• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.337-344
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• 1995

Because of the high energy of the treatment beam, contrast of portal films is very poor. Many image processing techniques have been applied to the portal images but a significant drawback is the loss of definition on the edges of the treatment field. Analysis of this problem shows that it may be remedied by separating the treatment field from the background prior to enhancement and uslng only the pixels within the field boundary in the enhancement procedure. A new edge extraction algorithm for accurate extraction of the radiation field boundary from portal Images has been developed for contrast enhancement of portal images. In this paper, portal image segmentation algorithm based on Sobel filtration, labelling processes and morphological thinning has been presented. This algorithm could automatically search the optimal threshold value which is sensitive to the variation of the type and quality of portal images.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.1
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• pp.81-88
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• 2002

This paper proposes an extraction method which extracts two different thematic maps, which have different line thickness from each other in a raster image that contains the two thematic maps. In the proposed method, the depth of each pixel is calculated according to the amount of pixels in its surrounding neighborhood, and then the thinning is performed. By using depth threshold, two thematic maps are first extracted from the thinning result. There are noise images and skeleton disconnection in the lines of each extracted thematic map. Each thematic map extraction is finally completed after removing the noise images and connecting the disconnected lines. Through the experiment, we showed that the proposed method could be used for the extraction of each thematic map of a raster image which included two thematic maps.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.2
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• pp.96-102
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• 2011

In this study, we performed algorithm development of automatic symptom degree for patient with hallux valgus one of the representative foot disease of morden. And this study proposes an efficient automated technique that is different from the original analog diagnosis for treatment and surgery of hallux valgus using digital image process. And we used X-Ray images of both a normal and a patient with hallux valgus in the procedure. First, we marked the standard angle on the X-Ray image of normal through Overlap & Add technique. Then we created a standard image through thinning filter and roberts filter(edge detection algorithm). Second, we used sobel filter of edge detection algorithm on the X-Ray image of patient. Moreover, we went another overlap & add technique procedure with both normal and patient image that we made. With the output, we projected the display detection image onto the screen. Finally, with the display detection image, we could measure and project the diagnosis angle of hallux valgus. And this confirms that this method is much more practical and applicable for another orthopedics disease than the prior one.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.4
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• pp.23-28
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• 2002

In this paper, we have proposed the hardware architecture which implements the algorithm for retaining the connectivity which prevents the disconnection in the gray-scale image thinning. To extract the skeleton from the image in a real time, it is necessary to examine the connectivity of the skeleton in a real time. The proposed architecture finds the connectivity number in the 4-clock period. The architecture consists of three blocks, PS(Parallel to Serial) Converter and Stare Generator and Ridge Checker. The PS Converter changes the 3$\times$3 gray level image to four sets of image pixels. The State Generator examines the connectivity of the central pixel by searching the data from the PS Converter. The Ridge Checker determines whether the central pixel is on the skeleton or not. The proposed architecture finds the connectivity of the central pixel in a 3$\times$3 gray level image in the 4-clocks. The total circuits are verified by the design tools and operate correctly.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.181-185
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• 2003

Recently, in accordance with supplying high-resolution satellite images which as IKONOS, KVR-1000, and Quick Bird, the use of satellite images have increased in the study which extraction of features from high-resolution satellite images is becoming a new research focus. In this study, using generally involves such as image segmentation, filtering and sobel operator and thinning in image processing for extraction of feature from satellite image. We apply this method to extraction of feature which need to the revision of map from high-resolution IKONOS satellite image data, we verified the capability of extraction of feature and application using satellite image and proposed a plan for the study in the future.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.169-171
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• 2004

This paper propose a new detection method of curve lane using Catmull-Rom spline for recognition various shape of the curve lane. To improve the accracy of lane detection, binarization and thinning process are firstly performed on the input image. Next, features on the curve lane such as curvature and orientation are extracted, and the control points of Catmull-Rom spline are detected to recognize the curve lane. Finally, Computer simulation results are given using a natural test image to show the efficiency of the proposed scheme.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.9
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• pp.1081-1090
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• 1988

A series of procedures using image processing techniques is presented for extracting layout information fast and automatically from chip images. CIF (caltech intermediate form) is chosen for representing such information. First, line-edges are extracted using a line-edge detector. Then, thinning and noise removal procedures follow. Subsequent procedures are vertex extraction and vertex grouping. Finally, CIF is extracted from the coordinates of the grouped vertices. In this paper, the final process is applied to only metal layer. In experiments, this processing scheme is shown to be very effective in extracting CIF.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1984.10a
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• pp.101-103
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• 1984

The proposed seal identification procedure consists of the thresholding smoothing, rotation, thinning, and matching techniques. The weighted map is constructed by ditance weighted correlation CK is computed. The CK is compared with the dicision constant Cs or Cd for the purpose of seal identification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.493-496
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• 2010

This paper proposes an effective hardware scheme for thinning stage processing of a fingerprint identification algorithm based on minutiae with 40% cycle occupation of 32-bit RISC microprocessor. The thinning step is needed to be processed by hardware block, because it is performed repeatedly by processing the same operation using an image window masking method. It can reduce the burden of the system and improve speed. The hardware is implemented by HDL and simulated. The result is compared with a conventional one.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.481-490
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• 2002

Off-line handwritten character recognition is in difficulty of incomplete preprocessing because it has not dynamic information has various handwriting, extreme overlap of the consonant and vowel and many error image of stroke. Consequently off-line handwritten character recognition needs to study about preprocessing of various methods such as binarization and thinning. This paper considers running time of watershed algorithm and the quality of resulting image as preprocessing for off-line handwritten Korean character recognition. So it proposes application of effective watershed algorithm for segmentation of character region and background region in gray level character image and segmentation function for binarization by extracted watershed image. Besides it proposes thinning methods that effectively extracts skeleton through conditional test mask considering routing time and quality of skeleton, estimates efficiency of existing methods and this paper's methods as running time and quality. Average execution time on the previous method was 2.16 second and on this paper method was 1.72 second. We prove that this paper's method removed noise effectively with overlap stroke as compared with the previous method.