Sunday, September 23, 2012

Scaling Bitmap Image in Android


Scale Bitmap

To scale bitmap, we can use the following code:
Matrix matrix = new Matrix();
matrix.postScale(xScale, yScale);
Bitmap newBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, orgWidth, orgHeight, matrix, true);


package com.AndroidScaleBitmap;
 
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.widget.ImageView;
 
public class AndroidScaleBitmapActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
         
        ImageView image1 = (ImageView)findViewById(R.id.image1);
        ImageView image2 = (ImageView)findViewById(R.id.image2);
         
        Bitmap oldBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
         
        int orgWidth = oldBitmap.getWidth();
        int orgHeight = oldBitmap.getHeight();
        int newWidth = 300;
        int newHeight = 300;
        float xScale = newWidth/orgWidth;
        float yScale = newHeight/orgHeight;
         
        Matrix matrix = new Matrix();
        matrix.postScale(xScale, yScale);
        Bitmap newBitmap = Bitmap.createBitmap(oldBitmap, 0, 0, orgWidth, orgHeight, matrix, true);
         
        image1.setImageBitmap(oldBitmap);
        image2.setImageBitmap(newBitmap);
    }
}






<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
 
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <ImageView
        android:id="@+id/image1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <ImageView
        android:id="@+id/image2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
 
</LinearLayout>