Authors

Ing. Martin Zukal, Ing. Jiří Mekyska, Ing. Petr Číka, Ph.D., prof. Ing. Zdeněk Smékal, CSc.

Download

It is possible to download the database here.

Publication to be cited

ZUKAL, M.; MEKYSKA, J.; ČÍKA, P.; SMÉKAL, Z. Interest Points as a Focus Measure in Multi-Spectral Imaging. Radioengineering, 2013, vol. 22, no. 1, pp. 68-81. ISSN: 1210-2512.

Terms of use

This database is freely available. In case of any publications based on this database please cite a paper mentioned above.

Description

This database consists of 7 objects acquired in visible, near-infrared and thermal spectrum. Each subject is captured in a different focus position so that the database can be used for a development of auto-focus algorithms. A total amount of pictures is 420.

The pictures acquired in visible spectrum are divided into 7 sets, while each set contains 12. There are included these objects (see the picture below): headphones, keyboard, keys, loudspeaker, mixer, sunglasses and guitar.

The images in the database of images in the visual spectrum were acquired using Nikon D80 camera with 50 mm f/1.8D AF Nikkor lens. We moved manually the focusing ring in 5 mm steps. We are aware of rather coarse step, but since we are more interested in images in NIR and TH spectrum we did not strive to refine the step. The scene was lit with Fomei photographic lights and softboxes. No additional lighting was required therefore we did not use flash light.

The pictures acquired in near-infrared spectrum are divided into 7 sets, while each set contains 21. There are included these objects (see the picture below): building, car, corridor, head, keyboard, office desk and pens.

All images in the database of infrared images were captured with Canon EOS 350D camera with Canon EF-S 18-55 mm, f/3.5-5.6 lens. The camera was adjusted to capture the EM radiation in NIR spectrum by removing the infrared filter before the CMOS image sensor. We mounted a B+W 093 infrared filter on the lens. This filter blocks all visible light and allows only infrared light above 850 nm to pass. The cut wavelength was measured using VARIAN CARRY 50 UV-VI spectrophotometer. We moved manually the focusing ring in 1 mm steps in this experiment which resulted in 21 images in each set. We used the built-in flash to light the indoor scenes. The outdoor scenes were shot without additional lighting.

The pictures acquired in thermal spectrum are divided into 7 sets, while each set contains 27. There are included these objects (see the picture below): building, circuit breaker, circuit, car engine, printer, server and tube.

The thermal image database was acquired by a thermal camera FLIR SC660. This camera is equipped with an uncooled detector and has a spectral sensitivity range from 7.5 to 13 m. It provides image resolution: 640×480 px; optical field/min. focus distance: 45×34 / 0.2 m; thermal sensitivity: 45 mK at 30 celsius degrees and spatial resolution: 0.65 mrad. More information about this camera can be found in datasheet.