Search results for "JPEG"
showing 10 items of 26 documents
An Efficient Hardware implementation of MQ Decoder of JPEG2000
2014
International audience; JPEG2000 is an international standard for still images intended to overcome the shortcomings of the existing JPEG standard. Compared to JPEG image compression techniques, JPEG2000 standard has not only better not only has better compression ratios, but it also offers some exciting features. As it's hard to meet the real-time requirement of image compression systems by software, it is necessary to implement compression system by hardware. The MQ decoder of the JPEG2000 standard is an important bottleneck for real-time applications. In order to meet the real-time requirement we propose in this paper a novel architecture for a MQ decoder with high throughput which is co…
The Anatomy of an Optical Biopsy Semantic Retrieval System
2012
A case-based computer-aided diagnosis system assists physicians and other medical personnel in the interpretation of optical biopsies obtained through confocal laser endomicroscopy. Extraction in CLE images shows promising results on inferring semantic metadata from low-level features. In order to effectively ensure the interoperability with potential third-party applications, the system provides an interface compliant with the recent standards ISO/IEC 15938-12:2008 (MPEG Query Format) and ISO/IEC 24800 (JPEG Search).
Statistical Modeling of Huffman Tables Coding
2005
An innovative algorithm for automatic generation of Huffman coding tables for semantic classes of digital images is presented. Collecting statistics over a large dataset of corresponding images, we generated Huffman tables for three images classes: landscape, portrait and document. Comparisons between the new tables and the JPEG standard coding tables, using also different quality settings, have shown the effectiveness of the proposed strategy in terms of final bit size (e.g. compression ratio).
Yleinen laskenta grafiikkasuorittimilla
2012
Esitellään nykyaikaisten grafiikkasuorittimien rakennetta, toimintaperiaatteita ja tutkitaan OpenCL:ää keinona käyttää niiden laskentakykyä yleisempään laskentaan. Toteutetaan osa JPEG-kuvanpakkausalgoritmia grafiikkasuorittimella OpenCL:n avulla.
Image Compression by 2D Motif Basis
2011
Approaches to image compression and indexing based on extensions to 2D of some of the Lempel-Ziv incremental parsing techniques have been proposed in the recent past. In these approaches, an image is decomposed into a number of patches, consisting each of a square or rectangular solid block. This paper proposes image compression techniques based on patches that are not necessarily solid blocks, but are affected instead by a controlled number of undetermined or don't care pixels. Such patches are chosen from a set of candidate motifs that are extracted in turn from the image 2D motif basis, the latter consisting of a compact set of patterns that result from the autocorrelation of the image w…
A new algorithm for bit rate allocation in JPEG2000 tile encoding
2004
A new algorithm for allocating a given bit rate to different image tiles in the JPEG2000 encoding system is proposed. The algorithm outperforms other approaches commonly used in implementations. The new algorithm is suitable when information content is not equally distributed across the image. It is based on the computation of an index of the information content of each tile. To implement the proposed approach, we modified JasPer, a free software-based JPEG2000 coder implementation (Adams, M.D. and Kossentini, F., Proc. IEEE Int. Conf. on Image Process., vol.2, p.53-6, 2000). The experimentation was carried out on a subset of the JPEG2000 test images. Experimental results are reported, show…
Implementation of JPEG2000 arithmetic decoder using dynamic reconfiguration of FPGA
2005
This paper describes implementation of a part of JPEG2000 algorithm (MQ-Decoder and arithmetic decoder) on a FPGA board using dynamic reconfiguration. Comparison between static and dynamic reconfiguration is presented and new analysis criteria (time performance, logic cost, spatio-temporal efficiency) are defined. MQ-decoder and arithmetic decoder can be classified in the most attractive case for dynamic reconfiguration implementation: applications without parallelism by functions. This implementation is done on an architecture designed to study dynamic reconfiguration of FPGAs: the ARDOISE architecture. The implementation obtained, based on four partial configurations of arithmetic decoder…
Copy-move Forgery Detection via Texture Description
2010
Copy-move forgery is one of the most common type of tampering in digital images. Copy-moves are parts of the image that are copied and pasted onto another part of the same image. Detection methods in general use block-matching methods, which first divide the image into overlapping blocks and then extract features from each block, assuming similar blocks will yield similar features. In this paper we present a block-based approach which exploits texture as feature to be extracted from blocks. Our goal is to study if texture is well suited for the specific application, and to compare performance of several texture descriptors. Tests have been made on both uncompressed and JPEG compressed image…
New techniques for visualization of losses due to image compression in grayscale medical still images
2003
To evaluate the visual influence of irreversible compression on medical images, changes of the images have to be visualized. The authors have explored alternative techniques to be used instead of the usual side-by-side comparison, where the information contained in both images is perceived in a single image, preserving the context between compression errors and image structures. Thus fast and easy comparison can be done. These techniques make use of the human ability to perceive information also in the dimensions of color, space, and time. A study was performed with JPEG-compressed coronary angiographic images. Changes in the resulting images for six compression factors from 7 to 30 were sc…
Kolmogorov superposition theorem for image compression
2012
International audience; The authors present a novel approach for image compression based on an unconventional representation of images. The proposed approach is different from most of the existing techniques in the literature because the compression is not directly performed on the image pixels, but is rather applied to an equivalent monovariate representation of the wavelet-transformed image. More precisely, the authors have considered an adaptation of Kolmogorov superposition theorem proposed by Igelnik and known as the Kolmogorov spline network (KSN), in which the image is approximated by sums and compositions of specific monovariate functions. Using this representation, the authors trad…