Patent Document ID: 9824267
Application ID: 14975531
Patent Status: 1

Claim One:
1. A method for image processing, comprising: obtaining an image comprising a writing board and a background external to the writing board; detecting a plurality of lines within the image; identifying and removing, from the plurality of lines, a first subset of lines located on the writing board in the image by: selecting a first line of the plurality of lines; identifying a first plurality of intensity values for a first plurality of pixels on a first side of the first line; identifying a second plurality of intensity values for a second plurality of pixels on a second side of the first line; determining the first line is located on the writing board based on the first plurality of pixel values and the second plurality of pixel values; and removing the first line from the plurality of lines in response to determining the line is located on the writing board; identifying and removing, from the plurality of lines, a second subset of lines located in the background of the image; determining, based on the plurality of lines after the first subset and the second subset are removed, a plurality of corners of the writing board within the image; and correcting a perspective of the writing board by applying a transformation to the image based on the plurality of corners.