Image processing for handheld scanner

摘要

A computer peripheral that may operate as a scanner. The scanner captures image frames as it is moved across an object. The image frames are formed into a composite image based on computations in two processes. In a first process, fast track processing determines a coarse position of each of the image frames based on a relative position between each successive image frame and a respective preceding image determine by matching overlapping portions of the image frames. In a second process, fine position adjustments are computed to reduce inconsistencies from determining positions of image frames based on relative positions to multiple prior image frames. The peripheral may also act as a mouse and may be configured with one or more navigation sensors that can be used to reduce processing time required to match a successive image frame to a preceding image frame.

主权项

1. A method of forming a composite image by combining a plurality of successive image frames, the method comprising:
with at least one processor:
for image frames of the plurality of successive image frames after a first image frame,
determining a coarse position of the image frame based on a position of at least a preceding image frame, the determining comprises matching portions of the image frame to corresponding portions of the at least a preceding image frame; andfor a subsequent image frame of the plurality of successive image frames:
determining a difference between the determined coarse position of the subsequent image frame and a position determined by matching the subsequent image to at least one prior image frame other than an image frame preceding the subsequent image frame;when the determined difference is below a threshold, identifying a stable set of image frames of the successive image frames between the at least one prior image frame and the image frame preceding the subsequent image frame, such that the stable set of image frames is excluded in subsequent adjusting of the position of image frames; andwhen the determined difference is above the threshold, adjusting, based on the determined difference, the coarse position of image frames of the successive image frames between the at least one prior image frame and the image frame preceding the subsequent image frame.