• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.565-568
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• 2006

In the luminance and chrominance signal, luminance signal creates gray images, and is capable of making each color component compatible with monochrome system. And color components of luminance and chrominance signals are useful to encode or convert the signal because they have low correlation. Each color signal has low correlation statistically, but they are not independent of one another. Therefore, this paper proposes the watermark inserting algorithm for luminance and chrominance signal in the domain of frequency founded on wavelet, considering the interdependent characteristics of color components. Therefore, it can guarantee the robustness and invisible of digital watermark.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.50-58
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• 2008

In this paper, we propose a color transient improvement (CTI) algorithm based on image fusion to improve the color transient in the television(TV) receiver or in the MPEG decoder. Video image signals are composed of one luminance and two chrominance components, and the chrominance signals have been more band-limited than the luminance signals since the human eyes usually cannot perceive changes in chrominance over small areas. However, nowadays, as the advanced media like high-definition TV(HDTV) is developed, the blurring of color is perceived visually and affects the image quality. The proposed CTI method improves the transient of chrominance signals by exploiting the high-frequency information of the luminance signal. The high-frequency component extracted from the luminance signal is modified by spatially adaptive weights and added to the input chrominance signals. The spatially adaptive weight is estimated to minimize the ${\iota}_2-norm$ of the error between the original and the estimated chrominance signals in a local window. Experimental results with various test images show that the proposed algorithm produces steep and natural color edge transition and the proposed method outperforms conventional algorithms in terms of both visual and numerical criteria.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.211-224
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• 1994

In this paper, a multi-level adaptive intraframe method has been proposed to separate the luminance and chominance components in NTSC composite signal. The control signals are generated by detecting the vertical correlation and transition in the horizontal and diagonal directions. The chrominance component is adaptively processed through vertical and horizontal filters according to the control signals and the luminance component is processed by subtracting the chrominance component from the composite video signal. The several filters have been used at the sampling rate of four times the color subcarrier frequency and computer simulation and SVP(Serial Video Processing) system have been introduced to compare the performance of the conventional methods and that of proposed one.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.1
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• pp.72-80
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• 1988

In this paper, new adaptive interframe filtering methods have been proposed to separate the luminance and chrominance components in NTSC composite signals. In thess methods, the composite signals are adaptivelty processed in three dimensions according to the local change or movement of the picture. For interframe processing, two algorithms have been proposed which adapt three filters in the horizontal, vertical and temporal directions to the magnitude f detection signal dependent upon both the movement and local change of the picture. The three kind of filters have been used at the sampling rate of four times the subcarrier frequency. The various quantitative measures have been introduced to compare the objective performance of the conventional methods and that of proposed ones by computer simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.1946-1953
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• 2006

Because the embedded watermark of luminance component guarantees the extraction of ownership information when the color image is converted to gray scale image, the information of ownership right as to the luminance component is embedded in the luminance-chrominance color space such as YCbCr. Therefore, this paper proposes watermark embedding, extraction and authentication algorithm of color image. which considers the device and performance of multimedia contents service by focusing on the robustness and invisibility of watermark. The color image is converted from RGB color space to YCbCr color space, and then the properties of each component of Y(Luminance), Cb(Color Differences) and Cr(Color Differences) are considered in order to embed, extract and certify multi-level watermark in the frequency domain based on the wavelet. As a result, it can guaranteed the robustness for the JPEG compression and invisibility of watermark for multi-level.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.297-300
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• 2002

In this paper, we propose a post-processing method to reduce the blocking artifacts. We perform the post-processing only in the spatial domain so that it is readily applicable to real-time video decoder. Many approaches proposed so far for deblocking deal with only The luminance signal. but here we propose processing the chrominance signals as well since the low bit rare application where the blocking artifacts are most problematic suffers significantly from the color misalignment caused by blocking artifacts occurring to chrominance data as well. The proposed method is composed of low pass filtering in two steps considering the edge direction. The first step is the IIR low pass filtering in the diagonal direction, and the second step is another IIR low pass filtering in horizontal and vertical directions.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1326-1329
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• 2006

In this paper, we propose a non-linear interpolation of chrominance components based on the property of luminance signals to display color images effectively. The proposed method is more useful, in particular, for the images including stair-typed signal changes around edges. Experimental results show that the proposed method is superior to conventional methods in both objective and subjective performance.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.34-40
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• 1999

In conventional color television systems color edges of highly saturated color pictures are deteriorated because of bandwidth limitation of the color-difference signal. In this paper a modified hue-weighted luminance demodulation method with low noise is proposed for the edge correction. The weighting coefficients are given by ratios of the gadient of color-difference signal to the gradient of band-limited luminance signal. Proposed method is theoretically complete for the 1st order lowpassed color-difference signals and well separated luminance/chrominance signal. Noise reduction technique is also considered because of impulse noise generation in the gradient ratio processing of noisy pictures. In computer simulation with noisy pictures proposed technique gives a visual effect of the bandwidth expansion and detail improvement in highly saturated color edge area.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.159-167
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• 2013

In stereo-view system, variations of target camera position or lighting conditions cause discrepancies on the luminance and chrominance components of stereo views. These discrepancies lead to inaccurate frame view prediction and low quality of 3 D video coding. In this paper, an efficient histogram interval calibration method is proposed for stereo-view coding, so as to compensate for the luminance component of target view. First the proposed method is analyzed by the histogram of the target image frame. Then, it divide two sections of histogram of that frame to correct the color discrepancies. Secondly, each section of the target frame is corrected the luminance component by identify the maximum matching region between the reference frame and the target frame. We have verified our proposed histogram matching method in comparison with the other color correction ones. Experimental results show that it can correct better luminance calibration results of PSNR(Peak Signal to Noise Ratio) and has less computation time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.8 no.4
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• pp.156-163
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• 1983

A composite DPCM system is designed and implemented for the transmission of a NTSC color TV signal over a 44, 736Mbps channel. It is based on an intra-field fourth-order linear predictor and a nonlinear quantizer of five bits. The predictor preserves both the luminance and the chrominance components through one predictor. To accomodate the speed requirement for real time processing, mainly high speed ECL gates and memory devices are used in the hardware implementation. Experimental results show that this composite DPCM system can be applicable for a practical transmission of color TV signal with CATV quality.