Android实现图像二值化代码

package com.android.mypackage; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.ColorMatrix; import android.graphics.ColorMatrixColorFilter; import android.graphics.Paint; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageView; public class SkanBitmap extends Activity { /** Called when the activity is first created. */ private Bitmap bm;//要扫描的图片 private Bitmap pm;//扫描后得到的图片 private int width,height;//图片的宽和高 private Button button; private ImageView imageview; private int threashold =125; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); button=(Button)findViewById(R.id.button); imageview=(ImageView)findViewById(R.id.imageView); BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inMutable = true; bm=BitmapFactory.decodeResource(getResources(), R.drawable.sssd, opts);//从资源文件中得到一个位图 width=bm.getWidth();//获取位图的宽 height=bm.getHeight();//获取位图的高 button.setOnClickListener(new OnClickListener(){ @Override public void onClick(View arg0) { // TODO Auto-generated method stub //disable button button.setClickable(false); //new thread for binaryzation new Thread(new Runnable(){ @Override public void run() { // TODO Auto-generated method stub //convert image into gray Canvas c = new Canvas(bm); Paint p = new Paint(); ColorMatrix cm = new ColorMatrix(); cm.setSaturation(0); ColorMatrixColorFilter filter = new ColorMatrixColorFilter(cm); p.setColorFilter(filter); c.drawBitmap(bm, 0, 0, p); //binaryzation int[] colors = new int[bm.getWidth()]; for(int i=0; i<bm.getHeight(); i++){ bm.getPixels(colors, 0, bm.getWidth(), 0, i, bm.getWidth(), 1); for(int j=0; j<bm.getWidth(); j++){ int red = Color.red(colors[j]); if(red > threashold){ red = 255; }else{ red = 0; } colors[j]=Color.argb(255, red, red, red); } bm.setPixels(colors, 0, width, 0, i, width, 1); } mHandler.sendEmptyMessage(0); }}).start(); // imageview.postInvalidate(); //刷新图片 // imageview.setImageBitmap(pm); // new thread().start();//开始扫描图片的线程 } }); } Handler mHandler = new Handler(){ @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub super.handleMessage(msg); //refresh image imageview.setImageBitmap(bm); //enable button button.setClickable(false); }}; // 扫描图片的线程 class thread extends Thread{ public void run() { button.setClickable(false);//暂时将按钮的点击事件屏蔽掉，保证一次只开启一个线程 int[] colors=new int[width];//取一行图片的像素点 for(int i=0;i<height;i++){ //将位图bm的第i行的像素放入到数组 colors中去 bm.getPixels(colors, 0, width, 0, i, width, 1); for(int j=0;j<colors.length;j++){ //将颜色数组中的RGB值取反，255减去当前颜色值就获得当前颜色的反色 colors[j]=Color.rgb((28*Color.red(colors[j]))>>8, 151*Color.green(colors[j])>>8,(77*Color.blue(colors[j]))>>8); } pm.setPixels(colors, 0, width, 0, i, width, 1);//颜色取反后，将像素加入到pm的第i行中去 imageview.postInvalidate();//刷新图片 } button.setClickable(true);//重新监听按钮的点击事件 } } }