• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.5
• /
• pp.135-143
• /
• 2000

The vision system is easy to use the exclusive use as a independent computer system but it is not much popularization by reason of expensive and difficult to adapt to the various fields, because it is easy to the existed computer system, the price is cheap and also it can use to the various measurement purpose which user wanted and programed. The measurement method of the vehicle axle casing nut welding part is that measure the value of the welding part to adapt the actual operation program from using the ratio between the actual length of the standard specimen and the length of image, to measure the ratio between the actual product and the camera image. A defect is found by the assembled visual inspection system. The inspection algorithm which estimates the quality of welded product is developed and also, the software program which processes the automatic test function of the inspection system. We make the foundation of the inspection automatic system and we will help to apply other welding machine.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.475-476
• /
• 2018

In this paper, we propose a method to measure the number of biofouling attached to underwater structures. This method measures the number of biofouling based on digital images captured in underwater. The number of biofouling was measured after correcting the image quality of underwater images for accurate population counting. In order to measure the number of biofouling, Maxima value in the image was found.

• Journal of Korea Multimedia Society
• /
• v.8 no.3
• /
• pp.313-321
• /
• 2005

Digital halftoning is a process to produce a binary image so that the original image and its binary counterpart appear similar when observed from a distance. Among digital halftoning methods, error diffusion is a procedure for generating high quality bilevel images from continuous-tone images but blurs the edge information in the bilevel images. To solve this problem, we propose the improved error diffusion using local spatial information of the original images. Based on the fact that the human vision perceives not a pixel but local mean of input image, we compute edge enhancement information(EEI) by appling the ratio of a pixel and its adjacent pixels to local mean. The weights applied to local means is computed using the ratio of local activity measure(LAM) to the difference between input pixels of 3$\times$3 blocks and theirs mean. LAM is the measure of luminance changes in local regions and is obtained by adding the square of the difference between input pixels of 3$\times$3 blocks and theirs mean. We add the value to a input pixel of quantizer to enhance edge. The performance of the proposed method is compared with conventional methods by measuring the edge correlation. The halftone images by using the proposed method show better quality due to the enhanced edge. And the detailed edge is preserved in the halftone images by using the proposed method. Also the proposed method improves the quality of halftone images because unpleasant patterns for human visual system are reduced.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.10
• /
• pp.28-39
• /
• 1996

The methodology is suggested to measure the quality of service in telecommunications. Through questionnaire, the subjective evaluation of users is surveyed, and quantified by MOS method. The MOS mehtod has some problems in interpretation which are mentioned in this paper. The cumulative percent curve is proposed to evaluate the quality of service. As an example, the image quality of G3 facsimile is measured.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.6_2
• /
• pp.665-672
• /
• 2012

Amid rapidly increasing imagery inputs and their volume in a remote sensing imagery database, Content-Based Image Retrieval (CBIR) is an effective tool to search for an image feature or image content of interest a user wants to retrieve. It seeks to capture salient features from a 'query' image, and then to locate other instances of image region having similar features elsewhere in the image database. For a CBIR approach that uses texture as a primary feature primitive, designing a texture descriptor to better represent image contents is a key to improve CBIR results. For this purpose, an extended feature vector combining the Gabor filter and co-occurrence histogram method is suggested and evaluated for quantitywise and qualitywise retrieval performance criterion. For the better CBIR performance, assessing similarity between high dimensional feature vectors is also a challenging issue. Therefore a number of distance metrics (i.e. L1 and L2 norm) is tried to measure closeness between two feature vectors, and its impact on retrieval result is analyzed. In this paper, experimental results are presented with several CBIR samples. The current results show that 1) the overall retrieval quantity and quality is improved by combining two types of feature vectors, 2) some feature is better retrieved by a specific feature vector, and 3) retrieval result quality (i.e. ranking of retrieved image tiles) is sensitive to an adopted similarity metric when the extended feature vector is employed.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.453-455
• /
• 2004

The quality of agricultural products is represented a degree of freshness and a special quality related to a commercial value. To grade cucumber, the charge-coupled device(CCD) camera is only used to measure external qualities like color. size and degree of bended cucumber The processed area of the image replaces the weigh of cucumber. That means there is no longer used the weighing beams. The system consists of Image processing system and distributing system. This paper explains the structure and movement of the automatic grade system and applies the algorithm for deformed cucumber and characteristics of cucumber through image processing to the grade system.

• Journal of Biomedical Engineering Research
• /
• v.23 no.4
• /
• pp.263-268
• /
• 2002

The image quality of imageguide depends on the structure, material, length of microfibers and the phenomena such as cross-talk and leaky ray between adjacent fibers. These Parameters should be considered as important factors in the image transmission qualify of fibers. However it is considered to be very difficult to assess all the parameters in a consistent way Therefore. two image characteristics, image resolution and image brightness are measured and analyzed to determine the image quality of imageguide. But the exact methods to measure two image characteristics of imageguide are not reported. In this study, the image brightness of imageguide for ultrathin endoscope is determined by measuring of the numerical aperture. the packing fraction and the attenuated power ratio of imageguide. Especially it is possible to obtain more exact results from measuring the numerical aperture of whole image guide than those from theoretical calculation of the single microfiber in an image guide. The image brightness of the image guide which has $3.1\mu m$ microfibers is about 37% less than that with $4.1\mu m$ microfibers.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.05a
• /
• pp.1677-1683
• /
• 2006

Color image segmentation is useful for fast retrieval in large image database. For that purpose, new image segmentation technique based on the probability of pixel distribution in the image is proposed. Color image is first divided into R, G, and B channel images. Then, pixel distribution from each of channel image is extracted to select to which it is similar among the well known probabilistic distribution function-Weibull, Exponential, Beta, Gamma, Normal, and Uniform. We use sum of least square error to measure of the quality how well an image is fitted to distribution. That P.d.f has minimum score in relation to sum of square error is chosen. Next, each image is quantized into 4 gray levels by applying thresholds to the c.d.f of the selected distribution of each channel. Finally, three quantized images are combined into one color image to obtain final segmentation result. To show the validity of the proposed method, experiments on some images are performed.

• Journal of the Semiconductor & Display Technology
• /
• v.18 no.3
• /
• pp.66-71
• /
• 2019

In shape from focus (SFF) methods, the quality of image focus volume plays a vital role in the quality of 3D shape reconstruction. Traditionally, a linear 2D filter is applied to each slice of the image focus volume to rectify the noisy focus measurements. However, this approach is problematic because it also modifies the accurate focus measurements that should ideally remain intact. Therefore, in this paper, we propose to enhance the focus volume adaptively by applying 3-dimensional weighted least squares (3D-WLS) based regularization. We estimate regularization weights from the guidance volume extracted from the image sequences. To solve 3D-WLS optimization problem efficiently, we apply a technique to solve a series of 1D linear sub-problems. Experiments conducted on synthetic and real image sequences demonstrate that the proposed method effectively enhances the image focus volume, ultimately improving the quality of reconstructed shape.

• Journal of Korea Multimedia Society
• /
• v.11 no.4
• /
• pp.462-470
• /
• 2008

This study applies fuzzy functions to improve image quality under the assumption that uncertainty of image information due to low contrast is based on vagueness and ambiguity of the brightness pixel values. To solve the problem of low contrast images whose brightness distribution is inclined, we use the k-means algorithm as a parameter of the fuzzy function, through which automatic critical points can be found to differentiate objects from background and contrast between bright and dark points can be improved. The fuzzy function is presented at the three main stages presented to improve image quality: fuzzification, contrast enhancement and defuzzification. To measure improved image quality, we present the fuzzy index and entropy index and in comparison with those of histogram equalization technique, it shows outstanding performance.