Systems and methods for detecting tape on a document

Abstract

Systems and methods for detecting tape on a document are provided. In one embodiment, a method includes capturing a first image of a document. The first image is captured while at least a portion of the document is subjected to a first electromagnetic radiation. The method includes capturing a second image of the document. The second image is captured while at least a portion of the document is subjected to a second electromagnetic radiation. The method also includes comparing the first image to the second image to determine whether tape is adhered to the document.

What is claimed is: 
     
         1 . A method for detecting tape on a document along a document path, the method comprising:
 providing an apparatus, the apparatus comprising:
 a first electromagnetic radiation source forming a first angle with the document path, 
 a second electromagnetic radiation source forming a second angle with the document path, 
 an image sensor for capturing images of the document, and 
 a controller coupled to the first electromagnetic radiation source, the second electromagnetic radiation source, and the image sensor; 
   positioning the first electromagnetic radiation source to at least semi-directly illuminate the document relative to the image sensor;   positioning the second electromagnetic radiation source to cause specular reflection relative to the image sensor;   moving the document along the document path;   activating and deactivating the first electromagnetic radiation source and second electromagnetic radiation source in a sequential manner;   capturing at least two images of the document using the image sensor; and   comparing the at least two images with each other to form a transformed image and detecting the presence of tape with the transformed image.   
     
     
         2 . The method of  claim 1 , wherein activating and deactivating the first electromagnetic radiation source and second electromagnetic radiation source comprises activating and deactivating according to a sequence specified in a lookup table. 
     
     
         3 . The method of  claim 1 , wherein the apparatus further comprises a third electromagnetic radiation source that emits ultraviolet light and activating and deactivating further comprises activating and deactivating the third electromagnetic radiation source. 
     
     
         4 . The method of  claim 1 , wherein the apparatus further comprises a third electromagnetic radiation source that emits ultraviolet light and activating and deactivating further comprises activating and deactivating the third electromagnetic radiation source; and
 wherein activating and deactivating the first electromagnetic radiation source, second electromagnetic radiation source, and third electromagnetic source comprises activating and deactivating according to a sequence specified in a lookup table.   
     
     
         5 . The method of  claim 1 , wherein the controller comprises a computing device having a tape detection application, and wherein the tape detection application comprises:
 an illumination controller for controlling the activation and deactivation of the first electromagnetic radiation source and the second electromagnetic source;   an imaging module for controlling the capturing of images by the image sensor; and   and a tape detection engine for detecting tape using captured images.   
     
     
         6 . The method of  claim 1 , wherein the controller comprises a computing device having a tape detection application, and wherein the tape detection application comprises:
 an illumination controller for controlling the activation and deactivation of the first electromagnetic radiation source and the second electromagnetic source;   an imaging module for controlling the capturing of images by the image sensor, wherein the imaging module operates in conjunction with the imaging module to capture the at least two images as the document is illuminated according to a sequence; and   and a tape detection engine for detecting tape using captured images.   
     
     
         7 . The method of  claim 1 , wherein the first electromagnetic radiation source comprises a hybrid light operable to selectively emit ultraviolet light and white light. 
     
     
         8 . The method of  claim 1 , wherein the steps of capturing and comparing comprise:
 capturing a plurality of images along the document to form an interleaved image formed using images captured while using the first electromagnetic radiation source and images captured while using the second electromagnetic source; separating the interleaved image into two or more images; and comparing the two or more separated images.   
     
     
         9 . The method of  claim 1 , wherein the image sensor is a line scan camera configured to capture images with a vertical spread from a top edge of the document to a bottom edge of the document. 
     
     
         10 . The method of  claim 1 , wherein the image sensor is a line scan camera configured to capture images in greyscale with a vertical spread from a top edge of the document to a bottom edge of the document. 
     
     
         11 . The method of  claim 1 , wherein first angle and the second angle are not equal.