Improved colour matching technique for fused nighttime imagery with daytime colours

Previously, we presented a method for applying daytime colours to fused nighttime (e.g., intensified and LWIR) imagery (Toet and Hogervorst, Opt.Eng. 51(1), 2012). Our colour mapping not only imparts a natural daylight appearance to multiband nighttime images but also enhances the contrast and visibility of otherwise obscured details. As a...

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...

Colorizing single band intensified nightvision images

We present a method to give single band intensified nightvision imagery a natural day-time color appearance. For input, the method requires a true color RGB source image and a grayscale nightvision target image. The source and target image are both transformed into a perceptually decorrelated color space. In this color space a best matching...

Identification in static luminance and color noise

If images from multiple sources (e.g. from the different bands of a multi-band sensor) are displayed in color, Signal and Noise may appear as luminance and color differences in the image. As a consequence, the perception of color differences may be important for Target Acquisition performance with fused imagery. Luminance and color can be...

Transferring color to single band intensified nightvision images

We present a method to give single band intensified nightvision imagery a natural day-time color appearance. For input, the method requires a true color RGB source image and a grayscale nightvision target image. The source and target image are both transformed into a perceptually decorrelated color space. In this color space a best matching...

A new universal colour image fidelity metric

We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated colour space. The resulting colour image fidelity metric quantifies the distortion of a processed colour image relative to its original version. We evaluated the new colour image fidelity metric through observer experiments in...

A universal color image quality metric

We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality metric through observer experiments in which...

The Effect of Gamma and Chroma on the Perception of Color Images

We present the results of experiments in which we manipulated color images in the CIELAB space by first applying a scaling factor on chroma (C*). After this we applied a gamma transformation (an exponent relating the input to the output) to the luminance (Y) in XYZ space, while keeping the chromaticity values (x, y) constant. The aim of the...

Perceptual evaluation of different image fusion schemes

Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was produced through a pyramid image merging scheme, in...

Image dataset for testing search and detection models

The TNO Human Factors Searchû2 image dataset consists of: a set of 44 high-resolution digital color images of different complex natural scenes, the ground truth corresponding to each of these scenes, and the results of psychophysical experiments on each of these images. The images in the Searchû2 dataset are a subset of a larger set that has...

Multiscale color image enhancement

This paper introduces a multiscale technique to improve the visual appearance of color images. The saturation and luminance components of a color image often contain complementary information. Details of an image that have low luminance contrast are sometimes distinguished from their background by their color saturation. Therefore, color image...