Current Issue : October - December Volume : 2012 Issue Number : 4 Articles : 5 Articles
This paper presents a real-time processing platform for high-definition stereo video. The system is capable to\r\nprocess stereo video streams at resolutions up to 1, 920 Ã?â?? 1, 080 at 30 frames per second (1080p30). In the hybrid\r\nFPGA-GPU-CPU system, a high-density FPGA is used not only to perform the low-level image processing tasks such\r\nas color interpolation and cross-image color correction, but also to carry out radial undistortion, image rectification,\r\nand disparity estimation. We show how the corresponding algorithms can be implemented very efficiently in\r\nprogrammable hardware, relieving the GPU from the burden of these tasks. Our FPGA implementation results are\r\ncompared with corresponding GPU implementations and with other implementations reported in the literature...
The objective of this paper is to implement image inpainting technique using Heat Equation and Perona-Malik Equation and compare the results. Image Inpainting is a technique of modifying an image in an undetectable form. Its most often used to repair an image, although it can easily be used to remove unwanted objects. The modification of images in a way that is non-detectable for an observer who does not know the original image is a practice as old as artistic creation itself. An effective technique for image inpainting has been developed based on partial differential equation (PDE).The heat equation is an important partial differential equation which describes the distribution of heat. Instead of solving the problem in frequency domain, this rather new approach evaluates images in time domain. The basic concept starts from the impression of diffusion as a physical process and draws an analogy between the image inpainting process and the diffusion. Images can be comparable to heat, fluid, and gas which spontaneously move from the area of high concentration to the area of lower concentration. The PDEs operate in much the same way that trained restorers do: They propagate information from the structure around a hole into the hole to fill it in. We have implemented image inpainting technique using PDEs like Heat Equation and Perona-Malik Equation and compared generated results....
Most of the image processing techniques have been first proposed and developed on small size images and\r\nprogressively applied to larger and larger data sets resulting from new sensors and application requirements. In\r\ngeosciences, digital cameras and remote sensing images can be used to monitor glaciers and to measure their\r\nsurface velocity by different techniques. However, the image size and the number of acquisitions to be processed\r\nto analyze time series become a critical issue to derive displacement fields by the conventional correlation\r\ntechnique. In this paper, a mathematical optimization of the classical normalized cross-correlation and its\r\nimplementation are described to overcome the computation time and window size limitations. The proposed\r\nimplementation is performed with a specific memory management to avoid most of the temporary result recomputations.\r\nThe performances of the software resulting from this optimization are assessed by computing the\r\ncorrelation between optical images of a serac fall, and between Synthetic Aperture Radar (SAR) images of Alpine\r\nglaciers. The optical images are acquired by a digital camera installed near the ArgentiÃ?¨re glacier (Chamonix,\r\nFrance) and the SAR images are acquired by the high resolution TerraSAR-X satellite over the Mont-Blanc area. The\r\nresults illustrate the potential of this implementation to derive dense displacement fields with a computational\r\ntime compatible with the camera images acquired every 2 h and with the size of the TerraSAR-X scenes covering\r\n30 Ã?â?? 50 km2....
Quarter-pel (q-pel) motion compensation (MC) is one of the features of H.264/AVC that aids in attaining a much\r\nbetter compression factor than what was possible in preceding standards. The better performance however also\r\nbrings higher requirements for computational complexity and memory access. This article describes a novel data\r\nstorage and the associated addressing scheme, together with the system architecture and FPGA implementation of\r\nH.264 q-pel MC. The proposed architecture is not only suitable for any H.264 standard block size, but also for\r\nstreams with different image sizes and frame rates. The hardware implementation of a stand alone H.264 q-pel MC\r\non FPGA has shown speeds between 95.9 fps for HD1080p frames, 229 fps for HD 720p and between 2502 and\r\n12623 fps for CIF and QCIF formats....
Many vision applications require high-accuracy dense disparity maps in real time. Due to the complexity of the\r\nmatching process, most real-time stereo applications rely on local algorithms in the disparity computation. These\r\nlocal algorithms generally suffer from matching ambiguities as it is difficult to find appropriate support for each\r\npixel. Recent research shows that algorithms using adaptive cost aggregation approach greatly improve the quality\r\nof disparity map. Unfortunately, although these improvements are excellent, they are obtained at the expense of\r\nhigh computational. This article presents a hardware implementation for speeding up these methods. With\r\nhardware friendly approximation, we demonstrate the feasibility of implementing this expensive computational\r\ntask on hardware to achieve real-time performance. The entire stereo vision system, includes rectification, stereo\r\nmatching, and disparity refinement, is realized using a single field programmable gate array. The highly parallelized\r\npipeline structure makes system be capable to achieve 51 frames per second for 640 Ã?â?? 480 stereo images. Finally,\r\nthe success of accuracy improvement is demonstrated on the Middlebury dataset, as well as tests on real scene...
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