In this paper we present a low frequency image adaptive watermarking scheme. Using the GenLOT transform for image decomposition in the watermarking scheme we obtain higher energy compaction in the low frequency coeffi...
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ISBN:
(纸本)0780375270
In this paper we present a low frequency image adaptive watermarking scheme. Using the GenLOT transform for image decomposition in the watermarking scheme we obtain higher energy compaction in the low frequency coefficients. As a result, we improve the robustness of operations that remove high frequency components. In order to embed the watermark with minimum loss in image fidelity, a visual mask based on local image characteristics, such as textures and edges, is incorporated in the watermarking algorithm. Experimental results show that the proposed scheme is robust against DCT and DWT based compression and common imageprocessing operations.
The characterization of mottle, both for imprinted substrates and printed material, is becoming an increasingly important metric to predict and measure the quality of hardcopy output. Currently there are three methods...
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ISBN:
(纸本)0892082380
The characterization of mottle, both for imprinted substrates and printed material, is becoming an increasingly important metric to predict and measure the quality of hardcopy output. Currently there are three methods commonly in use: visual examination and comparison to some standard samples;use of a camera or scanner and imageprocessing software to evaluate mottle using a method based on the ISO/IEC 13660 standard algorithm;and quantitative analysis with a vision system that allows tailoring of the algorithm to separate the components of the mottle artifacts. Mottle is a defect that can certainly degrade the perception of the quality of a print. Perception is dependent on several factors, including spatial. frequency (size), contrast, sharpness, and viewing conditions (including illumination and distance). Therefore, mottle should be characterized taking these factors into consideration. If elimination or minimization of mottle is desired in order to improve the quality of the end product, the detection of mottle is necessary but not sufficient. Quantitative analysis provides the data to identify components comprising the mottle, allowing causal relationships to be established. This paper will detail two methods of quantifying mottle. One uses variable high pass spatial filters to separate the frequency components of the variation in the uniformity. The other characterizes the actual non-uniformity as cluster-type defects and allows quantification by size, contrast, and morphology.
In this paper we propose an unsupervised anchorperson detection algorithm from an MPEG coded TV program recorded for many hours. In order to extract news topic presentation shots, we employed several visual features s...
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ISBN:
(纸本)0780373006
In this paper we propose an unsupervised anchorperson detection algorithm from an MPEG coded TV program recorded for many hours. In order to extract news topic presentation shots, we employed several visual features such as motion, face, caption, and clothing on an MPEG DC image domain. In the experiment, it has been shown that news topics were successfully extracted from a recorded TV program for 24 hours.
Extending automatic speech recognition (ASR) to the visual modality has been shown to greatly increase recognition accuracy and improve system robustness over purely acoustic systems, especially in acoustically hostil...
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Extending automatic speech recognition (ASR) to the visual modality has been shown to greatly increase recognition accuracy and improve system robustness over purely acoustic systems, especially in acoustically hostile environments. An important aspect of designing such systems is how to incorporate the visual component into the acoustic speech recognizer to achieve optimal performance. In this paper, we investigate methods of integrating the audio and visual modalities within HMM-based classification models. We examine existing integration schemes and propose the use of a coupled hidden Markov model (CHMM) to exploit audio-visual interaction. Our experimental results demonstrate that the CHMM consistently outperforms other integration models for a large range of acoustic noise levels and suggest that it better captures temporal correlations between the two streams of information.
Scale-space representation has been extensively studied in the computer vision community for analyzing image structures at different scales. This paper borrows and develops useful mathematical tools from scale-space t...
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ISBN:
(纸本)0769514774
Scale-space representation has been extensively studied in the computer vision community for analyzing image structures at different scales. This paper borrows and develops useful mathematical tools from scale-space theory to facilitate the task of image compression. Instead of compressing the original image directly, we propose to compress its scale-space representation obtained by the forward diffusion with a Gaussian kernel at the chosen scale. The major contribution of this work is a novel solution to the ill-posed inverse diffusion problem. We analytically derive a nonlinear filter to deblur Gaussian blurring for ID ideal step edges. The generalized 2D edge enhancing filter only requires the knowledge of local minimum/maximum and preserves the geometric constraint of edges. When combined with a standard wavelet-based image coder, the forward and inverse diffusion can be viewed as a pair of pre-processing and post-processing stages used to select and preserve important image features at the given bit rate. Experiment results have shown that the proposed diffusion-based techniques can dramatically improve the visual quality of reconstructed images at low bit rate (below 0.25bpp).
Fine-Granularity-Scalability (FGS) has recently been standardized in MPEG-4 due to its flexibility in adapting in real-time to Internet bandwidth variations and its resilience to packet-losses. However, the flexibilit...
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ISBN:
(纸本)0780376226
Fine-Granularity-Scalability (FGS) has recently been standardized in MPEG-4 due to its flexibility in adapting in real-time to Internet bandwidth variations and its resilience to packet-losses. However, the flexibility and robustness come at the expense of degrading video quality when compared with non-scalable MPEG-4 video coding at a given bit-rate. To reduce this visual quality penalty at low and medium bit-rates, the "Frequency Weighting" (FW) method has been standardized that allows the prioritized transmission of "low frequency" DCT coefficients. In this paper, we propose a novel scene-characteristic-dependent adaptive FW method aimed at improving the visual quality of FGS. After a thorough analysis of the FGS (i.e., SNR) residual signal at various bit-rates, we conclude that for an improved subjective quality, different FW matrices should be used to improve the FGS visual quality depending on the video sequence characteristics. Subsequently, a simple classification mechanism is developed that categorizes the video sequences based on their brightness, motion and texture activity in four distinct classes, each using a different FW matrix. For each class, the appropriate FW matrix was determined a priori based on the differences of the residual signals for two representative single-layer bit-rates. This adaptive FW (AFW) method has been subjectively evaluated and shows a clear improvement in visual quality compared with non-frequency weighted or non-adaptive frequency weighted sequences.
A method is given for visually assessing the cluster tendency of a set of Objects O = {o(l),...,o(n)} when they are represented either as object vectors or by numerical pairwise dissimilarity values. The objects are r...
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ISBN:
(纸本)0780372786
A method is given for visually assessing the cluster tendency of a set of Objects O = {o(l),...,o(n)} when they are represented either as object vectors or by numerical pairwise dissimilarity values. The objects are reordered and the reordered matrix of pair wise object dissimilarities is displayed as an intensity image. Clusters are indicated by dark blocks of pixels along the diagonal.
This Volume 4736 of the conference proceedings contains 26 papers. Topics discussed include visual information processing, classification, remote sensing and other applications, information theory, restoration and rec...
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This Volume 4736 of the conference proceedings contains 26 papers. Topics discussed include visual information processing, classification, remote sensing and other applications, information theory, restoration and reconstruction, image coding and compression.
Lossy multimedia transmissions need efficient channel coding schemes. We propose here a specific classification of JPEG2000 data for progressive quality image transmission. We deduce that hierarchical channel coding s...
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Color is one of the main visual cues and has been frequently used in imageprocessing, analysis and retrieval. The extraction of high-level color descriptors is an increasingly important problem, as these descriptions...
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ISBN:
(纸本)0780376226
Color is one of the main visual cues and has been frequently used in imageprocessing, analysis and retrieval. The extraction of high-level color descriptors is an increasingly important problem, as these descriptions often provide link to image content. When combined with image segmentation color naming can be used to select objects by color, describe the appearance of the image and even generate semantic annotations. For example, regions labeled as light blue and strong green may represent sky and grass, vivid colors are typically found in man-made objects, and modifiers such as brownish, grayish and dark convey the impression of the atmosphere in the scene. This paper presents a computational model for color categorization, naming and extraction of color composition. In this work we start from the National Bureau of Standards' recommendation for color names [4], and through subjective experiments develop our color vocabulary and syntax. Next, to attach the color name to an arbitrary input color, we design a perceptually based color naming metric. Finally, we extend the method and develop a scheme for extracting the color composition of a complex image. The algorithm follows the relevant neurophysiological findings and studies on human color categorization. In testing the method the known color regions in different color spaces were identified accurately, the color names assigned to randomly selected colors agreed with human judgments, and the color composition extracted from natural images was consistent with human observations.
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