Android-将RGB彩色图转换为灰度图
实例：RGB2Grey
项目运行效果图：
源代码：
public class MainActivity extends Activity { /* (non-Javadoc) * @see android.app.Activity#onCreate(android.os.Bundle) */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //通过Id来获取界面中组件的引用 Button rgb2greyBtn = (Button) findViewById(R.id.rgb2greybtn); ImageView imageView1 = (ImageView) findViewById(R.id.imageView1); final ImageView imageView2 = (ImageView) findViewById(R.id.imageView2); //通过位图工厂，创建一个位图 final Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_android); imageView1.setImageBitmap(bitmap); //为“转换为灰度图”按钮添加监听事件 rgb2greyBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub //将转换过后的灰度图显示出来 imageView2.setImageBitmap(convertGreyImg(bitmap)); } }); } /** * 将彩色图转换为灰度图 * @param img 位图 * @return 返回转换好的位图 */ public Bitmap convertGreyImg(Bitmap img) { int width = img.getWidth(); //获取位图的宽 int height = img.getHeight(); //获取位图的高 int []pixels = new int[width * height]; //通过位图的大小创建像素点数组 img.getPixels(pixels, 0, width, 0, 0, width, height); int alpha = 0xFF << 24; for(int i = 0; i < height; i++) { for(int j = 0; j < width; j++) { int grey = pixels[width * i + j]; int red = ((grey & 0x00FF0000 ) >> 16); int green = ((grey & 0x0000FF00) >> 8); int blue = (grey & 0x000000FF); grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11); grey = alpha | (grey << 16) | (grey << 8) | grey; pixels[width * i + j] = grey; } } Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565); result.setPixels(pixels, 0, width, 0, 0, width, height); return result; }}
布局文件：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/LinearLayout1" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <ImageView android:id="@+id/imageView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" /> <Button android:id="@+id/rgb2greybtn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/rgb2greybtn" android:layout_gravity="center_horizontal"/> <ImageView android:id="@+id/imageView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" />"</LinearLayout>