You can get the top left corner of your view as follows:
int[] viewCoords = new int[2];
imageView.getLocationOnScreen(viewCoords);
From this and the touch coordinates you can calculate the point inside the ImageView:
int touchX = (int) event.getX();
int touchY = (int) event.getY();
int imageX = touchX - viewCoords[0]; // viewCoords[0] is the X coordinate
int imageY = touchY - viewCoords[1]; // viewCoords[1] is the y coordinate