The development of a compression algorithm for reduction of the transmission bit rate of 3D integral TV pictures is discussed. The proposed full parallax 3D image compression algorithm takes advantage of the cross cor...
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The development of a compression algorithm for reduction of the transmission bit rate of 3D integral TV pictures is discussed. The proposed full parallax 3D image compression algorithm takes advantage of the cross correlation between the multiple images recorded on a CCD placed behind a directionally selective microlens array as well as the correlation inherent within each image. Tests carried out show that by using a hybrid DPCM/DCT coding scheme to code a still 3D integral TV image, high compression performance can be obtained while retaining all the necessary information to reconstruct a faithful duplicate of the original 3D image. A coding scheme for moving integral 3D images is also described.
This paper describes a method for extracting words, textlines and text blocks by analyzing the spatial configuration of bounding boxes of connected component on a given document image. The basic idea is that connected...
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A segmentation-based hybrid video codec is introduced, able to work with sequences acquired by a moving camera. The global movement of the camera is compensated, allowing a working procedure in the codec closer to the...
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A segmentation-based hybrid video codec is introduced, able to work with sequences acquired by a moving camera. The global movement of the camera is compensated, allowing a working procedure in the codec closer to the case of static background. The segmentation scheme consists of a relaxation algorithm followed by a bottom-up merging procedure. The region contour description is dramatically reduced through forward and backward region based motion estimation and compensation, applied over an image where the camera motion has already been compensated. Structural image information is used to carry out a selective displacement field difference (DFD) coding. Although the encoded bit-rate is highly reduced, the reconstruction of image objects is improved, avoiding characteristic blocking effects.
A new approach for on-line cursive script recognition that combines a letter spotting technique with an island-driven lattice search algorithm is presented. Initially, all plausible letter components within an input p...
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During the MPEG-2 coding of television pictures, buffer overflow occurs in motion-intensive scenes. As a result, time-varying levels of coding distortion are introduced into the video. This study reports on the subjec...
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During the MPEG-2 coding of television pictures, buffer overflow occurs in motion-intensive scenes. As a result, time-varying levels of coding distortion are introduced into the video. This study reports on the subjective effect of such distortion on viewers. Subjects were presented with 30s television test sequences coded using MPEG-2 into 1 and 4 Mbit/s. The ITU-R DSCQS method was used to assess the quality of each 10s section of the 30s sequence and the overall quality. Results obtained confirmed the inadequacy of 10s test sequences for subjective assessment.
The observation that pairs of photometric stereo (PS) images viewed under stereoscope produce an impression of depth which can be almost as striking as that produced by stereoscopic pairs led to the study of photometr...
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The observation that pairs of photometric stereo (PS) images viewed under stereoscope produce an impression of depth which can be almost as striking as that produced by stereoscopic pairs led to the study of photometric stereo as a geometric image-matching process. Thus, the possibility of extracting shape information from the optical flow which results from the change of illumination of PS images was analyzed. It was indicated that, 1) under quite general conditions, the PS optical flow can be related to the spatial derivatives of p and q, and can thus be used for the estimation of surface curvature;and 2) under the assumption that a linear approximation to the reflectance map is appropriate, estimates of the relative-depth function, z(x,y) can also be obtained from such a flow.
Singular Value Decomposition, which has previously been applied to the problem of signal extraction from marine data, Zalloum et al (1), is currently being implemented for land use classification, Danaher et al (2). N...
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Singular Value Decomposition, which has previously been applied to the problem of signal extraction from marine data, Zalloum et al (1), is currently being implemented for land use classification, Danaher et al (2). Neural networks are becoming increasingly popular for the characterisation of multispectral remote sensing data, Benediktsson et al (3). There are a number of significant problems with using ANN as classifiers for this type of data. A comparison of these two procedures is performed and there merits and difficulties discussed. The authors introduce the Levenberg Marquardt technique as an advanced method for finding the global minima during a Backpropagation (BP) training scenario. These techniques are applied to simulated data generated from Landsat TM and SPOT satellite data of the County Wicklow area of Ireland. This data comprises five classes including Sitka spruce and Scots pine.
This paper describes a word segmentation algorithm which is based on the recursive morphological closing transform. The algorithm is trainable for any given document image population and is capable of detecting words ...
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Past research in shape analysis and OCR has often emphasized graph matching techniques. We propose to use matching of graph embeddings because this is what is actually of interest. In this way we obtain faster and sim...
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A method of coding super high definition (SHD) still images based on lattice vector quantisation of wavelet coefficients is proposed. In this coding technique, each block of wavelet coefficients is coded by a series o...
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A method of coding super high definition (SHD) still images based on lattice vector quantisation of wavelet coefficients is proposed. In this coding technique, each block of wavelet coefficients is coded by a series of vectors of decreasing magnitudes, resulting in a successive approximation process. It also exploits the structural similarities among the bands. This provides efficient coding together with the ability to guarantee arbitrary distortion levels for each band, which can be exploited to achieve optimum bit allocation. Conventional image compression techniques such as transform, sub-band and vector quantisation have already been tested for the coding of SHD images. Simulation results show that the proposed method achieves excellent coding performance and it outperforms other SHD image coding methods reported so far by more than 7 dB.
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