Datasets of natural and urban digital photos

These datasets contain photographs from natural and urban scenes, and can be used freely when acknowledging Joris Bleys and Tony Belpaeme.

The nature dataset contains 300 digital or digitised photographs of natural scenes. The images contain a selection of flora and fauna. The images are of different sizes (ranging from 240 by 180 pixels to 1152 by 864 pixels). They were collected from the internet and are available as JPG files. Note that the JPG format tends to reduce the chromatic content by compressing the chromatic u and v channels in the Yuv representation is uses.

The urban dataset contains 278 digital photographs of urban scenes. The images contain scenes from Brussels, taken in October and November of 2003. The images are available as uncompressed TIFF files; the chromatic channels have not been compressed. The photos were made with an Olympus 4000C ZOOM digital camera.

The full dataset can be downloaded as a ZIP-file (328 Mb): http://arti.vub.ac.be/research/colour/data/imagesets.zip

The following figures show a low-res overview of the nature dataset (left) and urban dataset (right).

A histogram of a sample of the CIE L*a*b* values of is shown below. The top three figures are from the urban photographs, the bottom three figures are from the natural dataset. This reconfirms previous observations on the chromatic content of natural scenes, where it was found that natural occurring colours occupy a restricted area of the chromaticity diagram.

These datasets have been used in the following publications:

Belpaeme, Tony and Bleys, Joris (2005) Explaining universal colour categories through a constrained acquisition process. Adaptive Behavior. 13(4):293-310.