Composite Target for Camera-Based Document/Object Capture System*

Abstract

The use of mobile phone camera technology in systems for capture of documents or three-dimensional objects is becoming increasingly popular. Compared to conventional flatbed or sheetfed scanner technology, such systems pose special image quality concerns due to the fact that the underlying camera and illumination technologies are inherently low-cost. Thus, each unit is designed to operate closer to the threshold of acceptable quality. So there are higher levels of noise and greater non-uniformity across the image plane, as well as greater unit-to-unit variability. Consequently, there is a need for a solution that can provide a detailed assessment of the spatial non-uniformity of key image quality metrics within the field of view of the image capture system, and which can be robustly and efficiently computed. This article proposes a specially designed composite target and an automatic analysis tool for image quality inspection of camera-based document/object capture systems. The target and analysis tool can be used during product development, as well as on the manufacturing line for real-time inspection.