1,721,088 research outputs found
Le moderne tecnologie di compressione delle immagini e la loro applicazione in campo medico
No full textMetodologie di rappresentazione e compressione per volumi biomedici
No full texthttp://www.ing.unibs.it/~signoron/pub/pub.ph
Global registration of large collections of range images with an improved Optimization-on-a-Manifold approach
No full textModelling and Reduction of PSNR Fluctuations in 3D Wavelet Coding
No full textWe study the effects of the quantization of the three-dimensional wavelet transform coefficients, encoded using a 3D zerotree-based compression scheme. The processing of the quantization error operated by the synthesis filter bank actually determines a modulation of the reconstruction error statistics. This effect entails a non-negligible and potentially objectionable PSNR oscillation among adjacent slices of the decoded 3D data-set, which, e.g. in the biomedical field, would typically be used jointly to reach a diagnosis. In particular, we propose a cyclostationary model of the error statistics fluctuations and an experimental validation of the model itself. Moreover some strategies to reduce such oscillation are suggested and evaluate
Diagnostic Compression of Biomedical Volumes
No full textIn this work we deal with lossy compression of biomedical volumes. By force of circumstances, diagnostic compression is bound to a subjective judgment. However, with respect to the algorithms, there is a need to shape the coding methodology so as to highlight beyond compression three important factors: the medical data, the specic usage and the particular end-user. Biomedical volumes may have very dierent characteristics which derive from imaging modality, resolution and voxel aspect ratio. Moreover, volumes are usually viewed slice
by slice on a lightbox, according to dierent cutting direction (typically one of the three voxel axes). We will see why and how these aspects impact on the choice of the coding algorithm and on a possible extension of 2D well known algorithms to more ecient 3D versions. Cross-correlation between reconstruction error and signal is a key aspect to keep into account; we suggest to apply a non uniform quantization to wavelet coefficients in order to reduce slice PSNR variation. Once a good neutral coding for a certain volume is obtained, non uniform quantization can also be made space variant in order to reach more objective quality on Volumes of Diagnostic Interest (VoDI), which in turns can determine the diagnostic quality of the entire data set
Adaptive dilation analysis for wavelet coding with EMDC
No full textThe Embedded Morphological Dilation Coding (EMDC) algorithm, recently proposed by the author of this work, implements a direct coding of the wavelet coefficients significance map that is based on the action of a new kind of multiresolution binary (bit-plane) morphological operator. EMDC actually includes the most part of existing morphological wavelet codecs, it produces a fully progressive bitstream with low complexity and has demonstrated competitive coding performances. A peculiar feature of EMDC is the adaptive and the extended connectivity nature of the morphological analysis of the subband coefficients. In this paper we give a detailed description of this feature and quantify the related performance improvements. We conclude that the considered pattern analysis and coding technique allow an increased reduction of the data redundancy and fills the gap between existing morphological dilation techniques and state-of-the-art wavelet coders
Automatic mapping of uncalibrated pictures on dense 3D point clouds2013 8th International Symposium on Image and Signal Processing and Analysis (ISPA)
No full textVolume Simplification and Segmentation by 3D Connected Operators
No full textPublication in the conference proceedings of EUSIPCO, Toulouse, France, 200
Progressive Medical Image Compression Using a Diagnostic Quality Measure on Regions-of-Interest
Full text linkPublication in the conference proceedings of EUSIPCO, Rhodes, Greece, 199
Selective coding with controlled quality decay for 2D and 3D images in a JPEG2000 framework
No full textThis paper presents some ideas which extend the functionality and the application fields of a spatially selective coding within a JPEG2000
framework. At first, the image quality drop between the Regions of Interest (ROI) and the background (BG) is considered. In a conventional approach, the reconstructed image quality steeply drops along the ROI boundary; however, this effect could be considered or perceived objectionable in some use cases. A simple quality decay management is proposed here, which makes use of concentric ROI with different scaling factors. This allows the technique to be perfectly consistent with the JPEG2000 part 2 ROI definition and description. Another considered issue is the extension of the selective ROI coding to a 3D Volume of Interest coding. This extension is currently under consideration for the part 10 of JPEG2000, JP3D. An easy and effective 2D to 3D extension for the VOI definition and description is proposed here: a VOI is defined by a set composition of ROI generated solids, where ROI are defined along one or more volume cutting direction, and is described by the relative set of ROI parameters. Moreover, the quality decay management can be applied to this extension. The proposed techniques could have a significant impact on the selective coding of medical images and volumes. Image quality issues are very important but very critical factors in that field, which also constitutes the dominant market for 3D applications. Therefore, some experiments are presented on medical images and volumes in order evaluate the benefits of the proposed approaches in terms of diagnostic quality improvement with respect to a conventional ROI coding usage
- …
