufferedimage.type_byte_gray);               // databufferbytes raster              writableraster raster = bufferedimage .getraster();              databufferbyte data   = (databufferbyte) raster.getdatabuffer();               return ( data.getdata() );             }            public static int[][] readimage(file filename){             bufferedimage img;              try {                 img = imageio.read(filename);                  // gray_scaled image output                  int width = img.getwidth();                 int height = img.getheight();                 imagepro.fw=width;                 imagepro.fh = height;                 int [][] readimageval = new int [width][height];                 (int = 0; i<height ; i++){                     (int j =0  ; j<width ; j++){                          color c = new color(img.getrgb(j, i));                            int r= (int)(c.getred() * 0.299)&0xff;                            int g = (int)(c.getgreen() * 0.587)&0xff;                            int b = (int)(c.getblue() *0.114)&0xff;                            int avg = ((r+b+g));                          readimageval[j][i] = avg;                             }                             }                 return readimageval;              } catch (ioexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             }             return null;         }        public static byte[] bilinerainterpolation(byte[] imgdata, int ratio) {         int wf = zw*ratio;        int hf = zh*ratio;        byte[] temparr = new byte[wf*hf] ;        int a, b, c, d, x, y, index, g ;        float x_ratio = ((float)(zw))/wf ;        float y_ratio = ((float)(zh))/hf ;        float x_diff, y_diff ;        int in = 0 ;        (int i=0;i<hf;i++) {            (int j=0;j<wf;j++) {                x = (int)(x_ratio * j) ;                y = (int)(y_ratio * i) ;                x_diff = (x_ratio * j) - x ;                y_diff = (y_ratio * i) - y ;                index = y*zw+x ;                 // range 0 255 bitwise , 0xff                = imgdata[index] & 0xff ;                b = imgdata[index+1] & 0xff ;                c = imgdata[index+zw] & 0xff ;                d = imgdata[index+zw+1] & 0xff ;                          g = (int)(                        a*(1-x_diff)*(1-y_diff) +  b*(x_diff)*(1-y_diff) +                        c*(y_diff)*(1-x_diff)   +  d*(x_diff*y_diff)                        ) ;                 temparr[in++] = (byte) g ;                                               }        }        return temparr ;    }      }