Welcome to the download page for the All Natural Image Database (ANID).
Here we offer our collection of natural images for download. The image database was used in
 Drewes, J., Trommershaeuser, J. & Gegenfurtner, K.R.,
(2011). "Parallel visual search and rapid animal detection in natural scenes". Journal of
All images are square, of 1600x1600 or higher resolution, and show exactly one animal in the center quadrant.
These images were selected from the original Tuebingen image database, available at
The database comes in two parts, the images themselves and corresponding mask images.
There are 355 images in the download archive, 294 of which were used in .
For the 294 images used in , we are also providing mask overlays.
These overlays have the same resolution and base filename as the corresponding images, and are stored in Matlab .MAT file format.
The overlays mark the position of the animal in the image on a pixel-by-pixel basis. Any pixel can have one of three values:
0 = background
1 = animal
2 = head of the animal
We provide these images free of charge to the scientific community and interested third parties, for non-profit and academic use.
If you wish to utilize the images and/or masks in your own research, please cite  as the source reference for this database.
We also politely ask that you notify us via email to ANID (at) jandrewes (dot) de. You may also use this address to ask questions.
DFG Grant TR 528 / 1-4 (J. Drewes and J. Trommershaeuser).
DFG Grant Ge 879/7 (K. Gegenfurtner).
DFG Wi 2103/1 and Ge 879/6 (F. Wichmann and K. Gegenfurtner).