• IEIE Transactions on Smart Processing and Computing
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• v.6 no.3
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• pp.168-174
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• 2017

Videos recorded on surveillance cameras or by car black boxes at night have distorted images due to illumination variation. Therefore, it is difficult to analyze morphological characteristics of objects, and it is limiting to use such distorted images as evidence in traffic accidents. Image restoration is performed by amplifying the brightness of nighttime images using linearized gamma correction to increase their contrast (which destroys visual information) and by minimizing degradation factors caused by irregular traveling.

• Journal of Korea Multimedia Society
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• v.20 no.9
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• pp.1481-1490
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• 2017

This paper presents an image quality enhancement algorithm for dark image acquired under poor lighting condition. Various retinex algorithms which are human perception-based image processing methods were proposed to solve this problem. Although MSR(Multi-Scale Retinex) among these algorithm works well under most lighting condition, it shows color degradation because their separate nonlinear processing of RGB color channels. To compensate for the loss of the color, MSRCR(Multi-Scale Retinex with Color Restoration) was proposed. However, it requires high computational load and has additional parameters that need to be adjusted according to input image. In order to overcome this problem, a new retinex algorithm based on MSR is proposed in this paper. The proposed method consists of V channel MSR, saturation correction, and separate contrast enhancement process. Experimental results show that the subjective and objective image quality of the proposed method better than those of the conventional methods.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1455-1460
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• 1992

Anomalous drainage of the right superior vena cava into the left atrium is a very rare congenital cardiac anomaly. Recently a patient with this venous anomaly was surgically corrected and forms the basis of this report. Patient findings were as follows: The patient has no other symptom but cyanosis which prompted cardiac evaluation Chest PA and electrocariogram were usual. Cross-sectional echocardiogram showed normally connected heart without intracardiac defect, Inferior vena cava drained normally into right atrium and coronary sinus was not dilated. Contrast, given into the right atrium, appeared in the left atrium This rare venous anomaly was confirmed by surgery. Surgical correction consisted of division of superior vena cava above the junction of left atrium and reanastomosis into right atrial appendage. Postoperative digital subtracion angiography confirmed the successful repair. She has doing well for 6months since operation. Systemic venous anomalies without intracardiac defect are very rare. However this anomalies should be considered in the differential diagnosis of cyanosis. The successfully corrected case is reported and literature is reviewed.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.4
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• pp.249-255
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• 2014

We present a simple method to watermark three-dimensional (3D) triangular meshes that have been generated from the depth data of the Kinect sensor. In contrast to previous methods, which maintain the shape of 3D triangular meshes and decide the embedding place, requiring calculations of vertices and their neighbors, our method is based on selecting one of the coordinate axes. To maintain shape, we use discrete wavelet transform and constant regularization. We know that the watermarking system needs the information to be embedded; we used a text to provide that information. We used geometry attacks such as rotation, scales, and translation, to test the performance of this watermarking system. Performance parameters in this paper include the vertices error rate (VER) and bit error rate (BER). The results from the VER and BER indicate that using a correction term before the extraction process makes our system robust to geometry attacks.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.111-117
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• 2006

This paper describes the design principles and methods of electronic processor for thermal imager with 320$\times$240 staring array infrared detector. For the detector's nonuniformity correction and excellent image quality, we have designed the multi-point correction method using the defocusing technique of the optics. And to enhance the image of low contrast and improve the detection capability, the new technique of histogram processing has been designed. Through these image processing techniques, we have developed the high quality thermal imager and acquired a satisfactory thermal image. The result of MRTD(Minimum Resolvable Temperature Difference) is $0.1^{\circ}C$ at 4cycles/mard.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.444-449
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• 2010

The PID control to the monitor color correction was applied. Converted Gamma LUT was applied to the video card. Color and brightness information from the PID controller was used as control inputs. Color and brightness information from a calibrated monitor is measured again. Then, the difference between the preset values for the PID controller was compensated by the feedback. The software measured by color meter was used for color and brightness information. All of the monitor does not measure the color and brightness was measured by sampling. The color and brightness from the monitor were measured not by complete enumeration but by sampling. In the experiment, the original image was displayed on the same monitor as well as two other brands, and then, Gamma and Contrast were measured and compared.

• Journal of Korea Multimedia Society
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• v.18 no.9
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• pp.1027-1038
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• 2015

For last several decades, the color correction methods have been proposed for HDR(high dynamic range) images. However, color distortion problems take place after correcting the colors such as halos, dominant color as well known. Accordingly, this article presents a novel approach in which the method consists of tone-mapping method and cone response function. In the proposed method, the tone mapping method is used to improve the contrast in the given HDR image based on chromatic and achromatic based on the CIEXYZ tristimulus value, expressed in c/m². The cone response function is used to deal with mismatch between corrected image and displayed image as well as to estimate various human visual effects based on the CMCAT2000 color appearance model. The experimental results show that the proposed method yields better performance of color correction over the conventional method in subjective and quantitative quality, and color reproduction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.49-54
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• 2007

Flow analysis in a turbine cascade by Euler or Navier-Stokes equation gives relatively accurate solution, however, those method require large computer memory or computing time. on contrast, the panel method， which is applied to incompressible and inviscid flow, provides fast and reasonal solution but the compressibility correction is required for a high air velocity case. In this paper, the compressibility corrected panel method was applied in order to find velocity distribution on turbine blades. Results showed that the calculated velocity in a turbine cascade by the compressibility corrected panel method gave good agreement with experimental results or the solution by finite volume method for compressible flow.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.1
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• pp.23-28
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• 2008

Flow analysis in a turbine cascade by Euler or Navier-Stokes equation gives relatively accurate solution, however, those method require large computer memory or computing time. On contrast, the panel method, which is applied to incompressible and inviscid flow, provides fast and reasonal solution but the compressibility correction is required for a high air velocity case. In this paper, the compressibility corrected panel method was applied in order to find velocity distribution on turbine blades. Results showed that the calculated velocity in a turbine cascade by the compressibility corrected panel method gave good agreement with the solution by finite volume method for compressible flow.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.33-43
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• 2006

This paper proposes a method to extract coronary arteries effectively in the angiography, In general. DSA(Digital Subtraction Angiography) is a well-established technique for the visualization of coronary arteries, DSA involves the subtraction of a mask image, an image of a heart before the injection of contrast medium, from a live image, However, this technique is sensitive to the movement of background and can cause wrong detection due to the variance of background intensity between two images. Therefore, this paper solves the structural problem resulted from background movement by selecting an image which has the least difference of movement through the similarity analysis of background texture, and it extracts only the blood vessels effectively through local intensity correction of the selected images, Experimental results show that the proposed method has the lower false-detection rate and higher accuracy rate than existing methods.