Learn More
Honeybees turn their thorax and thus their flight motor to change direction or to fly sideways. If the bee's head were fixed to its thorax, such movements would have great impact on vision. Head movements independent of thorax orientation can stabilize gaze and thus play an important and active role in shaping the structure of the visual input the animal(More)
We present a fast and efficient homing algorithm based on Fourier transformed panoramic images. By continuously comparing Fourier coefficients calculated from the current view with coefficients representing the goal location, a mobile robot is able to find its way back to known locations. No prior knowledge about the orientation with respect to the goal(More)
Panoramic image differences can be used for view-based homing under natural outdoor conditions, because they increase smoothly with distance from a reference location (Zeil et al., J Opt Soc Am A 20(3):450-469, 2003). The particular shape, slope and depth of such image difference functions (IDFs) recorded at any one place, however, depend on a number of(More)
Two recent studies testing navigation of rats in swimming pools have posed problems for any account of the use of purely geometric properties of space in navigation (M. Graham, M. A. Good, A. McGregor, & J. M. Pearce, 2006; J. M. Pearce, M. A. Good, P. M. Jones, & A. McGregor, 2004). The authors simulated 1 experiment from each study in a virtual reality(More)
We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their(More)
The responses of disparity-tuned neurons computed according to the energy model are used for reliable vergence control of a stereo camera head and for disparity estimation. Adjustment of symmetric ver-gence is driven by minimization of global image disparity resulting in greatly reduced residual disparities. To estimate disparities, cell activities of four(More)
We investigate the influence of the mirror shape on the imaging quality of catadioptric sensors. For axially symmetrical mirrors we calculate the locations of the virtual image points considering incident quasi-parallel light rays. Using second order approximations, we give analytical expressions for the two limiting surfaces of this " virtual image zone ".(More)