how can i custom crop an image in android ?

Question

i have an activity to display an image, i am able to zoom the image and move it, i have a rectangle in the center of the screen which doesnt move, i want all what it is inside this rectangle to be able to crop the image , how can i do it ?

I have a custom class only for rectangle's draw here is my code :

@Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);
Rect mCropRectangle = new Rect();
        mCropRectangle.set(
                getLeft(),
                getTop()+(getBottom()+getTop())/6,
                getRight(),
                getBottom()-(getBottom()+getTop())/6
                );
}

I would use this Library [android-crop-library](https://github.com/jdamcd/android-crop), it's a good library to do this. — Skizo-ozᴉʞS ツ, Sep 01 '15 at 18:39
@Skizo is it there an easy way of doing what i want ? since i don't really want to use libraries — Blerim Blerii, Sep 01 '15 at 18:40
Take a look of this [question](http://stackoverflow.com/questions/16182120/custom-android-image-crop) but I'd use the library... — Skizo-ozᴉʞS ツ, Sep 01 '15 at 18:41
Of course.. that's why he uses a custom class just for him... try it out with the library — Skizo-ozᴉʞS ツ, Sep 01 '15 at 19:04

score 1 · Answer 1 · answered Sep 01 '15 at 19:56

You should be able to use PorterDuff to achieve this. I've pasted an example which will crop a big yellow background using a blue mask.

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //create a second canvas
        Bitmap mask = Bitmap.createBitmap(canvas.getWidth(), canvas.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(mask);

        Rect cropRect = new Rect(100, 100, 400, 400);

        Paint p = new Paint();
        p.setAntiAlias(true);
        p.setColor(Color.BLUE); //color doesn't matter
        c.drawRect(cropRect, p); //draw the crop rect first

        p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); //change transfer mode

        p.setColor(Color.YELLOW);//draw your original image/content here, pretty much whatever you wanted to draw
        c.drawRect(0, 0, getWidth(), getHeight(), p); 

        canvas.drawBitmap(mask, 0, 0, null); //draw the result back onto the canvas

    }

how can i custom crop an image in android ?

1 Answers1