Opencv android 经典代码 ImgColorToGray

package com.jerry; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.os.Environment; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageView; import java.io.File; public class ImgColorToGray extends Activity { /** Called when the activity is first created. */ Button btnChange; ImageView imgView; Bitmap imgSample; String path = ""; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btnChange = (Button) findViewById(R.id.btnChange); imgView = (ImageView) findViewById(R.id.imgChange); path = Environment.getExternalStorageDirectory().getPath() + File.separator + "lena.png"; imgSample = BitmapFactory.decodeFile(path); imgView.setImageBitmap(imgSample); btnChange.setOnClickListener(new OnClickListener() { public void onClick(View v) { imgSample = BitmapFactory.decodeFile(cvRgb2Gray(path)); imgView.setImageBitmap(imgSample); } }); } private native String cvRgb2Gray(String path); static { System.loadLibrary("opencv_java"); System.loadLibrary("rgb2gray"); } }