<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

              android:orientation="vertical"

              android:layout_width="fill_parent"

              android:layout_height="fill_parent"

        >

    <ImageView

            android:id="@+id/image1"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            />

    <ImageView

            android:id="@+id/image2"

            android:layout_marginTop="30dp"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            />

</LinearLayout>

package com.example.imageResize;

import android.app.Activity;

import android.graphics.*;

import android.os.Bundle;

import android.widget.ImageView;

public class MyActivity extends Activity {

    private ImageView imageView1;

    private ImageView imageView2;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        this.imageView1 = (ImageView) findViewById(R.id.image1);

        this.imageView2 = (ImageView) findViewById(R.id.image2);

        //从一个文件中获取bitmap对象

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

        imageView1.setImageBitmap(bitmap);

        //创建一个新的bitmap

        Bitmap bitmap2 = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight()*2, bitmap.getConfig());

        //创建这个图片的画板

        Canvas canvas = new Canvas(bitmap2);

        Paint paint = new Paint();

        paint.setColor(Color.BLACK);

        Matrix matrix = new Matrix();

        matrix.setScale(1,2);

        //以之前的bitmap作为模板，长度不变，高度变为两倍

        canvas.drawBitmap(bitmap,matrix,paint);

        imageView2.setImageBitmap(bitmap2);

    }

}