Invert the Image in ImageView (Android)

Before Inversion

After Inversion

 Create new Android Project

Project Name: PlayingwithBitmaps

Build Target: Android 2.3.3   //or greater than that

Application Name: PlayingwithBitmaps

Package Name: com.hamad.playingwithbitmaps

Create Activity: Main

Min SDK: 10 // or greater than that

  1. create main layout:

• One image view to display the image.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    android:id="@+id/rlMain" >

    <ImageView
        android:id="@+id/imViewAndroid"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@drawable/beautiful" />

</RelativeLayout>

 2. code of main activity:

package com.shaikhhamadali.blogspot.playingwithbitmaps;

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

public class Main extends Activity {
 ImageView imViewAndroid;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  imViewAndroid = (ImageView) findViewById(R.id.imViewAndroid);
  imViewAndroid.setImageBitmap(invertImage(BitmapFactory.decodeResource(getResources(), R.drawable.android_droid)));
 }
 public Bitmap invertImage(Bitmap src) {
  // create new bitmap with the same attributes(width,height)
  //as source bitmap
  Bitmap bmOut = Bitmap.createBitmap(src.getWidth(), src.getHeight(), src.getConfig());
  // color info
  int A, R, G, B;
  int pixelColor;
  // image size
  int height = src.getHeight();
  int width = src.getWidth();

  // scan through every pixel
  for (int y = 0; y < height; y++)
  {
   for (int x = 0; x < width; x++)
   {
    // get one pixel
    pixelColor = src.getPixel(x, y);
    // saving alpha channel
    A = Color.alpha(pixelColor);
    // inverting byte for each R/G/B channel
    R = 255 - Color.red(pixelColor);
    G = 255 - Color.green(pixelColor);
    B = 255 - Color.blue(pixelColor);
    // set newly-inverted pixel to output image
    bmOut.setPixel(x, y, Color.argb(A, R, G, B));
   }
  }

  // return final bitmap
  return bmOut;
 }
}

  3. note that:

• with the help of this,inverImage() method you can invert image on click,on action_down etc

  4. conclusion:

• Know how to invert an image bitmap from drawables.

  5. about the post:

• The code seems to explain itself due to comments, and is very easy to understand.
• Don’t mind to write a comment whatever you like to ask, to know,to suggest or recommend.
• Hope you enjoy it!

  6. Source Code:

        you can download the source code here

Cheers,

Hamad Ali Shaikh