• Journal of the Institute of Convergence Signal Processing
• /
• v.14 no.1
• /
• pp.6-12
• /
• 2013

Mammography is the most common technique for the early detection of breast cancer. To diagnose correctly and treat of breast cancer efficiently, many image enhancement methods have been developed. This paper presents a nonlinear image enhancement method for the enhancement of digital mammogram. The proposed method is composed of a nonlinear function for brightness improvement and a nonlinear filter for contrast enhancement. The nonlinear function improves the brightness of dark area and extends the dynamic range of bright area, and the nonlinear filter efficiently enhances the specific regions and objects of the mammogram. The final enhanced image was obtained by combining the processed image with the nonlinear function and the filtered image with the nonlinear filter. The proposed nonlinear image enhancement method was confirmed the enhanced performance comparing with other existing methods.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.6
• /
• pp.442-453
• /
• 2020

Underwater color images suffer from low visibility and color cast effects caused by light attenuation by water and floating particles. This study applied single image enhancement techniques to enhance the quality of underwater images and compared their performance with real underwater images taken in Korean waters. Dark channel prior (DCP), gradient transform, image fusion, and generative adversarial networks (GAN), such as cycleGAN and underwater GAN (UGAN), were considered for single image enhancement. Their performance was evaluated in terms of underwater image quality measure, underwater color image quality evaluation, gray-world assumption, and blur metric. The DCP saturated the underwater images to a specific greenish or bluish color tone and reduced the brightness of the background signal. The gradient transform method with two transmission maps were sensitive to the light source and highlighted the region exposed to light. Although image fusion enabled reasonable color correction, the object details were lost due to the last fusion step. CycleGAN corrected overall color tone relatively well but generated artifacts in the background. UGAN showed good visual quality and obtained the highest scores against all figures of merit (FOMs) by compensating for the colors and visibility compared to the other single enhancement methods.

• MALSORI
• /
• no.48
• /
• pp.81-91
• /
• 2003

In this paper, we propose a speech recognition method based on independent component analysis (ICA) and spectral enhancement techniques. While ICA tris to separate speech signal from noisy speech using multiple channels, some noise remains by its algorithmic limitations. Spectral enhancement techniques can compensate for lack of ICA's signal separation ability. From the speech recognition experiments with instantaneous and convolved mixing environments, we show that the proposed approach gives much improved recognition accuracies than conventional methods.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.514-517
• /
• 1998

This paper proposed a symmetric feedback current enhancement circuit with 1.5V power supply to design a 3$^{rd}$ order butterworth low pass filter. The proposed filter designed on 0.8.mu.m CMOS n-well double poly/double metal process simulated in HSPICE composed of the 3dB frequency enhancement circuit and the unity-gain frequency enhancement circuit. The simulation result on the design filter shows the badnwith of 25MHz, phase of 92.6 .deg. and power consumption of 0.3mW..

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.913-914
• /
• 2008

This paper presents a method of adaptive image enhancement with dynamic range compression and contrast enhancement. The dynamic range compression is to adaptively enhance the dark area using illumination component of DCT compression block. The contrast enhancement is to modify the image contrast using retinex theory that uses the HVS properties. The block artifacts and other noises, caused by processing in the compression domain, were removed by after processing.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.521-524
• /
• 1999

In spite of advances in image resolution and film contrast, check screen/film mammography remains one of diagnostic imaging modality where the image interpretation is very difficult. For the enhancement of film mammography, in this paper, dyadic wavelet transform is introduced. An unsharp masking technique is proposed and performed in wavelet domain. In addition, simple nonlinear enhancement and a denosing stage that preserves edges using wavelet shrinkage are computed into this technique. In this paper. we propose a new method for the gain setting of nonlinear enhancement and show result and comparison.

• Journal of Multimedia Information System
• /
• v.4 no.2
• /
• pp.89-92
• /
• 2017

This paper investigates simple gray level image enhancement technique based on Genetic Algorithms and Local Statistics. The task of GA is to adapt the parameters of local sliding masks over pixels, finding out the best parameters preserving the brightness and possibly preventing the creation of intensity artifacts in the local area of images. The algorithm is controlled by GA as to enhance the contrast and details in the images automatically according to an object fitness criterion. Results obtained in terms of subjective and objective evaluations, show the plausibility of the method suggested here.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.5-8
• /
• 2002

The paper handles a skin tone enhancement within digitalized images, which is based on human favorite skin color. To archive a human-favorite skin tone area, lots of observers are participated in visual experiments. The statistical result of the visual experiment was reflected in a proposed skin tone enhancement algorithm and gives more reasonable human-friendly skin color reproduction on a display device. This research was accomplished to implement in our DTV related application.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.275-278
• /
• 2002

Sharpness enhancement, which strengthen the edge(high frequency) of image, is widely studied for image processing research area. In this paper, psychophysical experiment is conducted by the 20 observers with simple linear unsharp masking for sharpness enhancement. The experimental results extracted using z-score analysis and linear regression suggests observer preferable sharpness enhancement method for digital television.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.794-797
• /
• 2007

We have developed the adaptive contrast ratio enhancement algorithm for mobile LCD. This algorithm aims at effective contrast ratio enhancement with minimizing degeneration of color and white balance. It also is very simple to fit mobile LCD system.