Android-将RGB彩色图转换为灰度图

[align=center]Android-将RGB彩色图转换为灰度[/align]


[align=center] [/align]
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>

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