暂时不需要研究具体详细的怎么实现过程，直接使用已有的方法即可，代码如下

package com.yuanlp.testp_w_picpath;import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;public class MainActivity extends AppCompatActivity {private ImageView iv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);iv = (ImageView) findViewById(R.id.iv);}public void turnBig(View view){Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.meinv);Matrix matrix=new Matrix();matrix.setScale(2,2);  //放大四倍，水平方向2倍，竖直方向2倍//买一张纸Bitmap bitmap1 = Bitmap.createBitmap(bitmap.getWidth() * 2, bitmap.getHeight() * 2, bitmap.getConfig());//买个画板Canvas canvas = new Canvas(bitmap1);//临摹会话Paint paint = new Paint();paint.setColor(Color.BLACK);canvas.drawBitmap(bitmap,matrix,paint);//传入新纸iv.setImageBitmap(bitmap1);}public void turnSmall(View view){Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.meinv);Matrix matrix=new Matrix();matrix.setScale(0.5f,0.5f);//买个纸Bitmap bitmap1 = Bitmap.createBitmap(bitmap.getWidth() / 2, bitmap.getHeight() / 2, bitmap.getConfig());//买个画板Canvas canvas=new Canvas(bitmap1);Paint paint=new Paint();paint.setColor(Color.BLACK);canvas.drawBitmap(bitmap,matrix,paint);iv.setImageBitmap(bitmap1);}}