I am developing a coloring app and was able to fill white color of the image with different colors using the below code.
Here is the Java class
import java.util.LinkedList;
import java.util.Queue;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class Main extends Activity {
private RelativeLayout dashBoard;
private MyView myView;
public ImageView image;
Button b_red, b_blue, b_green, b_orange, b_clear;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myView = new MyView(this);
setContentView(R.layout.activity_main);
findViewById(R.id.dashBoard);
b_red = (Button) findViewById(R.id.b_red);
b_blue = (Button) findViewById(R.id.b_blue);
b_green = (Button) findViewById(R.id.b_green);
b_orange = (Button) findViewById(R.id.b_orange);
b_red.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
myView.changePaintColor(0xFFFF0000);
}
});
b_blue.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
myView.changePaintColor(0xFF0000FF);
}
});
b_green.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
myView.changePaintColor(0xFF00FF00);
}
});
b_orange.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
myView.changePaintColor(0xFFFF9900);
}
});
dashBoard = (RelativeLayout) findViewById(R.id.dashBoard);
dashBoard.addView(myView);
}
public class MyView extends View {
private Paint paint;
private Path path;
public Bitmap mBitmap;
public ProgressDialog pd;
final Point p1 = new Point();
public Canvas canvas;
//Bitmap mutableBitmap ;
public MyView(Context context) {
super(context);
this.paint = new Paint();
this.paint.setAntiAlias(true);
pd = new ProgressDialog(context);
this.paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(5f);
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.forme).copy(Bitmap.Config.ARGB_8888, true);
this.path = new Path();
}
@Override
protected void onDraw(Canvas canvas) {
this.canvas = canvas;
this.paint.setColor(Color.RED);
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();
}
public void changePaintColor(int color){
this.paint.setColor(color);
}
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);
}
}
}
}
As you can see i used fill flood algorithm for coloring the a white space in an image.
The image is below:
Image to be used to fill the color
Now question is how can i fill the white space region with the below pattern(or any other pattern) instead of the color.
Pattern image
Please any help is appreciated as i am new to android. Thankyou
Well after a little workaround I was able to fill the pattern in the closed region using Flood Fill Algorithm. Below is what I did.
1.Introduced a new bitmap with the pattern as u can see below.
bitmapPattern = BitmapFactory.decodeResource(getResources(),R.drawable.pattern1).copy(Bitmap.Config.ARGB_8888, true);
And passed this bitmapPattern to the Flood Fill Algorithm as follows.
FloodFillPattern f = new FloodFillPattern();
f.floodFillPattern(bmp, pt, targetColor, replacementColor, pattern);
Note you have to scale this bitmap equal to the size of your image in which you will fill this pattern.
Then simply replace the pixels of your original image with the pixels of the pattern bitmap in the flood fill algorithm. As Follows:
image.setPixel(x, y, pattern.getPixel(x,y));
pattern is the patternBitmap you passed.
May it help someone :)