Copy Bitmap using Bitmap.createBitmap()

To copy Bitmap, it's easy by calling static methods Bitmap.createBitmap().

• createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter)
  Returns an immutable bitmap from subset of the source bitmap, transformed by the optional matrix.
• createBitmap(int width, int height, Bitmap.Config config)
  Returns a mutable bitmap with the specified width and height.
• createBitmap(Bitmap source, int x, int y, int width, int height)
  Returns an immutable bitmap from the specified subset of the source bitmap.
• createBitmap(int[] colors, int offset, int stride, int width, int height, Bitmap.Config config)
  Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.
• createBitmap(Bitmap src)
  Returns an immutable bitmap from the source bitmap.
• createBitmap(int[] colors, int width, int height, Bitmap.Config config)
  Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.

Example to copy the center part of Bitmap:

package com.example.androidcolor;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

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

public class MainActivity extends Activity {

 ImageView imgSource, imgTarget;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imgSource = (ImageView)findViewById(R.id.imgsource);
        imgTarget = (ImageView)findViewById(R.id.imgtarget);
        
        //Load bitmap from internet
        String onLineImgSource = "http://goo.gl/yxNeG";
        URL urlImgSource;
        
  try {
   urlImgSource = new URL(onLineImgSource);
   new MyNetworkTask(imgSource, imgTarget)
    .execute(urlImgSource);
  } catch (MalformedURLException e) {
   e.printStackTrace();
  }
        
    }
    
    private class MyNetworkTask extends AsyncTask<URL, Void, Bitmap>{
     
     ImageView ivSource, ivTarget;
     
     public MyNetworkTask(ImageView iSource, ImageView iTarget){
      ivSource = iSource;
      ivTarget = iTarget;
     }

  @Override
  protected Bitmap doInBackground(URL... urls) {
   Bitmap networkBitmap = null;
      
      URL networkUrl = urls[0]; //Load the first element
      try {
       networkBitmap = BitmapFactory.decodeStream(
         networkUrl.openConnection().getInputStream());
      } catch (IOException e) {
       e.printStackTrace();
      }

      return networkBitmap;
  }

  @Override
  protected void onPostExecute(Bitmap result) {
   ivSource.setImageBitmap(result);
   ivTarget.setImageBitmap(copyBitmap(result));
  }

    }
    
    private Bitmap copyBitmap(Bitmap src){

     //Copy the whole bitmap
     //Bitmap newBitmap = Bitmap.createBitmap(src);
     
     //Copy the center part only
     int w = src.getWidth();
     int h = src.getHeight();
     Bitmap newBitmap = Bitmap.createBitmap(src, w/4, h/4, w/2, h/2);
     
     return newBitmap;
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />
    
    <ScrollView 
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout 
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <ImageView
                android:id="@+id/imgsource"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imgtarget"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

Remark: Permission of "android.permission.INTERNET" is needed in this exercise to load Bitmap from internet.

Download the files.

Next:
- Example of using colorToHSV() and HSVToColor(), convert between argb color and HSV components.