We propose a technique for generating the MPEG-7 descriptor in compressed image/video data. Image processing in the transform domain is a much interesting area recently because compressed image and video data are becoming widely available with the data format like MPEG or JPEG.. In general, processing in the transform domain requires smaller data quantities, and lower computation complexity than that in the spatial domain. In this paper, we propose a generation algorithm of the MPEG-7 metadata in the compressed domain. We have developed an algorithm to get the homogeneous texture descriptor in the compressed domain.
Good watermark needs to be perceptually invisible, undetectable without key and robust to spatial/temporal data modification. In this paper, we utilize the characteristics of the human visual system (HVS) where the response of visual cortex decomposes the image spectra into perceptual channels that are bands in spatial frequency. In the HVS, the spatial frequency domain is divided into octave-bands division in the radial axis. Based on the octave-bands division, a watermark is inserted into the channels which have same number of bits of the watermark. In doing so, more bits of the watermark are embedded into significant portions, which locate in the low-middle frequency region in the frequency domain. The above watermark insertion scheme gives a robustness because the watermark of significant portion can resist against strong attack of image. Experimental results show that the proposed method based on HVS method gives more robustness to the attacks compared with the conventional DCT, wavelet and DFT watermarking methods.
We propose a content based watermarking technique using the MPEG-7 texture descriptor. In the proposed technique, content description technique of MPEG-7 is adopted to watermarking technique. Using multimedia features described by MPEG-7 standard, we propose a watermarking technique where MPEG-7 texture descriptors are regarded as perceptually significant portions. In this paper, the MPEG-7 texture descriptor is utilized to find perceptually significant portion of data for the watermarking. The positions where the watermark is inserting are chosen according to the texture descriptor in DFT domain. In the detection, the texture descriptor is also utilized so that some frequency regions are weighted in the detection procedure. Experimental results show that the proposed method outperforms the conventional transformed watermarking techniques.
We propose a content based watermarking technique in multimedia management system. In the proposed technique, a content description technique of MPEG-7 for the multimedia database is adopted into a watermarking technique. With multimedia features described by MPEG-7 standard, we propose a novel watermarking technique where MPEG-7 descriptors are regarded as perceptually significant portions. The watermark is embedded in cooperating with multimedia features such as MPEG-7 descriptor. To verify the feasibility and performance of proposed watermarking technique, experiments with the MPEG-7 database are performed
In this paper, a multimedia database system is proposed using MPEG-7 meta data. Multimedia content based retrieval system is implemented with the MPEG-7 meta data by use of a data hiding technique. MPEG-7 descriptor and descriptor scheme are hidden into the original data using data hiding and watermarking technique. The hidden data is used as a query for the multimedia indexing/retrieval system. In this paper, color and texture descriptors and their descriptor scheme are used for the MPEG-7 multimedia database. To verify the usefulness of the proposed descriptor for contents featuring of texture, computer simulations and experiments with MPEG-7 image database were performed.
We propose a multimedia indexing/retrieval system which can provide content-based retrieval based on MPEG-7 description. In this paper, the database is built so that MPEG-7 descriptor and descriptor cheme are hid into video sequence using water marking technique. For a query by image example, similar images are extracted from the database by referring the hidden MPEG-7 metadata. To verify the effectiveness and efficiency of the proposed database, experiments with MPEG-7 texture descriptor were performed. Experimental results showed the proposed database gave fast and effective contents based retrieval.
We present a texture descriptor for multimedia contents description in MPEG-7. The current MPEG-7 candidate for the texture descriptor has been designed to be suitable for the human visual system (HVS). In this paper, the texture is described using perceptual channels that are bands in spatial frequency. Further, the MPEG-7 texture description method has employed Radon Transformation that is suitable for HVS behavior. By taking average energy and energy deviation of the HVS channels, the texture descriptor is generated. To verify the performance of the texture descriptor, experiments with the MPEG-7 database are performed.
A pixel profile in the conventional burst sequence is so poor that excited area by burst sequence is a small portion of a pixel. This causes poor signal to noise ratio in burst image. In this paper, a frequency sweeping of RF pulse for burst imaging sequence is proposed to improve pixel profile. A burst pulse train is shaped by linear or nonlinear frequency sweeping function so that all the spins within a pixel are excited, thereby improving the signal to noise ratio. It also shows that the pixel profiles are dependent on how the frequency sweep is made. Computer simulations with Bloch equation and experimental results obtained using a 1.0 T NMR imaging system are presented.