nils-herrmann/clean_scirepeval huggingface dataset:
Green Noise Digital Halftoning With Multiscale Error Diffusion

Multiscale error diffusion (MED) is superior to conventional error diffusion algorithms as it can eliminate directional hysteresis completely and possesses a good blue noise characteristic. However, due to its filter design, it is not suitable for systems with poor isolated dot generation and instable dot gain. In this paper, we propose a MED algorithm to produce halftones of desirable green noise characteristics. This algorithm allows one to adjust the desirable cluster size freely through a single parameter and supports a linear relationship between the cluster size and the input gray level. With a close-to-isotropic diffusion filter, the algorithm can effectively remove pattern artifacts, eliminate directional artifacts and preserve original image details. Analysis and simulation results show that it provides better performance in terms of various aspects including dot distribution, anisotropy and output image quality as compared with other conventional green noise error diffusion algorithms.
A robust model generation technique for model-based video coding

In conventional model-based coding schemes, predefined static models are generally used. These models cannot adapt to new situations, and hence, they have to be very specific and cannot be generated from a single generic model even though they are very similar. We present a model-generation technique that can gradually build a model and dynamically modify it according to new video frames scanned. The proposed technique is robust to the object's orientation in the view and can be efficiently implemented with a parallel processing technique. As a result, the proposed technique is more attractive to the practical use of model-based coding techniques in real applications.
Row-oriented multiscale error diffusion technique for digital halftoning

A digital halftoning method is proposed to diffuse error with a more symmetric error distribution by making use of the concept of multiscale error diffusion. The method can improve the diffusion performance by effectively reducing directional hysteresis. The diffusion is row-oriented rather than frame-oriented and hence can reduce the latency and computational effort as compared with conventional multiscale error diffusion schemes. This makes it possible for real-time applications.
Improving JPEG/MPEG coding performance by jointly optimizing both compression and blocking effect elimination

Though post-processing is generally performed in JPEG/MPEG decoders to eliminate the blocking effect appeared in decoded images, few encoders will take care of it during compression. In this paper, we propose to take the post-processing stage into account when encoding an image and make use of it to improve the quality of the reconstructed images both subjectively and objectively. An example is also provided to show how this idea works successfully when classical low-pass filtering is exploited in the post-processing stage.
Realizing super-resolution with a directional anisotropic correlation model

This paper presents a directional anisotropic correlation model for super resolution reconstruction. A local adaptive correlation model is formed by exploiting local edge direction and anisotropic characteristic. For a local region with presence of edge or texture, a directional anisotropic correlation model is suitable to describe the local correlation while the correlation model tends to be more isotropic for a smoother region. A super resolution algorithm is proposed based on the proposed adaptive correlation model. Experiment shows that with the suggested correlation model the proposed algorithm is able to provide a good reconstruction result.
An efficient fractal-based algorithm for image magnification

An efficient image magnification algorithm based on the iterated function system (IFS) is proposed in this paper. Employing the self-similarity property makes it possible to generate images of higher resolution. Our proposed algorithm can maintain not only the high frequency information that preserves the edges, but also effectively remove blocky artifacts from a magnified image. To further improve the quality of the high-resolution images, the error image or residual errors are considered. In addition, our algorithm can combine with other magnification algorithms. Experimental results show that our proposed algorithm can increase the PSNR by 2.60 dB, 2.30 dB and 0.83 dB, on average, when compared to the traditional fractal-based image magnification algorithm, the bicubic spline interpolation method and the recently proposed fractal-based image magnification algorithm (IEUF), respectively. If residual errors are considered, the PSNR of our algorithm can be further increased by about 0.22 dB. When combining our algorithm with IEUF, the PSNR can further improve by 0.4 dB, on average.
A lossless coding scheme for encoding color-indexed video sequences

A new lossless video compression scheme for coding sequences of color-indexed frames is proposed. This scheme handles the frames sequentially. It reduces both the zero-order entropy and the energy of the index map of a specific frame by turning the index map into a new index map each element of which serves as an index to a pixel-dependently reordered version of the palette. Accordingly, a matching coding scheme can be exploited to encode the new index map effectively. A technique similar to the one used in animated GIF is also used to remove the inter-frame redundancy. Simulation results show that the proposed method is superior (in terms of compression ratio) to other state-of-art lossless compression algorithms in coding color-indexed video sequences.
Mixed-radix discrete cosine transform

Presents two new fast discrete cosine transform computation algorithms: a radix-3 and a radix-6 algorithm. These two new algorithms are superior to the conventional radix-3 algorithm as they (i) require less computational complexity in terms of the number of multiplications per point, (ii) provide a wider choice of the sequence length for which the DCT can be realized and, (iii) support the prime factor-decomposed computation algorithm to realize the 2/sup m/3/sup n/-point DCT. Furthermore, a mixed-radix algorithm is also proposed such that an optimal performance can be achieved by applying the proposed radix-3 and radix-6 and the well-developed radix-2 decomposition techniques in a proper sequence.
Regularized restoration of VQ compressed images with constrained least squares approach

In this paper, an iterative algorithm is proposed to restore VQ-encoded images. This algorithm incorporates adaptivity into simple CLS restoration algorithm by weighting every pixel according to its expected derivation from the original. This algorithm is fully compatible with any VQ codec to improve the codec's coding performance. Computer simulations showed that the proposed scheme was superior to other conventional schemes in terms of SNR improvement. Besides, the image quality could also be improved subjectively by reducing the blocking effect.
Producing color-indexed images with scalable color and spatial resolutions

Making the media content to be delivered over the Internet to clients of various capabilities scalable is crucial to improve the efficiency of various involved parties. GIF is one of the primary Web file formats used in Web applications nowadays and hence it is desirable to make them scalable as well. However, as GIF format is purposely designed for supporting clients of limited decoding capability, the scalability should be introduced with only a small increase in decoder complexity and bitstream overhead. This paper presents an algorithm that is able to produce color-indexed images with scalable color and spatial resolutions. Downscaled versions of an color-indexed image can be obtained by just bit-cropping and/or down-sampling the index plane of the image.
Optimizing MPEG-4 coding performance by taking post-processing into account

In this paper, a block-based coding scheme is proposed. Unlike those schemes exploited in a conventional codec, the proposed scheme takes the post-processing scheme to be used in the decoder into account during encoding. An example is also provided in this paper to show how this coding scheme jointly optimizes the compression and the blocking-effect elimination when an MPEG-4 deblocking filter is exploited in the post-processing stage.
Restoration of half-toned color-quantized images using Particle Swarm Optimization with wavelet mutation

Restoration of color-quantized images is rarely addressed in the literature, especially when the images are color-quantized with halftoning. Most existing restoration algorithms are generally inadequate to deal with this problem as they were proposed for restoring noisy blurred images. In this paper, a restoration algorithm based on particle swarm optimization with wavelet mutation (WPSO) is proposed to solve the problem. This algorithm makes a good use of the available color palette and the mechanism of a halftoning process to derive useful a priori information for restoration. Simulation results show that it can improve the quality of a half-toned color-quantized image remarkably in terms of both SNRI and convergence rate. The subjective quality of the restored images can also be improved.
Colour quantization of compressed video sequences based on the estimation of cumulative colour histogram

This paper presents a novel colour quantization algorithm for compressed video data. The proposed algorithm extracts DC coefficients and motion vectors of blocks in a shot to estimate a cumulative colour histogram of the shot and, based on the estimated histogram, design a colour palette for displaying the video sequence in the shot. It significantly reduces the complexity of the generation of a palette by effectively reducing the number of training vectors used in training a palette without sacrificing the quality. The palette obtained can provide a good display quality even if zooming and panning exist in a shot. The experimental results show that the proposed method can achieve a significant SNR improvement as compared with conventional video colour quantization schemes when zooming and panning are encountered in a shot.
Symmetric realization of DCT for multi-dimensional data compression

The row-column approach is widely used for the realization of multi-dimensional DCT due to its simple and flexible structure. This paper proposes a new DCT algorithm which is most suitable for the realization of multi-dimensional DCT with the row-column decomposition technique. By using this new algorithm, the saving in terms of computational complexity is exponentially proportional to the degree of dimension compared with any other 1-D DCT algorithms. On the other hand, this new algorithm can also achieve additional saving in terms of the number of multiplications when the complete DCT realization is not necessary. These two important properties make the algorithm very suitable for the realization of multi-dimensional DCT for image compression.<<ETX>>
A fast two-stage algorithm for realizing matching pursuit

Matching pursuit has proved to be one of the most efficient techniques in various signal coding techniques. However, its computation effort is so tremendous that it may not be affordable in some real-time applications. A two-stage filtering structure for realizing matching pursuit has recently proposed. This paper presents an efficient algorithm for the implementation of the structure. The issues of how to determine the elementary dictionary and approximate a given initial dictionary are also addressed. Simulation results show that the proposed algorithm can achieve a significant improvement in the complexity-distortion performance.
An adaptive model generation technique for model-based video coding

In conventional model-based coding schemes, predefined static models are generally used. These models cannot adapt to new situations and hence they have to be very specific and cannot be generated from a single generic model even though they are very similar. In this paper, we present a model generation technique that can gradually build a model and dynamically modify it according to new video frames scanned. The proposed technique is robust to the object's orientation in the view and can be efficiently implemented with parallel processing technique. As a result, the proposed technique is more attractive to the practical use of model-based coding techniques in real applications.
New 2/sup n/ discrete cosine transform algorithm using recursive filter structure

The discrete cosine transform (DCT) is widely used in digital signal processing. It is always desirable to look for more efficient algorithms for the realization of the DCT. We generalize a formulation for converting a length-2/sup n/ DCT into n groups of equations, then apply a novel technique for its implementation. The sizes of the groups are 2/sup m/, for m=n-1,...,0. While their structures are extremely regular. The realization can then be converted into the simplest recursive filter form, which is of particularly simple for practical implementation. The filter structure is numerically stable, since it involves no division at all.
A row-oriented error diffusion technique for digital halftoning

A digital halftoning method is proposed to diffuse error with a more symmetric error distribution by making use of the concept of multiscale error diffusion. It can improve the diffusion performance by effectively reducing directional hysteresis. The diffusion is row-oriented father than frame-oriented and hence can reduce a lot of computation effort as compared with conventional multiscale error diffusion schemes. This makes it possible for real-time applications.
On the realization of discrete cosine transform using the distributed arithmetic

A unified approach to the realization of forward and inverse discrete cosine transforms is proposed. With this approach, an odd prime length DCT/IDCT with two half-length convolutions can be realized without extra overhead in terms of the number of multiplications. The formulation is most suitable for realization using distributed arithmetic, in which case typical convolvers can be used as the core unit for the hardware implementation of the transforms. Hence, an efficient unified DCT/IDCT chip is proposed to demonstrate the superiority of the formulation. The proposed architecture can easily meet the speed requirement of 14.3 MHz real-time operation with the current 2 mu m CMOS technology.
IT Service Management for Campus Environment-Practical Concerns in Implementation

Adequate definition and adoption of standardized management processes form the foundation to enhance IT service management (ITSM) especially in tally with the arrangement of outsourcing operation management and contracting project development. With the establishment of defacto standard IT infrastructure library (ITIL) for ITSM implementation in these days, management software tools are available in the market. However, proper service management processes shall be developed to align with the existing daily operations workflow, model around ITIL framework, rather than compromising commercial product standard template. This paper first evaluates the effect of ITSM tools in practical adoption in supporting various types of service category in campus environment of technology industries. Experience sharing to address specific concerns in developing customized management process modules for the campus with service outsourcing will be discussed afterwards. Finally, a future work on proactive service impact analysis framework is defined.
Color Demosaicing Using Variance of Color Differences

This paper presents an adaptive demosaicing algorithm. Missing green samples are first estimated based on the variances of the color differences along different edge directions. The missing red and blue components are then estimated based on the interpolated green plane. This algorithm can effectively preserve the details in texture regions and, at the same time, it can significantly reduce the color artifacts. As compared with the latest demosaicing algorithms, the proposed algorithm produces the best average demosaicing performance both objectively and subjectively
A cyclic correlated structure for the realization of discrete cosine transform

The authors propose using the correlated cosine structure (CCS) for the computation of the discrete cosine transform (DCT). This structure has circulant property and is most suitable for the hardware realization. They show that there exists a close relationship between the CCS and the DCT. In such a case, a 2/sup m/ length DCT can be decomposed recursively into shorter length CCS and DCT. This new approach results in very simple and straightforward structure and gives the minimum number of multiplications for its realization.
A novel algorithm for color quantization by 3D diffusion

A novel algorithm for color quantization, called three-dimensional frequency diffusion (3D FD), applies to the histogram of an image based on the principle of error diffusion using a 3D error diffusion filter. With the histogram divided into overlapping cubes, an iterative process is devised to select representative colors from these cubes by a popularity scheme that considers a neighborhood of pixels until a colormap is filled. The algorithm is simple but effective. Results show that images quantized by the proposed algorithm are comparable in quality to other popular algorithms.
Green noise video halftoning

Video halftoning is a technology used to render a video onto a display device that can only display limited number of levels. Conventional video halftoning algorithms produce blue noise video halftones which are prone to flickering. Dedicated deflickering processes are hence required to reduce flickering. These processes share a common approach in which pixels are artificially made stable subject to some quality constraints. Due to the difficulty to control the extent of stability, artifacts caused by overstability such as dirty window effect, subtle motion and residual shadow are easily found in video halftones. In this paper, we suggest producing green noise video halftones instead of blue noise video halftones. By doing so, we can effectively reduce flickering and eliminate artifacts caused by overstability from the root simultaneously.
A constrained error diffusion method to shape quantization noise in backlight dimming

Backlight dimming is a powerful method to reduce power consumption of LED-LC displays. However, there remains a problem to preserve perceived quality while reducing backlight luminance. Distortion of backlight dimming can be classified to three types: clipping, leakage and quantization. The former two distortions have been widely discussed in the literature, but the quantization noise is generally ignored. This paper presents a LC compensation framework which exploits error diffusion to shape the quantization noise. Simulation results show that the proposed approach is efficient to achieve the goal.
Eliminating blocking artifacts in halftoning-based block truncation coding

Block Truncation Coding (BTC) is an effective lossy image coding technique that enjoys both high efficiency and low complexity especially when halftoning techniques are employed to shape the noise spectrum of its output. However, due to its block-based nature, blocking artifacts are commonly found in the coding outputs. In this work, a real-time halftoning-based BTC algorithm is proposed to solve this problem by eliminating the cause of blocking artifacts while maintaining a complexity comparable to the best state-of-the-art halftoning-based BTC algorithm. Both objective and subjective comparisons demonstrate the visual quality improvement in its encoding outputs.
Optimizing the Error Diffusion Filter for Blue Noise Halftoning With Multiscale Error Diffusion

A good halftoning output should bear a blue noise characteristic contributed by isotropically-distributed isolated dots. Multiscale error diffusion (MED) algorithms try to achieve this by exploiting radially symmetric and noncausal error diffusion filters to guarantee spatial homogeneity. In this brief, an optimized diffusion filter is suggested to make the diffusion close to isotropic. When it is used with MED, the resulting output has a nearly ideal blue noise characteristic.
Enhanced integrated gradient and its applications to color demosaicing

In this paper, an effective decision-based demosaicing algorithm for Bayer images is presented. An enhanced edge-sensing measure called enhanced integrated gradient (EIG) is exploited to guide the interpolation along the edges. This measure improves the recently proposed integrated gradient (IG) and hence can support more gradient information from various color intensity and color difference planes under the directional compatibility constraint. An adaptive green plane enhancement which works with the EIG is also proposed to further improve the efficiency of the algorithm.
An Adaptive Color Filter Array Interpolation Algorithm for Digital Camera

In this paper, an adaptive color filter array (CFA) interpolation method is presented. By examining the edge levels and the variance of color difference along different edge directions, the missing green samples are first estimated. The missing red and blue samples are then estimated based on the interpolated green plane. This algorithm can effectively preserve the details as well as significantly reduce the color artifacts. As compared with some current state-of-art methods, the proposed algorithm provides outperformed results in terms of both subjective and objective image quality measures.
Novel formulation and realisation of discrete cosine transform using distributed arithmetic

A new algorithm is introduced such that one can convert an odd prime length, N, discrete cosine transform (DCT) into two (N-1)/2 length cyclic correlations. This formulation enables realization of the DCT by using distributed arithmetic and it also results in an extremely regular structure which is most suitable for VLSI realization. The proposed algorithm can be realized efficiently and easily by dedicated hardware or gate array technology. The structure of the hardware required is so simple that it involves only memory and adders. This can achieve a high performance DCT chip at a minimum cost and development time. An example is given to show the feasibility and the structural regularity of the algorithm.<<ETX>>
Algorithm for p/sup m/-length discrete cosine transform

A novel algorithm is introduced that makes it possible to realize a discrete cosine transform (DCT) by correlations. A p/sup 2/-length DCT can be realized through four (p-1)/2-length and two (p-1)p/2-length cyclic correlations with a cost of N-1 multiplications. This formulation is potentially useful for the realization of the DCT using VLSI techniques, especially if the distributed arithmetic technique is used.<<ETX>>
An Efficient Combined Demosaicing and Zooming Algorithm for Digital Camera

Color demosaicing and digital zooming are common processes in digital cameras and they often employ similar interpolation concepts based on the information extracted from the raw sensor data. Realizing them independently is not efficient as separate extraction processes are required. It may also cause inconsistent utilization of the raw sensor data in different stages. This paper presents a low-complexity combined algorithm which directly extracts edge information from raw sensor data and exploits it consistently and efficiently in both demosaicing and zooming. The proposed algorithm can produce zoomed full-color images and zoomed CFA images with outstanding performance as compared with conventional approaches.