• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.35-40
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• 2019

In this paper, we propose a technique to reconstruct the iris image from the iris code by analyzing the process of generating the iris code and calculating it inversely. Iris recognition is an authentication method for authenticating an individual's identity by using iris information of an eye having unique information of an individual. The iris recognition extracts the features of the iris from the iris image, creates the iris code, and determines whether to authenticate using the corresponding code. The iris recognition method using the iris code is a method proposed by Daugman for the first time and is widely used as a representative method of iris recognition technology currently used commercially. In this paper, we restore the iris image with only the iris code, and test whether the reconstructed image and the original image can be recognized, and analyze restoration vulnerability of Daugman's iris code.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.150-159
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• 2005

With the increase of interest in ubiquitous computing, image code is attracting attention in various areas. Image code is important in ubiquitous computing in that it can complement or replace RFID (radio frequency identification) in quite a few areas as well as it is more economical. However, because of the difficulty in reading precise colors due to the severe distortion of colors, its application is quite restricted by far. In this paper, we present an efficient method of image code recognition including automatically locating the image code using the hue and saturation values. In our experiments, we use an image code whose design seems most practical among currently commercialized ones. This image code uses six safe colors, i.e., R, G, B, C, M, and Y. We tested for 72 true-color field images with the size of $2464{\times}1632$ pixels. With the color calibration based on the histogram, the localization accuracy was about 96%, and the accuracy of color classification for localized codes was about 91.28%. It took approximately 5 seconds to locate and recognize the image code on a PC with 2 GHz P4 CPU.

• Current Optics and Photonics
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• v.4 no.4
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• pp.302-309
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• 2020

An image encryption scheme based on the quick response (QR) code as a data container has aroused wide interest due to the lossless recovery of the decrypted image. In this paper, we apply this method to multi-image encryption. However, since the decrypted image is affected by crosstalk noise, the number of multi-image encryptions is severely limited. To solve this problem, we analyzed the performance of QR code as a data container, and processed the decrypted QR code using the proposed method, so that the number of multi-image encryptions is effectively increased. Finally, we implemented a large image (256 × 256) encryption and decryption.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.69-72
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• 2005

As life style becomes to be complicated, lots of support technologies were developed. The bar code technology is one of them. It was renovating approach to goods industry. However, data storage ability in one dimension bar code came in limit because of industry growth. Two-dimension bar code was proposed to overcome one-dimension bar code. PDF417 bar code most commonly used in standard two-dimension bar codes is well defined at data decoding and error correction area. More works could be done in bar code image acquisition process. Applying various image enhancement algorithms, the recognition rate of PDF417 bar code is improved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.122-130
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• 2009

The paper presents an algorithm which uses code vectors to represent comer geometry information for searching the similar images from a database. The comers have been extracted by finding the intersections of the detected lines found using Hough transform. Taking the comer as the center coordinate, the angles of the intersecting lines are determined and are represented using code vectors. A code book has been used to code each comer geometry information and indexes to the code book are generated. For similarity measurement, the histogram of the code book indexes is used. This result in a significant small size feature matrix compared to the algorithms using color features. Experimental results show that use of code vectors is computationally efficient in similarity measurement and the comers being noise invariant produce good results in noisy environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.471-485
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• 2023

As data sharing increases explosively, such information encoded in QR code is completely public as private messages are not securely protected. This paper proposes a new 'PROMISE' framework for hiding information based on the QR code projection matrix by using image segmentation without modifying the essential QR code characteristics. Projection matrix mapping, matrix scrambling, fusion image segmentation and steganography with SEL(secret embedding logic) are part of the PROMISE framework. The QR code could be mapped to determine the segmentation site of the fusion image as a binary information matrix. To further protect the site information, matrix scrambling could be adopted after the mapping phase. Image segmentation is then performed on the fusion image and the SEL module is applied to embed the secret message into the fusion image. Matrix transformation and SEL parameters should be uploaded to the server as the secret key for authorized users to decode the private message. And it was possible to further obtain the private message hidden by the framework we proposed. Experimental findings show that when compared to some traditional information hiding methods, better anti-detection performance, greater secret key space and lower complexity could be obtained in our work.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.3
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• pp.103-111
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• 2009

Software update has been regarded as one of fundamental functions in wireless sensor networks. It can disseminate a delta-image between a current software image operating on a sensor node and its new image in order to reduce an update image(transmission data) size, resultantly saving energy. In addition, code-banking capability of micro-controllers can decrease the update image size. In order to maximize the efficiency of the software update, the proposed scheme exploits both the delta-image and the code-banking at the same time. Besides, it additionally delivers a recovery delta-image to properly handle abnormal conditions, such as message corruptions and unexpected power-off during the update.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.375-378
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• 2000

In this paper, we propose a novo] content-based image retrieval system using both Hidden Markov Model(HMM) and an improved chain code. The Gaussian Mixture Model(GMM) is applied to statistically model a color information of the image, and Deterministic Annealing EM(DAEM) algorithm is employed to estimate the parameters of GMM. This result is used to segment the given image. We use an improved chain code, which is invariant to rotation, translation and scale, to extract the feature vectors of the shape for each image in the database. These are stored together in the database with each HMM whose parameters (A, B, $\pi$) are estimated by Baum-Welch algorithm. With respect to feature vector obtained in the same way from the query image, a occurring probability of each image is computed by using the forward algorithm of HMM. We use these probabilities for the image retrieval and present the highest similarity images based on these probabilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.663-673
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• 2011

Applications of two dimensional image codes like QR and color code on mobile phone are spreading widely and in lieu of that, better decoding technology and platform designs are required. Futhermore "Bokode" technology which recognizes the defocus-blur image information from imperceptible visual tiny code on ordinary digital camera has been announced newly. There is an urgent need for competitive strategies to activate 2D image code industry and R&D under smart environment. This paper focused on suggesting valuable idea and practical task through investigation and analysis required for supporting of thus strategy construction. Description consist of introduction, technological tendency for R&D, patent and market, implementation task, conclusion and suggestion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2005-2021
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• 2014

This paper proposes a novel image authentication scheme, aiming at tampering detection for block truncation coding (BTC) compressed image. The authentication code is generated by using the random number generator with a seed, and the size of the authentication code is based on the user's requirement, with each BTC-compressed image block being used to carry the authentication code using the data hiding method. In the proposed scheme, to obtain a high-quality embedded image, a reference table is used when the authentication code is embedded. The experimental results demonstrate that the proposed scheme achieves high-quality embedded images and guarantees the capability of tamper detection.