• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.29 no.2
• /
• pp.417-422
• /
• 1999

Purpose : The aim of this study was to assess the validity of standard deviation of gray scale histogram in digital subtraction radiography as a test parameter for superimposition error. Materials and Methods : Twenty periapical radiographs were used as baseline images and they were copied to exclude the influence of exposure geomety and contrast differences. These subsequent images were linearly displaced by 0.1-0.5 mm in the x-. y- and xy-directions, rotated by 0.5-3° and distorted by angular contraction of 1-5° in x- and y-axis before subtraction. The standard deviations of gray levels in the subtraction images were obtained and paired t-tests were performed. Pearson correlation coefficients(r) were calculated between the standard deviations and the superimposition errors. Results : Linear displacement showed high correlation coefficients of 0.997, 0.997 and 0.995 in x-. y- and xy-axis respectively. Statistically significant different standard deviation existed among all linearly displaced groups(p<0.05). Distortion showed relatively low correlation coefficients of 0.982 and 0.959 in x- and y-axis. The standard deviations between the two distortion groups were statistically significant different(p<0.05). Conclusion : Standard deviation of gray level distribution in digital subtraction images is satisfactory but not perfect similarity measure to assess the superimposition errors.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.10C
• /
• pp.629-634
• /
• 2011

Empty space in the parking lot of the parking space to analyze the effective use of technology and transportation may be useful in the jungle, However, conventional analytical methods impractical parking space or need a fast processing speed. In this paper, real-time parking, so parking monitoring methods for detection is proposed. Gray-level images using the proposed method to determine whether the parking and the parking space was used to analyze. To verify the performance of the proposed method in an outdoor parking lot 129 video capture and analysis of experimental results in 98.5% of the parking space, parking space, the success of the proposed method was proved to be effective in the analysis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.2
• /
• pp.493-497
• /
• 2012

This study was conducted to retrospectively evaluate the pattern of contrast enhancement with SonoVue on gray-scale ultrasonography of hepatic angiomyolipoma (HAML). Imaging features of 33 pathologically proven HAML lesions in 33 patients who underwent baseline ultrasound and contrast-enhanced ultrasonography (CEUS) were assessed retrospectively. All lesions were enhanced in the arterial phase and showed whole-tumor filling in. Thirty-two of 33 (97%) lesions showed early positive enhancement in the arterial phase. Twenty-three of these exhibited isoechoic or hyperechoic features in the portal phase. HAML demonstrate characteristic manifestations with SonoVue-enhanced real-time gray-scale ultrasonography.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.11 no.6
• /
• pp.454-458
• /
• 2001

Based on a fuzzy system representation of gray scale images, we derive and edge detection algorithm whose convolution kernel is different from the known kernels such as those of Robert's Prewitt's or Sobel's gradient. Our fuzzy system representation is an exact representation of the bicubic spline function which represents the gray scale image approximately. Hence the fuzzy system is a continuous function and it provides a natural way to define the gradient and the Laplacian operator. We show that the gradient at grid points can be evaluated by taking the convolution of the image with a 3$\times$3 kernel. We also that our gradient coupled with the approximate value of the continuous function generates an edge detection method which creates edge images clearer than those by other methods. A few examples of applying our methods are included.

• Journal of Veterinary Clinics
• /
• v.23 no.3
• /
• pp.258-262
• /
• 2006

This study was performed to evaluate the usefulness of gray-scale and power Doppler ultrasonography, and to compare with radiography for detection of the repairing in experimentally induced bone defects in dogs. In 4 adult beagle dogs bilateral bone defects were created in 8 canine femurs as sized as 5 mm diameter. Mean detection time of the ultrasonographic endosteal callus formations(mean $14.25{\pm}2.31$ days) was significantly shorter than that of the radiographic opacity chanees(mean $23.50{\pm}2.27$ days) in the defected region. Mean time of the neovascularizd flow signal(mean $6.00{\pm}3.59$ days) from the power Doppler ultrasonographic examination was significantly shorter than that of gray-scale ultrasonographic findings. With these results, gray-scale ultransonography and power Doppler ultrasonography can be used for an early detection modality for bone healing.

• Journal of the Institute of Convergence Signal Processing
• /
• v.12 no.3
• /
• pp.169-175
• /
• 2011

In this paper, an automatic scoring system of the OMR answer sheet is implemented using Gray Scale and image segmentation method. The proposed method was used to extract the OMR data on multiple-choice answer sheet from captured image. In addition, On-line scoring system is developed and implemented to mark the short-answer type on the reverse side. Therefore, teachers can mark the short-answer type for anytime and anywhere within the available time. There were many advantages to mark of the multiple-choice answer sheet without additional OMR reader. In the future, the grading of short-answer type will be more efficient if it were performed by using an automatic scoring system based on image processing.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.6
• /
• pp.1-7
• /
• 2004

The rapid growth of digital media and communication networks has created an urgent need for self-contained data identification methods to create adequate intellectual property right(IPR) protection technology. In this paper we propose a new watermarking method that could embed the gray-scale watermark logo in low frequency coefficients of discrete wavelet transform(DWT) domain as the marking space by using our Linear Bit-eXpansion(LBX) interleaving of gray-scale watermark, to use lots of watermark information without distortion of watermarked image quality and particularly to be robust against attack which could remove a part of image. Experimental results demonstrated the high robustness in particular against attacks such as image cropping and rotation which could remove a part of image.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.4 no.2
• /
• pp.155-160
• /
• 2004

In this paper, we describe the results of a study on the edge enhancement of X-ray images by using their fuzzy system representation. A set of gray scale X-ray images was generated using the EGS4 computer code. An aluminum plate or a lead plate with three parallel strips taken out has been used as the object with the thickness and the width of the plate, and the gap between the two strips varied. We started with a comparative study on a set of the fuzzy sets for their applicability as the input fuzzy sets for the fuzzy system representation of the gray scale images. Then we describe how the fuzzy system is used to sharpen the edges. Our algorithm is based on adding the magnitude of the gradient not to the pixel value of concern but rather to the nearest neighboring pixel in the direction of the gradient. We show that this algorithm is better in maintaining the spatial resolution of the original image after the edge enhancement.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.4
• /
• pp.63-69
• /
• 2012

This paper describes novel scheme of a gray scale capacitive fingerprint image for high-accuracy capacitive sensor chip. The typical gray scale image scheme used a DAC of big size layout or charge-pump circuit of non-volatile memory with high power consumption and complexity by a global clock signal. A modified capacitive detection circuit of charge sharing scheme is proposed, which uses DLC(down literal circuit) based on a neuron MOS(vMOS) and analog simple multiplexor. The detection circuit is designed and simulated in 3.3V, $0.35{\mu}m$ standard CMOS process. Because the proposed circuit does not need a comparator and peripheral circuits, a pixel layout size can be reduced and the image resolution can be improved.

• Fashion & Textile Research Journal
• /
• v.8 no.3
• /
• pp.343-348
• /
• 2006

This study aims to attain gray tone dyed goods by using tannin that is contained in green tea. Tannin is given general name of polyphenol, which has a characteristic that bonds with protein and it is used for food preservative that protects against bacteria, as well as its purpose of black tone dye for silk treatment that has been processed since its early ages. In particular, as tannin reacts with all kinds of metallic mordant and changes to various colors, when tannin acid is combined with iron, it becomes tannin steel and produces gray tone color. Tannin that is contained in green tea is condensed tannins and its structure does not hydrolyze, thus having flavan type structure. In order to find the suitable condition for processing tannin, UV-Vis part absorption spectrum of green tea tannin, dye ability based on temperature and time, reflection rate based on concentration, color changes based on acid treatment and alkali treatment, changes on surface based on concentration or metal mordant condition, and lightfastness were measured. Maximum absorption wavelength (${\lambda}_{max}$) of green tea tannin was at around 273nm, while strong absorption was also observed at below 350 nm. Dye ability of green tea tannin is done more easily on silk rather than cellulose fibers such as cotton, while the optimum condition for dyeing was observed to be at $60^{\circ}C$, for 20 minutes. As a result of acid treatment, the color of dye material consisted highly of gray tones and showed overall gray tone with the combined color of yellow and red after the alkali treatment. While it was observed that as dye concentration and metal mordant concentration increased, the color changed at counter-clockwise direction on the Y-scale of Munsell's scale of colors. Additionally, lightfastness was more on a normal fading.