Geometric and Radiometric Calibration for Low Cost Flatbed Scanners for Photogrammetric Applications

Abstract

In recent years, low cost scanners have been widely used in different applications such as, desk top publishing, graphics and rendering techniques.

For photogrammetric applications, because of the geometric (resolution and accuracy) and radiometric (dynamic range) constraints, only few high performance scanners (such as the Zeiss, Helava, Rollei and Vexcel ones) have been used.

The aim of this paper is to investigate the possibility to utilise low cost flatbed scanner for photogrammetric application, paying particular attention to the correction of the geometric distortions of the digital image acquired.

Using image processing techniques (such as filtering, enhancement and edge detection algorithms) the geometrically distorted digital image scanned by these devices, can be corrected by the mean of a calibration procedure, using a high precision reseau that gives the acquired image distortion function.

In addition, using feature extraction and matching procedures with subpixel precision, the fiducial marks position could be determined, in order to perform an interior orientation.

The image, geometrically and radiometrically corrected by the mean of high order interpolation algorithms, can be directly utilised for photogrammetric applications (digital stereoplotting devices), and geographical information systems (used as a raster layer) multidata integration (raster and vector merging).