Get touch screen location inside imageview in Android

Question

I'm working on Android project.
I'm using custom View class to showing image and (move, scale, rotate) the image by using matrix.
This is the code I'm using:

public class CustomView extends View implements OnTouchListener {

    private Bitmap bitmap;
    private float imgWidth;
    private float imgHeight;
    private float screenWidth;
    private float screenHeight;
    private Matrix matrix = new Matrix();
    private Vector2D position = new Vector2D();
    private float scale=1;
    private float angle = 0;
    private TouchManager touchManager = new TouchManager(2);
    private boolean isInitialized = false;
    // Debug helpers to draw lines between the two touch points
    Vector2D vca;
    Vector2D vcb;
    Vector2D vpa;
    Vector2D vpb;
    int PressCount=0;
    Paint paint;

    public CustomView(Context context, Bitmap bitmap) 
    {       
        super(context);
        this.bitmap = bitmap;
        this.imgWidth = bitmap.getWidth();
        this.imgHeight = bitmap.getHeight();
        setOnTouchListener(this);
    }

    private float GetTheta(){
        return (float) (angle*180/Math.PI);
    }


    @Override 
    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);
        if (!isInitialized) 
        {
            screenWidth = getWidth();
            screenHeight = getHeight();
            position.set(screenWidth / 2, screenHeight / 2);
            scale=1;
            paint=new Paint();
            isInitialized = true;       
        }

        // Drawing the image
        matrix.reset();
        matrix.postTranslate(-imgWidth / 2.0f, -imgHeight / 2.0f);
        matrix.postRotate(GetTheta());
        matrix.postScale(scale, scale);
        matrix.postTranslate(position.getX(), position.getY());
        canvas.drawBitmap(bitmap, matrix, paint);

    }


    Vector2D DistancePoint;
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        vca = null;
        vcb = null;
        vpa = null;
        vpb = null;

        try {
            touchManager.update(event);
            PressCount=touchManager.getPressCount();
            if (PressCount == 1) 
            {
                vca = touchManager.getPoint(0);
                vpa = touchManager.getPreviousPoint(0);
                DistancePoint=touchManager.moveDelta(0);                
                position.add(DistancePoint);
            }
            else if (PressCount == 2)
            {
                    vca = touchManager.getPoint(0);
                    vpa = touchManager.getPreviousPoint(0);
                    vcb = touchManager.getPoint(1);
                    vpb = touchManager.getPreviousPoint(1);

                    Vector2D current = touchManager.getVector(0, 1);
                    Vector2D previous = touchManager.getPreviousVector(0, 1);
                    float currentDistance = current.getLength();
                    float previousDistance = previous.getLength();

                    if (previousDistance != 0) 
                    {
                        scale *= currentDistance / previousDistance;
                    }                           
                    angle -= Vector2D.getSignedAngleBetween(current, previous);
            }


            invalidate();
        }
        catch(Throwable t) {
            // So lazy...
        }
        return true;
    }

}

Above code is working perfect!
My question is how to convert screen touch coordinates to image coordinates?
In another word: when touching down on screen the (event.getX, event.getY) are relative to screen coordinates; Okay: I wanna correspond these coordinates to be relative to the image.

Also this image to explain what I want exactly:

Please comment me for any inquiry.
Will be appreciated for any help.