android 用颜色填充图像

Question

是否可以用两种颜色（例如绿色和蓝色）填充图像，但颜色只能绘制在黑色上，绿色只能绘制到某个坐标，而图像的其余部分应该绘制为蓝色？下面是一个图像示例，其中黑色必须替换为绿色和蓝色

Answer 1

是的，可以通过使用以下代码来实现：

用于填充的图像： https://i.sstatic.net/ 7rita.jpg

ma​​in.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_horizontal"
android:orientation="vertical" >

<RelativeLayout
    android:id="@+id/relative_layout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="5dp"
    android:layout_weight="1" >

    <ImageView
        android:id="@+id/coringImage"
        android:layout_width="300dp"
        android:layout_height="300dp" />
</RelativeLayout>

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >

    <Button
        android:id="@+id/btn_red"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="red" />

    <Button
        android:id="@+id/btn_yellow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="yellow" />

    <Button
        android:id="@+id/btn_blue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="blue" />
</LinearLayout>

</LinearLayout> 

活动类

public class FillColorActivity extends Activity implements OnTouchListener {
private RelativeLayout drawingLayout;
private MyView myView;
Button red, blue, yellow;
Paint paint;

/** Called when the activity is first created. */
/*
 * 
 * private ImageView imageView; private Canvas cv; private Bitmap mask,
 * original, colored; private int r,g,b; private int sG, sR, sB;
 */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    myView = new MyView(this);
    drawingLayout = (RelativeLayout) findViewById(R.id.relative_layout);
    drawingLayout.addView(myView);

    red = (Button) findViewById(R.id.btn_red);
    blue = (Button) findViewById(R.id.btn_blue);
    yellow = (Button) findViewById(R.id.btn_yellow);

    red.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            paint.setColor(Color.RED);
        }
    });

    yellow.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            paint.setColor(Color.YELLOW);
        }
    });
    blue.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            paint.setColor(Color.BLUE);
        }
    });
}

public class MyView extends View {

    private Path path;
    Bitmap mBitmap;
    ProgressDialog pd;
    final Point p1 = new Point();
    Canvas canvas;

    // Bitmap mutableBitmap ;
    public MyView(Context context) {
        super(context);

        paint = new Paint();
        paint.setAntiAlias(true);
        pd = new ProgressDialog(context);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeJoin(Paint.Join.ROUND);
        paint.setStrokeWidth(5f);
        mBitmap = BitmapFactory.decodeResource(getResources(),
                R.drawable.cartoon).copy(Bitmap.Config.ARGB_8888, true);

        this.path = new Path();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        this.canvas = canvas;
        paint.setColor(Color.GREEN);
        canvas.drawBitmap(mBitmap, 0, 0, paint);

    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:

            p1.x = (int) x;
            p1.y = (int) y;
            final int sourceColor = mBitmap.getPixel((int) x, (int) y);
            final int targetColor = paint.getColor();
            new TheTask(mBitmap, p1, sourceColor, targetColor).execute();
            invalidate();
        }
        return true;
    }

    public void clear() {
        path.reset();
        invalidate();
    }

    public int getCurrentPaintColor() {
        return paint.getColor();
    }

    class TheTask extends AsyncTask<Void, Integer, Void> {

        Bitmap bmp;
        Point pt;
        int replacementColor, targetColor;

        public TheTask(Bitmap bm, Point p, int sc, int tc) {
            this.bmp = bm;
            this.pt = p;
            this.replacementColor = tc;
            this.targetColor = sc;
            pd.setMessage("Filling....");
            pd.show();
        }

        @Override
        protected void onPreExecute() {
            pd.show();

        }

        @Override
        protected void onProgressUpdate(Integer... values) {

        }

        @Override
        protected Void doInBackground(Void... params) {
            FloodFill f = new FloodFill();
            f.floodFill(bmp, pt, targetColor, replacementColor);
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            pd.dismiss();
            invalidate();
        }
    }
}

// flood fill

public class FloodFill {
    public void floodFill(Bitmap image, Point node, int targetColor,
            int replacementColor) {
        int width = image.getWidth();
        int height = image.getHeight();
        int target = targetColor;
        int replacement = replacementColor;
        if (target != replacement) {
            Queue<Point> queue = new LinkedList<Point>();
            do {

                int x = node.x;
                int y = node.y;
                while (x > 0 && image.getPixel(x - 1, y) == target) {
                    x--;

                }
                boolean spanUp = false;
                boolean spanDown = false;
                while (x < width && image.getPixel(x, y) == target) {
                    image.setPixel(x, y, replacement);
                    if (!spanUp && y > 0
                            && image.getPixel(x, y - 1) == target) {
                        queue.add(new Point(x, y - 1));
                        spanUp = true;
                    } else if (spanUp && y > 0
                            && image.getPixel(x, y - 1) != target) {
                        spanUp = false;
                    }
                    if (!spanDown && y < height - 1
                            && image.getPixel(x, y + 1) == target) {
                        queue.add(new Point(x, y + 1));
                        spanDown = true;
                    } else if (spanDown && y < height - 1
                            && image.getPixel(x, y + 1) != target) {
                        spanDown = false;
                    }
                    x++;
                }
        } while ((node = queue.poll()) != null);
        }
    }
}

@Override
public boolean onTouch(View v, MotionEvent event) {
    // TODO Auto-generated method stub
    return false;
}
}

Answer 2

您将不得不使用位图、颜色转换矩阵和 Alpha 通道。

像这样（手头没有代码可以复制粘贴）：
1. 通过颜色矩阵从黑色像素创建 alpha 通道位图 ( black -> alpha 1 )
2. 在 alpha 通道上填充绿色矩形
3. 在 alpha 通道上填充蓝色矩形
4. 覆盖原始位图