1,721,229 research outputs found
Effective color space representation for wavelet based compression of HDR images
No full textEffective color image and video coding is usually exploited coupling a compression method with the most suitable color space representation. This work extends a previously proposed high dynamic range (HDR) image coding method, which combines a logarithmic color adaptation module with a JPEG2000 codec. Here we propose to change the original preprocessing stage with a more adequate one, based on the LogLuv color space representation, in order to take fully advantage of wavelet based coding. The experimental comparisons confirm that the proposed method improves the compression performances and simplify the overall coding scheme
Raw image Encoding Based on Polynomial Approximation
No full textIn this paper, we propose a coding algorithm for raw images with high dynamic ranges. Our encoder has two layers. In the first layer, 24 bit low dynamic range image is encoded by a conventional codec, and then the ratio image that represents the difference between the decoded 24 bit image and the raw image is encoded in the second layer. Experiments shows compression efficiency is significantly improved by taking an inverse tone mapping into account
Two-Layer Coding Algorithm For High Dynamic Range Images based on Intensity Compensation
No full textA two-layer coding algorithm for high dynamic range images is discussed. In the first layer, a low dynamic range image is encoded by a conventional codec, and then the residual information that represents the difference between an original and the decoded images in the first layer is encoded in the second layer, which realizes compatibility with conventional image file formats. Our method utilizes the approximation of an inverse tone mapping function that reduces the high dynamic range to a displayable range. Our algorithm significantly improves a compression performance, compared to conventional methods
JPEG Compatible Raw Image Coding Based on Polynomial Tone Mapping
No full textIn this paper, we propose a coding method for camera raw images with high dynamic ranges. Our encoder has two layers. In the first layer, 24 bit low dynamic range image is encoded by a conventional codec, and then the residual image that represents the difference between the raw image and its approximation is encoded in the second layer. The approximation is derived by a polynomial fitting. The main advantage of this approach is that applying the polynomial model reduces the correlation between the raw and 24 bit images, which increases coding efficiency. Experiments shows compression efficiency is significantly improved by taking an inverse tone mapping into account
Effective color space representation for compression of HDR images with JPEG2000
No full textISO/IEC JTC1/SC29/WG1 N4192. Apr. 2007. San Jose - CA, USA
ACQUISITION AND ENCODING OF HIGH DYNAMIC RANGE IMAGES USING INVERSE TONE MAPPING
No full textA two layer coding algorithm for high dynamic range images is discussed. In the first layer, a low dynamic range image is encoded by a conventional codec, and then the residual information that represents the difference between an original and the decoded images in the first layer is encoded in the second layer, which realizes compatibility with conventional image file formats. Our method utilizes the approximation of an inverse tone mapping function that reduces the high dynamic range to a displayable range. Our algorithm significantly improves a compression performance, compared to conventional methods
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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