In this paper, we present a practical system for enhancing the quality of Low Dynamic Range (LDR) videos using High Dynamic Range (HDR) background images. Our technique relies on the assumption that the HDR information is static in the video footage. This assumption can be valid in many scenarios where moving subjects are the main focus of the footage and do not have to interact with moving lig...

We present Giant Metrewave Radio Telescope 21-cm HI observations towards a sample of compact radio sources behind galaxy groups, to search for cool HI. The results – from high dynamic range spectra for 8 lines-of-sight through 7 galaxy groups – do not show any evidence for absorption by cool HI. At a resolution of 20 km s −1 , the optical depth upper limits obtained were between 0.0075 and 0.03...

This paper introduces a new approach for optimum auto exposure (AE) based on the high-dynamic-range histogram (HDH) of a scene. The exposure control is optimal in terms of recorded information of the scene. The advantages over AE based on mean values of images will be shown as well as a proof of concept implementation and results. Futhermore possible extensions to this approach are discussed. T...

High dynamic range image (HDR) is widely used since it is capable of capturing more fine information. However, problems remain in its display. A good rendering of HDR color images requires careful treatment of both the brightness and chromaticity information. In this work, we first prove that the global logarithmic mapping of the R, G, B channels may result in desaturation. We then propose an i...

The visualization of SAR images involves the mapping of high dynamic range amplitude values to gray levels for lower dynamic range display devices. This dynamic range reduction process determines the visibility of details in the displayed result. It is therefore an important part of SAR visualization systems. The problem of dynamic range reduction for SAR images is related to the tone mapping p...

Tone mapping of high dynamic range (HDR) images for realistic display is a commonly studied. However, scientific visualization of HDR image for analysis of scene luminance has much less attention. In this paper, we have presented and implemented a simple approach for the reproduction and visualization of the color information in HDR images. We attempt several simple color visualizing functions,...

The dynamic range is a ratio between the maximum and minimum physical measures. Its definition depends on what the dynamic range refers to. For a scene, dynamic range is the ratio between the brightest and darkest parts of the scene. For a camera, dynamic range is the ratio of saturation to noise. More specifically, ratio of the intensity that just saturates the camera to the intensity that jus...