N-tert-Butyl-3-hydr­oxy-5-androstene-17-carboxamide monohydrate

In the title compound, C24H39NO2·H2O, the A and C rings of the pregnolene derivative sterol adopt chair conformations, with the B ring in a flattened chair conformation and the five-membered ring in an envelope conformation twisted about the C/D ring junction. The N-tert-butyl­carboxamide substituent is equatorial. The 3β-hydr­oxy H atom and one H atom of the water mol­ecule are disordered over two positions with equal occupancies. In the crystal structure, O—H⋯O hydrogen bonds between the 3β-hydr­oxy groups of neighbouring mol­ecules form dimers in the bc plane and these dimers are stacked along the a axis by additional O—H⋯O hydrogen bonds involving the water mol­ecules. The steric effect of the bulky tert-butyl substituent in the carboxamide chain precludes hydrogen-bond formation by the N—H group

Blind Correction of Lateral Chromatic Aberration in Raw Bayer Data

Chromatic aberration is an error that occurs in color images due to the fact that camera lenses refract the light of different wavelengths in different angles. The common approach today to correct the error is to use a lookup table for each camera-lens combination, e.g., as in Adobe PhotoShop Lightroom or DxO Optics Pro. In this paper, we propose a method that corrects the chromatic aberration error without any priot knowledge of the camera-lens combination, and does the correction already on the bayer data, i.e., before the Raw image data is interpolated to an RGB image. We evaluate our method in comparison to DxO Optics Pro, a state-of-the-art tool based on lookup tables, using 25 test images and the variance of the color differences (VCD) metric. The results show that our blind method has a similar error correction performance as DxO Optics Pro, but without prior knowledge of the camera-lens setup. CCBYNCNDopen access</p

Error-bounded lossy compression of floating-point color buffers using quadtree decomposition

In this paper, we present a new color buffer compression algorithm for floating-point buffers. It can operate in either an approximate (lossy) mode or in an exact (lossless) mode. The approximate mode is error-bounded and the amount of introduced accumulated error is controlled via a few parameters. The core of the algorithm lies in an efficient representation and color space transform, followed by a hierarchical quadtree decomposition, and then hierarchical prediction and Golomb-Rice encoding. We believe this is the first lossy compression algorithm for floating-point buffers, and our results indicate significantly reduced color buffer bandwidths and negligible visible artifacts

Exact and Error-Bounded Approximate Color Buffer Compression and Decompression

In this paper, we first present a survey of existing color buffer compression algorithms. After that, we introduce a new scheme based on an exactly reversible color transform, simple prediction, and Golomb-Rice encoding. In addition to this, we introduce an error control mechanism, which can be used for approximate (lossy) color buffer compression. In this way, the introduced error is kept under strict control. To the best of our knowledge, this has not been explored before in the literature. Our results indicate superior compression ratios compared to existing algorithms, and we believe that approximate compression can be important for mobile GPU

Comparing Two Generations of Embedded GPUs Running a Feature Detection Algorithm

Graphics processing units (GPUs) in embedded mobile platforms are reaching performance levels where they may be useful for computer vision applications. We compare two generations of embedded GPUs for mobile devices when run- ning a state-of-the-art feature detection algorithm, i.e., Harris- Hessian/FREAK. We compare architectural differences, execu- tion time, temperature, and frequency on Sony Xperia Z3 and Sony Xperia XZ mobile devices. Our results indicate that the performance soon is sufficient for real-time feature detection, the GPUs have no temperature problems, and support for large work-groups is important.BigData@BTH - Scalable resource-efficient systems for big data analyticsEASE - Embedded Applications Software Engineerin

Comparing Two Generations of Embedded GPUs Running a Feature Detection Algorithm

Graphics processing units (GPUs) in embedded mobile platforms are reaching performance levels where they may be useful for computer vision applications. We compare two generations of embedded GPUs for mobile devices when run- ning a state-of-the-art feature detection algorithm, i.e., Harris- Hessian/FREAK. We compare architectural differences, execu- tion time, temperature, and frequency on Sony Xperia Z3 and Sony Xperia XZ mobile devices. Our results indicate that the performance soon is sufficient for real-time feature detection, the GPUs have no temperature problems, and support for large work-groups is important.BigData@BTH - Scalable resource-efficient systems for big data analyticsEASE - Embedded Applications Software Engineerin

Texture compression of light maps using smooth profile functions

Light maps have long been a popular technique for visually rich real-time rendering in games. They typically contain smooth color gradients which current low bit rate texture compression techniques, such as DXT1 and ETC2, do not handle well. The application writer must therefore choose between doubling the bit rate by choosing a codec such as BC7, or accept the compression artifacts, neither of which is desirable. The situation is aggravated by the recent popularity of radiosity normal maps, where three light maps plus a normal map are used for each surface. We present a new texture compression algorithm targeting smoothly varying textures, such as the light maps used in radiosity normal mapping. On high-resolution light map data from real games, the proposed method shows quality improvements of 0.7 dB in PSNR over ETC2, and 2.8 dB over DXT1, for the same bit rate. As a side effect, our codec can also compress many standard images (not light maps) with better quality than DXT1/ETC2