TONE REPRODUCTION OF PHOTOGRAPHIC SCANNERS

The aims of this study were to analyze the tone reproduction of photog raphic scanners and to develop simple test procedures. The most import ant arguments proposed are the image noise, image resolution, sensitiv ity of the scanner, and the visual aspect of the images. A good scanne r should show an image noise lower than +/- 0.03 to 0.05 D for a pixel size of 10 mu m and a resolution up to 10 mu m. Furthermore, the dyna mic density range and the fidelity of tone reproduction should be cont rolled The study includes tests of the scanners most commonly used in photogrammetry and in the printing industry, but shows that their effi ciency does not allow them to fully exploit the high image quality of modern aerial photographs.