Bitmap processing: createScaledBitmap, getPixels and setPixels.

Example of using createScaledBitmap(), getPixels() and setPixels() on Bitmap.

package com.exercise.AndroidBitmap;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;

public class AndroidBitmapActivity extends Activity {
 
 ImageView image1, image2, image3, image4, image5;
 
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      image1 = (ImageView)findViewById(R.id.image1);
      image2 = (ImageView)findViewById(R.id.image2);
      image3 = (ImageView)findViewById(R.id.image3);
      image4 = (ImageView)findViewById(R.id.image4);
      image5 = (ImageView)findViewById(R.id.image5);
    
      Bitmap bmOriginal = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
      image1.setImageBitmap(bmOriginal);
    
      int width = bmOriginal.getWidth();
      int height = bmOriginal.getHeight();
      int halfWidth = width/2;
      int halfHeight = height/2;
    
      //Half Scaled
      Bitmap bmHalf = Bitmap.createScaledBitmap(bmOriginal,
        halfWidth, halfHeight, false);
      image2.setImageBitmap(bmHalf);
    
      //Upper left 1/4
      Bitmap bmPartial3 = Bitmap.createBitmap(halfWidth, halfHeight, Bitmap.Config.ARGB_8888);
      int[] pixels3 = new int[halfWidth * halfHeight];
      bmOriginal.getPixels(pixels3, 0, halfWidth, 0, 0, halfWidth, halfHeight);
      bmPartial3.setPixels(pixels3, 0, halfWidth, 0, 0, halfWidth, halfHeight);
      image3.setImageBitmap(bmPartial3);
    
      //Center 1/4
      Bitmap bmPartial4 = Bitmap.createBitmap(halfWidth, halfHeight, Bitmap.Config.ARGB_8888);
      int[] pixels4 = new int[halfWidth * halfHeight];
      bmOriginal.getPixels(pixels4, 0, halfWidth, halfWidth/2, halfHeight/2, halfWidth, halfHeight);
      bmPartial4.setPixels(pixels4, 0, halfWidth, 0, 0, halfWidth, halfHeight);
      image4.setImageBitmap(bmPartial4);
    
      //Bottom Right 1/4
      Bitmap bmPartial5 = Bitmap.createBitmap(halfWidth, halfHeight, Bitmap.Config.ARGB_8888);
      int[] pixels5 = new int[halfWidth * halfHeight];
      bmOriginal.getPixels(pixels5, 0, halfWidth, halfWidth, halfHeight, halfWidth, halfHeight);
      bmPartial5.setPixels(pixels5, 0, halfWidth, 0, 0, halfWidth, halfHeight);
      image5.setImageBitmap(bmPartial5);
    
  }
}

Related article:
- Image processing on Bitmap