Dong-Gyu Yeo

High capacity reversible watermarking using differential histogram shifting and predicted error compensation

Reversible watermarking inserts watermarks into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications where high capacity and high visual quality are major requirements for reversible watermarking. This work presents a new reversible watermarking algorithm that embeds message bits by modifying the differential histogram of adjacent pixels. To satisfy both high embedding capacity and visual quality, the proposed technique exploits the fact that the adjacent pixels are highly correlated. Also, we prevent overflow and underflow problems by designing a predicted error compensation scheme. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, higher capacity, and higher visual quality than any previous method, while maintaining low induced distortion.

Automatic Music Mood Detection through Musical Structure Analysis

Since music has a close relation with people emotion, many researchers have studied on detecting music mood. Usually, they manually selected the representative segment of music and classified its mood. Although such manual approaches correctly detect the mood, their manual intervention makes their application for new music difficult. Moreover, the mood variation in music makes their application more difficult. To cope with these problems, we present an automatic method to classify the music mood. After the music is segmented into groups having similar characteristics by structural information, the support vector regressors are constructed with musical features from pitch, beat, and spectrum of each segment. The mood of unknown music is predicted by the regressors. Experimental results show that performance of the proposed approach is comparable to the performances of manual approaches.

Block-based Image Authentication Algorithm Using Reversible Watermarking

For the application which need high-confidential images, reversible watermarking method can be regarded as an effective mean to ensure the integrity of received images. Many researches about contents authenticating cannot recover the original image. Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications, where high capacity and high visual quality are major requirements. This paper presents a new block-based image authentication algorithm using differential histogram-based reversible watermarking which is able to detect malicious tampering. To judge whether malformed or not, the presented scheme use the DCT-based authentication feature. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides over 97% authenticating rate, complete reversibility, and higher visual quality, while maintaining the induced-distortion low.

Block-based Image Authentication Algorithm using Differential Histogram-based Reversible Watermarking

In most applications requiring high-confidential images, reversible watermarking is an effective way to ensure the integrity of images. Many watermarking researches which have been adapted to authenticate contents cannot recover the original image after authentication. However, reversible watermarking inserts the watermark signal into digital contents in such a way that the original contents can be restored without any quality loss while preserving visual quality. To detect malicious tampering, this paper presents a new block-based image authentication algorithm using differential histogram-based reversible watermarking. To generate an authentication code, the DCT-based authentication feature from each image block is extracted and combined with user-specific code. Then, the authentication code is embedded into image itself with reversible watermarking. The image can be authenticated by comparing the extracted code and the newly generated code and restored into the original image. Through experiments using multiple images, we prove that the presented algorithm has achieved over 97% authentication rate with high visual quality and complete reversibility.

Detection of Music Mood for Context-aware Music Recommendation

ABSTRACT To provide context-aware music recommendation service, first of all, we need to catch music mood that a user prefers depending on his situation or context. Among various music characteristics, music mood has a close relation with people’s emotion. Based on this relationship, some researchers have studied on music mood detection, where they manually select a representative segment of music and classify its mood. Although such approaches show good performance on music mood classification, its difficult to apply them to new music due to the manual intervention. Moreover, it is more difficult to detect music mood because the mood usually varies with time.To cope with these problems, this paper presents an automatic method to classify the music mood. First, a whole music is segmented into several groups that have similar characteristics by structural information. Then, the mood of each segments is detected, where each individuals preference on mood is modelled by regression based on Thayers two-dimensional mood model. Experimental results show that the proposed method achieves 80% or higher accuracy.Keywords:Context-aware Music Recommendation; Musical Genre Classification; Musical Structure Analysis; Salient Segment Detection; Content-based Musical Feature Extraction

Integrity Authentication Algorithm of JPEG Compressed Images through Reversible Watermarking

Multimedia contents can be copied and manipulated without quality degradation. Therefore, they are vulnerable to digital forgery and illegal distribution. In these days, with increasing the importance of multimedia security, various multimedia security techniques are studied. In this paper, we propose a content authentication algorithm based on reversible watermarking which supports JPEG compression commonly used for multimedia contents. After splitting image blocks, a specific authentication code for each block is extracted and embedded into the quantized coefficients on JPEG compression which are preserved against lossy processing. At a decoding process, the watermarked JPEG image is authenticated by extracting the embedded code and restored to have the original image quality. To evaluate the performance of the proposed algorithm, we analyzed image quality and compression ratio on various test images. The average PSNR value and compression ratio of the watermarked JPEG image were 33.13dB and 90.65%, respectively, whose difference with the standard JPEG compression were 2.44dB and 1.63%.

Interval-based Audio Integrity Authentication Algorithm using Reversible Watermarking

Many audio watermarking researches which have been adapted to authenticate contents can not recover the original media after watermark removal. Therefore, reversible watermarking can be regarded as an effective method to ensure the integrity of audio data in the applications requiring high-confidential audio contents. Reversible watermarking inserts watermark into digital media in such a way that perceptual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. This paper presents a new interval-based audio integrity authentication algorithm which can detect malicious tampering. To provide complete reversibility, we used differential histogram-based reversible watermarking. To authenticate audio in parts, not the entire audio at once, the proposed algorithm processes audio by dividing into intervals and the confirmation of the authentication is carried out in each interval. Through experiments using multiple kinds of test data, we prove that the presented algorithm provides over 99% authenticating rate, complete reversibility, and higher perceptual quality, while maintaining the induced-distortion low.

Performance Enhancement through Row-Column Cross Scanning in Differential Histogram-based Reversible Watermarking

Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. It has various applications, where high capacity and high visual quality are major requirements. This paper presents a new effective multi-round embedding scheme for the differential histogram-based reversible watermarking that satisfies high capacity requirements of the application. The proposed technique exploits the row-column cross scanning to fully utilize the locality of images when multi-round embedding phase to the message inserted image. Through experiments using multiple kinds of test images, we prove that the presented algorithm provides 100% reversibility, effectiveness of multi-round embedding, and higher visual quality, while maintaining the induced-distortion low.

Differential Histogram Modification-Based Reversible Watermarking with Predicted Error Compensation

Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved and the original media can be restored from the marked one without any loss of media quality. High capacity and high visual quality are a major requirement for reversible watermarking. In this paper, we present a novel reversible watermarking scheme that embeds message bits by modifying the differential histogram of adjacent pixels. Also, overflow and underflow problem is prevented with the proposed predicted error compensation scheme. Through experiments on various images, we prove that the presented scheme achieves 100% reversibility, high capacity, and high visual quality over other methods, while maintaining the induced-distortion low.