The Experts below are selected from a list of 146010 Experts worldwide ranked by ideXlab platform
Wenhsiang Tsai - One of the best experts on this subject based on the ideXlab platform.
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a new secure Image transmission technique via secret fragment visible mosaic Images by nearly reversible color transformations
IEEE Transactions on Circuits and Systems for Video Technology, 2014Co-Authors: Yalin Lee, Wenhsiang TsaiAbstract:A new secure Image transmission technique is proposed, which transforms automatically a given large-volume secret Image into a so-called secret-fragment-visible mosaic Image of the same size. The mosaic Image, which looks similar to an arbitrarily selected Target Image and may be used as a camouflage of the secret Image, is yielded by dividing the secret Image into fragments and transforming their color characteristics to be those of the corresponding blocks of the Target Image. Skillful techniques are designed to conduct the color transformation process so that the secret Image may be recovered nearly losslessly. A scheme of handling the overflows/underflows in the converted pixels' color values by recording the color differences in the untransformed color space is also proposed. The information required for recovering the secret Image is embedded into the created mosaic Image by a lossless data hiding scheme using a key. Good experimental results show the feasibility of the proposed method.
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secret fragment visible mosaic Image a new computer art and its application to information hiding
IEEE Transactions on Information Forensics and Security, 2011Co-Authors: Ijen Lai, Wenhsiang TsaiAbstract:A new type of computer art Image called secret-fragment-visible mosaic Image is proposed, which is created automatically by composing small fragments of a given Image to become a Target Image in a mosaic form, achieving an effect of embedding the given Image visibly but secretly in the resulting mosaic Image. This effect of information hiding is useful for covert communication or secure keeping of secret Images. To create a mosaic Image of this type from a given secret color Image, the 3-D color space is transformed into a new 1-D colorscale, based on which a new Image similarity measure is proposed for selecting from a database a Target Image that is the most similar to the given secret Image. A fast greedy search algorithm is proposed to find a similar tile Image in the secret Image to fit into each block in the Target Image. The information of the tile Image fitting sequence is embedded into randomly-selected pixels in the created mosaic Image by a lossless LSB replacement scheme using a secret key; without the key, the secret Image cannot be recovered. The proposed method, originally designed for dealing with color Images, is also extended to create grayscale mosaic Images which are useful for hiding text-type grayscale document Images. An additional measure to enhance the embedded data security is also proposed. Good experimental results show the feasibility of the proposed method.
Christian Brosseau - One of the best experts on this subject based on the ideXlab platform.
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optimized fusion method based on adaptation of the rms time frequency criterion for simultaneous compression and encryption of multiple Images
Proceedings of SPIE, 2013Co-Authors: M Aldossari, Ayman Alfalou, Christian BrosseauAbstract:An extension of the recently proposed method of simultaneous compression and encryption of multiple Images [Opt. Lett. 35, 1914-1916 (2010)] is developed. This analysis allows us to find a compromise between compression rate and quality of the reconstructed Images for Target detection applications. This spectral compression method can significantly reduce memory size and can be easily implemented with a VanderLugt correlator (VLC). For that purpose, we determine the size of the useful spectra for each Target Image by exploiting the root-mean-square time-frequency criterion. This parameter is used to determine the allowed area of each Target Image within the compressed spectrum. Moreover, this parameter is adapted in order to minimize overlapping between the different spectra. For that purpose we add a shift function adapted to each spectra. Finally, the spectra are merged together by making use of a segmentation criterion. The latter compares the local energy relative to each pixel for each spectrum. Furthermore, it optimizes assignment of the considered pixel by taking into account the adjacent areas to the considered pixel. This permits to avoid the presence of isolated areas and small sized areas (less than 10 pixels). In this paper, we analyse and optimize the shift function needed to separate the different spectra. We use mean square error (MSE) for comparing compression rates. A series of tests with several video sequences show the benefit of this shift function on the quality of reconstructed Images and compression rate.
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exploiting root mean square time frequency structure for multiple Image optical compression and encryption
Optics Letters, 2010Co-Authors: Ayman Alfalou, Christian BrosseauAbstract:We report on a new algorithm to compress and encrypt simultaneously multiple Images (Target Images). This method, which is based upon a specific spectral multiplexing (fusion without overlapping) of the multiple Images, aims to achieve a single encrypted Image, at the output plane of our system, that contains all information needed to reconstruct the Target Images. For that purpose, we divide the Fourier plane of the Image to transmit into two types of area, i.e., specific and common areas to each Target Image. A segmentation criterion taking into account the rootmean- square duration of each Target Image spectrum is proposed. This approach, which consists of merging the input Target Images together (in the Fourier plane) allows us to reduce the information to be stored and/or transmitted (compression) and induce noise on the output Image (encryption). To achieve a good encryption level, a first key Image (containing biometric information and providing the intellectual property of the Target Images) is used. A second encryption key is inserted in the Fourier plane to ensure a relevant phase distribution of the different merged spectra. We also discuss how the encoding information can be optimized by minimizing the number of bits required to encode each pixel. © 2010 Optical Society of America
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exploiting root mean square time frequency structure for multiple Image optical compression and encryption
Optics Letters, 2010Co-Authors: Ayman Alfalou, Christian BrosseauAbstract:We report on an algorithm to compress and encrypt simultaneously multiple Images (Target Images). This method, which is based upon a specific spectral multiplexing (fusion without overlapping) of the multiple Images, aims to achieve a single encrypted Image, at the output plane of our system, that contains all information needed to reconstruct the Target Images. For that purpose, we divide the Fourier plane of the Image to transmit into two types of area, i.e., specific and common areas to each Target Image. A segmentation criterion taking into account the rms duration of each Target Image spectrum is proposed. This approach, which consists of merging the input Target Images together (in the Fourier plane) allows us to reduce the information to be stored and/or transmitted (compression) and induce noise on the output Image (encryption). To achieve a good encryption level, a first key Image (containing biometric information and providing the intellectual property of the Target Images) is used. A second encryption key is inserted in the Fourier plane to ensure a relevant phase distribution of the different merged spectra. We also discuss how the encoding information can be optimized by minimizing the number of bits required to encode each pixel.
Ayman Alfalou - One of the best experts on this subject based on the ideXlab platform.
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optimized fusion method based on adaptation of the rms time frequency criterion for simultaneous compression and encryption of multiple Images
Proceedings of SPIE, 2013Co-Authors: M Aldossari, Ayman Alfalou, Christian BrosseauAbstract:An extension of the recently proposed method of simultaneous compression and encryption of multiple Images [Opt. Lett. 35, 1914-1916 (2010)] is developed. This analysis allows us to find a compromise between compression rate and quality of the reconstructed Images for Target detection applications. This spectral compression method can significantly reduce memory size and can be easily implemented with a VanderLugt correlator (VLC). For that purpose, we determine the size of the useful spectra for each Target Image by exploiting the root-mean-square time-frequency criterion. This parameter is used to determine the allowed area of each Target Image within the compressed spectrum. Moreover, this parameter is adapted in order to minimize overlapping between the different spectra. For that purpose we add a shift function adapted to each spectra. Finally, the spectra are merged together by making use of a segmentation criterion. The latter compares the local energy relative to each pixel for each spectrum. Furthermore, it optimizes assignment of the considered pixel by taking into account the adjacent areas to the considered pixel. This permits to avoid the presence of isolated areas and small sized areas (less than 10 pixels). In this paper, we analyse and optimize the shift function needed to separate the different spectra. We use mean square error (MSE) for comparing compression rates. A series of tests with several video sequences show the benefit of this shift function on the quality of reconstructed Images and compression rate.
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exploiting root mean square time frequency structure for multiple Image optical compression and encryption
Optics Letters, 2010Co-Authors: Ayman Alfalou, Christian BrosseauAbstract:We report on a new algorithm to compress and encrypt simultaneously multiple Images (Target Images). This method, which is based upon a specific spectral multiplexing (fusion without overlapping) of the multiple Images, aims to achieve a single encrypted Image, at the output plane of our system, that contains all information needed to reconstruct the Target Images. For that purpose, we divide the Fourier plane of the Image to transmit into two types of area, i.e., specific and common areas to each Target Image. A segmentation criterion taking into account the rootmean- square duration of each Target Image spectrum is proposed. This approach, which consists of merging the input Target Images together (in the Fourier plane) allows us to reduce the information to be stored and/or transmitted (compression) and induce noise on the output Image (encryption). To achieve a good encryption level, a first key Image (containing biometric information and providing the intellectual property of the Target Images) is used. A second encryption key is inserted in the Fourier plane to ensure a relevant phase distribution of the different merged spectra. We also discuss how the encoding information can be optimized by minimizing the number of bits required to encode each pixel. © 2010 Optical Society of America
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exploiting root mean square time frequency structure for multiple Image optical compression and encryption
Optics Letters, 2010Co-Authors: Ayman Alfalou, Christian BrosseauAbstract:We report on an algorithm to compress and encrypt simultaneously multiple Images (Target Images). This method, which is based upon a specific spectral multiplexing (fusion without overlapping) of the multiple Images, aims to achieve a single encrypted Image, at the output plane of our system, that contains all information needed to reconstruct the Target Images. For that purpose, we divide the Fourier plane of the Image to transmit into two types of area, i.e., specific and common areas to each Target Image. A segmentation criterion taking into account the rms duration of each Target Image spectrum is proposed. This approach, which consists of merging the input Target Images together (in the Fourier plane) allows us to reduce the information to be stored and/or transmitted (compression) and induce noise on the output Image (encryption). To achieve a good encryption level, a first key Image (containing biometric information and providing the intellectual property of the Target Images) is used. A second encryption key is inserted in the Fourier plane to ensure a relevant phase distribution of the different merged spectra. We also discuss how the encoding information can be optimized by minimizing the number of bits required to encode each pixel.
Yalin Lee - One of the best experts on this subject based on the ideXlab platform.
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a new secure Image transmission technique via secret fragment visible mosaic Images by nearly reversible color transformations
IEEE Transactions on Circuits and Systems for Video Technology, 2014Co-Authors: Yalin Lee, Wenhsiang TsaiAbstract:A new secure Image transmission technique is proposed, which transforms automatically a given large-volume secret Image into a so-called secret-fragment-visible mosaic Image of the same size. The mosaic Image, which looks similar to an arbitrarily selected Target Image and may be used as a camouflage of the secret Image, is yielded by dividing the secret Image into fragments and transforming their color characteristics to be those of the corresponding blocks of the Target Image. Skillful techniques are designed to conduct the color transformation process so that the secret Image may be recovered nearly losslessly. A scheme of handling the overflows/underflows in the converted pixels' color values by recording the color differences in the untransformed color space is also proposed. The information required for recovering the secret Image is embedded into the created mosaic Image by a lossless data hiding scheme using a key. Good experimental results show the feasibility of the proposed method.
Jen King Jao - One of the best experts on this subject based on the ideXlab platform.
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theory of synthetic aperture radar imaging of a moving Target
IEEE Transactions on Geoscience and Remote Sensing, 2001Co-Authors: Jen King JaoAbstract:Two novel Image processing techniques have been developed to refocus a moving Target Image from its smeared response in the synthetic aperture radar (SAR) Image which is focused on the stationary ground. Both approaches may be implemented with efficient fast Fourier transform (FFT) routines to process the Fourier spatial spectrum of the Image data. The first approach utilizes a matched Target filter that is derived from the signal history along the range-Doppler migration path mapped onto the SAR Image from the moving Target trajectory in real space. The coherent spatial filter is specified by the apparent Target range in the Image and the magnitude of the relative Target-to-radar velocity. The second approach eliminates the range-dependence by reconstructing the moving Target Image from a spectral function that is obtained from the SAR Image data spectrum via a spatial frequency coordinate transformation.
