1. When taking a pic, make sure that an entire page is inside the camera's field of view, and the camera looks at it at about a 90-degree angle.
2. The algorithm works best for neat, good handwriting. Write clearly so that each character is separated from the others and has some space around, and everything will work as it should.
3. If you get an error "valid QR-code is not found in the photo", try placing the notebook on a hard surface and take a pic again.