In this paper, we present a simple and fast inverse half toning algorithm, targeted at reconstructing half toned images generated using dispersed-dot ordered dithering algorithms. the proposed algorithm uses a simple ...
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In this paper, we present a simple and fast inverse half toning algorithm, targeted at reconstructing half toned images generated using dispersed-dot ordered dithering algorithms. the proposed algorithm uses a simple set of linear filters combined with a stochastic model in order to predictthe best intensity values for the binary image pixels. the algorithm produces images with a better perceptual quality than the available algorithms in the literature, preserving most of the fine details of the original gray-level image. It has a high performance, which can be further improved withthe use of parallelization techniques.
We propose a memory-efficient method that computes persistent homology for 3D gray-scale images. the basic idea is to compute the persistence of the induced Morse-Smale complex. Since in practice this complex is much ...
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We propose a memory-efficient method that computes persistent homology for 3D gray-scale images. the basic idea is to compute the persistence of the induced Morse-Smale complex. Since in practice this complex is much smaller than the input data, significantly less memory is required for the subsequent computations. We propose a novel algorithm that efficiently extracts the Morse-Smale complex based on algorithms from discrete Morse theory. the proposed algorithm is thereby optimal with a computational complexity of O(n2). the persistence is then computed using the Morse-Smale complex by applying an existing algorithm with a good practical running time. We demonstrate that our method allows for the computation of persistent homology for large data on commodity hardware.
the detection of QR codes, a type of 2D barcode, as described in the literature consists merely in the determination of the boundaries of the symbol region in images obtained withthe specific intent of highlighting t...
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the detection of QR codes, a type of 2D barcode, as described in the literature consists merely in the determination of the boundaries of the symbol region in images obtained withthe specific intent of highlighting the symbol. However, many important applications such as those related with accessibility technologies or robotics, depends on first detecting the presence of a barcode in an environment. We employ Viola-Jones rapid object detection framework to address the problem of finding QR codes in arbitrarily acquired images. this framework provides an efficient way to focus the detection process in promising regions of the image and a very fast feature calculation approach for pattern classification. An extensive study of variations in the parameters of the framework for detecting finder patterns, present in three corners of every QR code, was carried out. Detection accuracy superior to 90%, with controlled number of false positives, is achieved. We also propose a post-processing algorithm that aggregates the results of the first step and decides if the detected finder patterns are part of QR code symbols. this two-step processing is done in real time.
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