Efficient contrast enhancement through log-power histogram modification

A simple power-logarithm histogram modification operator is proposed to enhance digital image contrast. First a logarithm operator reduces the effect of spikes and transforms the image histogram into a smoothed one that approximates a uniform histogram while retaining the relative size ordering of the original bins. Then a power operator...

Fast natural color mapping for night-time imagery

We present a new method to render multi-band night-time imagery (images from sensors whose sensitive range does not necessarily coincide with the visual part of the electromagnetic spectrum, e.g. image intensifiers, thermal camera's) in natural daytime colors. The color mapping is derived from the combination of a multi-band image and a...

A model to predict the sound reflection from forests

A model is presented to predict the reflection of sound at forest edges. A single tree is modelled as a vertical cylinder. For the reflection at a cylinder an analytical solution is given based on the theory of scattering of spherical waves. The entire forest is represented by a line of cylinders placed along the forest edge. The spacing between...

TRICLOBS portable triband color lowlight observation system

We present the design and first test results of the TRICLOBS (TRI-band Color Low-light OBServation) system The TRICLOBS is an all-day all-weather surveillance and navigation tool. Its sensor suite consists of two digital image intensifiers (Photonis ICU's) and an uncooled longwave infrared microbolometer (XenICS Gobi 384). The night vision...

Portable real-time color night vision

We developed a simple and fast lookup-table based method to derive and apply natural daylight colors to multi-band night-time images. The method deploys an optimal color transformation derived from a set of samples taken from a daytime color reference image. The colors in the resulting colorized multiband night-time images closely resemble the...

Method for applying daytime colors to nighttime imagery in realtime

We present a fast and efficient method to derive and apply natural colors to nighttime imagery from multiband sensors. The color mapping is derived from the combination of a multiband image and a corresponding natural color reference image. The mapping optimizes the match between the multiband image and the reference image, and yields a...