android - how to get the image edge x/y position inside imageview

If i have an ImageView that fills the screen.
The ImageView background is set to green color.
I place a bitmap in the ImageView, keeping bitmap proportions.

A portrait photo in this layout will show green on both left and right side
(Phone orientation= portrait).

Now, How do i get the left side x/y position of the edge when the green ends and bitmap begins.

The background for this endeavor project is that i want to write text on the image and save the image back to a new image with the text. The problem is..

Since I scale the image inSampleSize = 4; and the ImageView shrinking it even more, saving this new picture will give a small small approx 250x350 image.

What i want is to use the x/y positions and transfer the written text to the original inSampleSize = 4 image or to the sdcard 1500x3000 image

I know and read other questions about this that i have to "Do the math calculations" myself I just need this small answer.

I forgot i can take a screenshot to clarify.

this is what it look like: (I get a new pen on pressing the button "pen" each pen hold its own unique text and position on the screen

Here is the imageview

    import java.util.HashMap;
    import java.util.UUID;
    import android.app.Activity;
    import android.content.Context;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Paint;
    import android.graphics.Point;
    import android.graphics.Rect;
    import android.graphics.Typeface;
    import android.graphics.drawable.BitmapDrawable;
    import android.graphics.drawable.Drawable;
    import android.os.Environment;
    import android.util.AttributeSet;
    import android.view.Display;
    import android.view.MotionEvent;