US 6,493,469 B1 · Dual video camera system for scanning hardcopy documents

Abstract

A face-up document scanning apparatus stitches views from multiple video cameras together to form a composite image. The document scanning apparatus includes an image acquisition system and a frame merger module. The image acquisition, which is mounted over the surface of a desk on which a hardcopy document is placed, has two video cameras for simultaneously recording two overlapping images of different portions of the hardcopy document. By overlapping a portion of the recorded images, the document scanning apparatus can accommodate hardcopy documents of varying thickness. Once the overlapping images are recorded by the image acquisition system, the frame merger module assembles a composite image by identifying the region of overlap between the overlapping images. The composite image is subsequently transmitted for display on a standalone device or as part of a video conferencing system.

Claims21

Dependent claims

A document scanning apparatus, comprising:

an image acquisition system for simultaneously recording parts of a hardcopy document positioned face-up on a surface;
the parts of the hardcopy document being recorded without perspective distortion in a first image and a second image by said image acquisition system;
a portion of each of the parts of the hardcopy document recorded in the first image and the second image recording an identical segment of the hardcopy document;
and
a frame merger module for forming a composite image of the hardcopy document by stitching the first image and the second image together at the portions in each image that record the identical segment of the hardcopy document;
said frame merger module identifying the portion in the first image and the portion in the second image by computing correlation values of high gradient images of the first image and the second image for different regions of overlap between the first image and the second image.

3 more elements

A method for operating a document scanning apparatus, comprising the steps of:

simultaneously recording, with an image acquisition system, parts of a hardcopy document positioned face-up on a surface;
said recording step recording the parts of the hardcopy document without perspective distortion in a first image and a second image;
a portion of each of the parts of the hardcopy document recorded in the first image and the second image recording an identical segment of the hardcopy document;
and
forming, with a frame merger module, a composite image of the hardcopy document by stitching the first image and the second image together at the portions in each image that record the identical segment of the hardcopy document;
said forming step identifying the portion in the first image and the portion in the second image by computing correlation values of high gradient images of the first image and the second image for different regions of overlap between the first image and the second image.

3 more elements

Dependencies are inferred from the claim text.

Dual video camera system for scanning hardcopy documents

Life of this patent

Dual video camera system for scanning hardcopy documents

Life of this patent

Abstract

Claims21