* @return {@link BitMatrix} representing a grid of points sampled from the image within a region
* defined by the "from" parameters
* @throws ReaderException if image can't be sampled, for example, if the transformation defined
* @return {@link BitMatrix} representing a grid of points sampled from the image within a region
* defined by the "from" parameters
* @throws ReaderException if image can't be sampled, for example, if the transformation defined