The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Chi-wah Wong - One of the best experts on this subject based on the ideXlab platform.
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automatic white balancing using Luminance Component and standard deviation of rgb Components image preprocessing
International Conference on Acoustics Speech and Signal Processing, 2004Co-Authors: Hong-kwai Lam, Chi-wah WongAbstract:Automatic white balancing is an essential image preprocessing Component in consumer digital still cameras, and it can greatly improve the final image quality of the captured image. In this paper, a novel automatic white balancing algorithm based on both the Luminance Component and standard deviation of RGB Components of the pre-captured image is proposed. A light source model for evaluation of an automatic white balancing is also described. The simulation results indicate that the proposed algorithm can improve the final image quality of the captured image.
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Automatic white balancing using Luminance Component and standard deviation of RGB Components
2004Co-Authors: Hong-kwai Lam, Chi-wah WongAbstract:Automatic white balancing is an essential image pre-processing Component in consumer digital still cameras, and it can greatly improve the final image quality of the captured image. In this paper, a novel automatic white balancing algorithm based on both Luminance Component and standard deviation of RGB Components of the precaptured image is proposed. A light source model for evaluation of an automatic white balancing is also described. The simulation results indicate that the proposed algorithm can improve the final image quality of the captured image.
Hong-kwai Lam - One of the best experts on this subject based on the ideXlab platform.
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automatic white balancing using Luminance Component and standard deviation of rgb Components image preprocessing
International Conference on Acoustics Speech and Signal Processing, 2004Co-Authors: Hong-kwai Lam, Chi-wah WongAbstract:Automatic white balancing is an essential image preprocessing Component in consumer digital still cameras, and it can greatly improve the final image quality of the captured image. In this paper, a novel automatic white balancing algorithm based on both the Luminance Component and standard deviation of RGB Components of the pre-captured image is proposed. A light source model for evaluation of an automatic white balancing is also described. The simulation results indicate that the proposed algorithm can improve the final image quality of the captured image.
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Automatic white balancing using Luminance Component and standard deviation of RGB Components
2004Co-Authors: Hong-kwai Lam, Chi-wah WongAbstract:Automatic white balancing is an essential image pre-processing Component in consumer digital still cameras, and it can greatly improve the final image quality of the captured image. In this paper, a novel automatic white balancing algorithm based on both Luminance Component and standard deviation of RGB Components of the precaptured image is proposed. A light source model for evaluation of an automatic white balancing is also described. The simulation results indicate that the proposed algorithm can improve the final image quality of the captured image.
Hongying Yang - One of the best experts on this subject based on the ideXlab platform.
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a robust blind color image watermarking in quaternion fourier transform domain
Journal of Systems and Software, 2013Co-Authors: Xiangyang Wang, Chunpeng Wang, Hongying YangAbstract:Highlights? To embed the digital watermark in quaternion Fourier transform domain, which improves the robustness against color attacks. ? To correct the watermarked image by LS-SVM classification, which improve the robustness against geometrical distortions. ? To modify the symmetric quaternion Fourier transform coefficients, which improve the watermark imperceptibility. Most of the existing color image watermarking schemes were designed to mark the image Luminance Component only, which have some disadvantages: (i) they are sensitive to color attacks because of ignoring the correlation between different color channels, (ii) they are always not robust to geometric distortions for neglecting the watermark desynchronization. It is a challenging work to design a robust color image watermarking scheme. Based on quaternion Fourier transform and least squares support vector machine (LS-SVM), we propose a robust blind color image watermarking in quaternion Fourier transform domain, which has good visual quality. Firstly, the original color image is divided into color image blocks. Then, the fast quaternion Fourier transform is performed on the color image block. Finally, the digital watermark is embedded into original color image by adaptively modulating the real quaternion Fourier transform coefficients of color image block. For watermark decoding, the LS-SVM correction with pseudo-Zernike moments is utilized. Experimental results show that the proposed color image watermarking is not only robust against common image processing operations such as filtering, JPEG compression, histogram equalization, and image blurring, but also robust against the geometrical distortions.
Xiangwei Zheng - One of the best experts on this subject based on the ideXlab platform.
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an optimized digital watermarking algorithm in wavelet domain based on differential evolution for color image
PLOS ONE, 2018Co-Authors: Xiangwei ZhengAbstract:In this paper, a new color watermarking algorithm based on differential evolution is proposed. A color host image is first converted from RGB space to YIQ space, which is more suitable for the human visual system. Then, apply three-level discrete wavelet transformation to Luminance Component Y and generate four different frequency sub-bands. After that, perform singular value decomposition on these sub-bands. In the watermark embedding process, apply discrete wavelet transformation to a watermark image after the scrambling encryption processing. Our new algorithm uses differential evolution algorithm with adaptive optimization to choose the right scaling factors. Experimental results show that the proposed algorithm has a better performance in terms of invisibility and robustness.
Jeffrey J. Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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color image enhancement using spatially adaptive saturation feedback
International Conference on Image Processing, 1997Co-Authors: B A Thomas, Robin N Strickland, Jeffrey J. RodriguezAbstract:One way of enhancing color image contrast is to feed back high-frequency spatial information from the saturation Component into the Luminance Component. A new algorithm, which uses a spatially variant measure of salience, is presented. This method offers key improvements to a previous saturation feedback technique. Experimental results confirm that improved color image enhancement is achieved.
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3 d histogram modification of color images
International Conference on Image Processing, 1996Co-Authors: P A Mlsna, Jeffrey J. Rodriguez, Qiang Zhang, Jeffrey J. RodriguezAbstract:While histogram modification has traditionally been used for the enhancement of color images, it has usually been restricted to processing the Luminance Component and, in some cases, the saturation. Reducing the problem's dimensionality in this manner generally sacrifices the ability to make full use of the color space gamut. Presented here are two novel color image contrast enhancement approaches which operate in three dimensions and aim for full gamut utilization. One is an extension of the histogram explosion algorithm to operate in CIELUV color space, intended to produce perceptually improved results compared to the original RGB method. The other is a new and very efficient recursive method, "histogram decimation," whose output is roughly similar to that of the RGB histogram explosion algorithm. Both algorithms are briefly discussed along with their major characteristics. A direct comparison follows, based on processing a set of standard test images. The performance analysis quantitatively compares the computation time and the mean-squared error in the cdf vs. an ideal, uniform distribution.
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High-resolution histogram modification of color images
Graphical Models and Image Processing, 1995Co-Authors: Jeffrey J. Rodriguez, Christopher C. Yang, Jeffrey J. Rodriguez, Christopher C. YangAbstract:Abstract For color images, histogram modification is usually applied to the quantized Luminance Component. However, the Luminance quantization error can be significantly magnified by the transformation function, leading to distortion in the processed image. The propagation of the quantization error is analyzed theoretically to determine the worst-case error, The relationship between the number of Luminance quantization levels and the output quantization error is derived. Experimental results with histogram equalization demonstrate that the use of a higher resolution histogram leads to reduced distortion as well as a "flatter" output histogram.
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Efficient Luminance and saturation processing techniques for bypassing color coordinate transformations
1995 IEEE International Conference on Systems Man and Cybernetics. Intelligent Systems for the 21st Century, 1Co-Authors: Christopher C. Yang, Jeffrey J. RodriguezAbstract:In many applications of color image processing, only modification of the Luminance Component is desired. However, the commonly used coordinate systems, such as HSI, LHS, and YIQ, are not perceptually orthogonal; that is, Luminance modification can cause perceptual shifts in the hue and saturation. In this paper, the authors present a theoretical analysis of this phenomenon. Efficient techniques are developed for bypassing the costly coordinate transformations when only the Luminance or only the saturation is to be modified. Experimental results using histogram equalization support the theoretical analysis.
