• Journal of Korea Multimedia Society
• /
• v.8 no.11
• /
• pp.1462-1471
• /
• 2005

Recently, the medical image has been digitized by the development of computer science and digitization of the medical devices. There are needs for database service of the medical image and long term storage because of the construction of PACS(picture archiving and communication system) following DICOM(digital imaging communications in medicine) standards, telemedicine, and et al. However, it also caused some kinds of problems, such as illegal reproduction of medical image, proprietary rights and data authentication. In this paper, we propose the new digital watermarking technique for medical image based on public key encryption algorithm for integrity verification. It prevents illegal forgery that can be caused after transmitting medical image data remotely. The watermark is the value of bit-plane in wavelet transform of the original image for certification method of integrity verification. We proposed the embedding regions are randomly chosen considering ROI, and a digital signature is made using hash function of MD5 which input is a secret key. The experimental results show that the watermark embedded by the proposed algorithm can survive successfully in image processing operations and that the watermark's invisibility is good.

• Journal of KIISE:Computing Practices and Letters
• /
• v.10 no.3
• /
• pp.243-250
• /
• 2004

We describe a practical implementation of DVR (Digital Video Recording) system. And we propose a new image compression algorithm, that input video signal is divided into two parts, a moving target and a non-moving background part to achieve efficient compression of image sequences. This algorithm reorganizes a target area and a back-ground area by use of Macro Block(MB) unit on encoding scheme. The proposed algorithm allows high quality image reconstruction at low bit rates.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.511-515
• /
• 2008

디지털 워터마크 기법은 음악, 영상, 동영상에 대한 저작권과 재산권의 보호 및 인증, 데이터 손실 여부 판단, 복사 방지 및 추적 등을 목적으로 한 사후 재산권의 보호 기술로 제안되었다. 본 연구에서는 워터마크의 기하학적인 왜곡에 대한 공격에 견고하게 하도록 영상의 전 처리 과정을 거친다. 그리고 선택된 기하학적인 불변점을 골라 여러 가지 영상처리에 강인하며 일정 기간 압축 저장되는 영상에서도 워터마킹이 유지되도록 워터쉐드(watershed) 분할 기법을 이용한 의료 영상 보안 알고리즘을 제안한다. 본 논문에서 제안한 워터마킹 알고리즘은 의료 영상에 대한 RST 공격, JPEG 압축 공격 그리고 필터링 공격보다 강인함을 확인하였다.

• The KIPS Transactions:PartB
• /
• v.17B no.5
• /
• pp.333-344
• /
• 2010

This paper addresses the way to compose paronamic images from images taken the same objects. With the spread of digital camera, the panoramic image has been studied to generate with its interest. In this paper, we propose a panoramic image generation method using scaling and rotation invariant features. First, feature points are extracted from input images and matched with a RANSAC algorithm. Then, after the perspective model is estimated, the input image is registered with this model. Since the SURF feature extraction algorithm is adapted, the proposed method is robust against geometric distortions such as scaling and rotation. Also, the improvement of computational cost is achieved. In the experiment, the SURF feature in the proposed method is compared with features from Harris corner detector or the SIFT algorithm. The proposed method is tested by generating panoramic images using $640{\times}480$ images. Results show that it takes 0.4 second in average for computation and is more efficient than other schemes.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.9
• /
• pp.2265-2271
• /
• 2014

In modern society digital equipments that are related with various hardware and software are popularized, and digital images are widely applied in the field of production and scientific research. In general, however, images are degraded by the noise in the process of transmission and storage. In this paper, to reduce the influence of mixed noises, the algorithm in which noises in the space area are classified into impulse noise and Gaussian noise and this is processed by applying weighted value, while that is processed by modified nonlinear filter is proposed. And the excellence of the proposed algorithm is judged by PSNR(peak signal to noise ratio).

• Korean journal of applied entomology
• /
• v.42 no.1
• /
• pp.57-63
• /
• 2003

Accurate forecasting of occurrence time and abundance of insect pests is essential for developing technology of integrated pest management system. Digital image processing algorithms were utilized to automatically recognize rice planthoppers which are major insect pests in the rice cultivation field and were subsequently used to estimate densities in the field for efficient forecasting of insect pests. To the images taken in the rice field, image decomposition, top-hat transformation, threshold, and minimum and maximum filter were implemented for patterning individually the brown planthopper specimens attached at the bottom area of rice stems. In average 95.8cio of images were correctly recognized for estimating densities by the developed system, and the recognition rate was higher than that obtained from direct observations by experienced observers. Furthermore, the size of the recognized specimens was measured and was used for estimating the age structure in the observed brown planthopper populations.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.11
• /
• pp.3576-3583
• /
• 2000

Digital watermarks have recently been proposed for the purposes of copyright ptotechtion and autheutication for multimedia contents. A watermarking technique consists of an algorithm that incorporates a watermarking structure into an image in the spatial or frequency domains. In this paper we proposed a new watermarking method for authentication and integrity of digital images and the proposed algorithm uses the MD5 hash funiction and a symmetric key encryption algorithm. To decide the position of embedding watermark and the bit pasitionin the original image, the secret key is used as an input of the MD5 hash function. The simulation results show that the proposed algorithm has the advantage of difficulty to find positions of inserted watermarks, and keep the similar watermarked image quabty with Wong's method.

• The KIPS Transactions:PartB
• /
• v.10B no.4
• /
• pp.419-428
• /
• 2003

Recently, digital watermarking has been proposed as a viable solution to the need of copyright protection and authentication of multimedia data. A robust wavelet-based watermark casting scheme and a watermark retrieval technique are suggested in this paper. We present a method which can add the watermark to the significant coefficients in the DWT domain, and does not require the original image in the detection process. In adaptive watermark casting method is developed to select perceptually significant coefficients for each subband using multiple threshold. In the proposed method, an adaptive multiple threshold scheme is used to reflect characteristics of each subband and complexity of image. The watermark is adaptively weighted in different subbands to achieve robustness as well as high perceptual quality. The watermark, Gaussian random sequence is added to the large coefficients but not in the lowest subband in the DWT domain. Experimental results show that the proposed algorithm produced visually very good watermarked image which has good invisibility to human eyes and very robust against various image processing and compression attacks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.05a
• /
• pp.207-209
• /
• 2021

In recent years, with the development of artificial intelligence and IoT technology, automation and unmanned technology are in progress in various fields, and the importance of image processing such as object tracking, medical images and object recognition, which are the basis of this, is increasing. In particular, in systems requiring detailed data processing, noise reduction is used as a pre-processing step, but the existing algorithm has a disadvantage that blurring occurs in the filtering process. Therefore, in this paper, we propose a filter algorithm using modified spatial weights to minimize information loss in the filtering process. The proposed algorithm uses mask matching to remove AWGN, and obtains the output of the filter by adding or subtracting the output of the modified spatial weight. The proposed algorithm has superior noise reduction characteristics compared to the existing method and reconstructs the image while minimizing the blurring phenomenon.

• Journal of Digital Convergence
• /
• v.12 no.11
• /
• pp.407-414
• /
• 2014

The aim of the present study was to carry out quantitative analysis of spatial resolution for the influence of the focus size and digital image post-processing on the Computed Radiography (CR). The modulation transfer functions of an edge measuring method (MTF) was used for the evaluation of the spatial resolution. The focus size of X-ray tube was used the small focus (0.6 mm) and the large focus (1.2 mm). We evaluated the 50% and 10% of MTF for the enhancement of edge and contrast by using multi-scale image contrast amplification (MUSICA) in digital image post-processing. As a results, the edge enhancement than the contrast enhancement were significantly higher the spatial resolution of MTF 50% in all focus. Also the spatial resolution of the obtained images in a large focus were improved by digital image processing. In conclusion, the results of this study should serve as a basic data for obtain the high resolution clinical images, such as skeletal and chest images on the CR.