Multi-modality medical image fusion has more and more important applications in medical image analysis and understanding. In this paper, we develop and apply a multi-resolution method based on wavelet pyramid to fuse ...Multi-modality medical image fusion has more and more important applications in medical image analysis and understanding. In this paper, we develop and apply a multi-resolution method based on wavelet pyramid to fuse medical images from different modalities such as PET-MRI and CT-MRI. In particular, we evaluate the different fusion results when applying different selection rules and obtain optimum combination of fusion parameters.展开更多
This paper presents a modified multi-resolution telescopic search algorithm (MRTlcSA) for the block-matching motion estimation. A novel inverse telescopic search is substituted for the conventional telescopic search, ...This paper presents a modified multi-resolution telescopic search algorithm (MRTlcSA) for the block-matching motion estimation. A novel inverse telescopic search is substituted for the conventional telescopic search, that reduces the on-chip memory size and memory bandwidth for VLSI implementation. In addition, strategies of motion track and adaptive search window are applied to reduce the computational complexity of motion estimation. Simulation results show that, compared with the MRTleSA, the proposed algorithm reduces the computational load to only 30% while preserving almost the same image quality. Comparisons on hardware cost and power consumption of the VLSI implementations using the two algorithms are also presented in the paper.展开更多
With the advances of display technology, three-dimensional(3-D) imaging systems are becoming increasingly popular. One way of stimulating 3-D perception is to use stereo pairs, a pair of images of the same scene acqui...With the advances of display technology, three-dimensional(3-D) imaging systems are becoming increasingly popular. One way of stimulating 3-D perception is to use stereo pairs, a pair of images of the same scene acquired from different perspectives. Since there is an inherent redundancy between the images of a stereo pairs, data compression algorithms should be employed to represent stereo pairs efficiently. The proposed techniques generally use block-based disparity compensation. In order to get the higher compression ratio, this paper employs the wavelet-based mixed-resolution coding technique to incorporate with SPT-based disparity-compensation to compress the stereo image data. The mixed-resolution coding is a perceptually justified technique that is achieved by presenting one eye with a low-resolution image and the other with a high-resolution image. Psychophysical experiments show that the stereo image pairs with one high-resolution image and one low-resolution image provide almost the same stereo depth to that of a stereo image with two high-resolution images. By combining the mixed-resolution coding and SPT-based disparity-compensation techniques, one reference (left) high-resolution image can be compressed by a hierarchical wavelet transform followed by vector quantization and Huffman encoder. After two level wavelet decompositions, for the low-resolution right image and low-resolution left image, subspace projection technique using the fixed block size disparity compensation estimation is used. At the decoder, the low-resolution right subimage is estimated using the disparity from the low-resolution left subimage. A full-size reconstruction is obtained by upsampling a factor of 4 and reconstructing with the synthesis low pass filter. Finally, experimental results are presented, which show that our scheme achieves a PSNR gain (about 0.92dB) as compared to the current block-based disparity compensation coding techniques.展开更多
A simple method based on CFD code and Matlab from CFD code due to the changes of such factors is introduced as an input to Matlab. The overall for aero-optic effects is presented. Density fluctuation as altitude, spee...A simple method based on CFD code and Matlab from CFD code due to the changes of such factors is introduced as an input to Matlab. The overall for aero-optic effects is presented. Density fluctuation as altitude, speed, equipment location, and wavelength calculations are in Matlab. The results show that the performance of electro-optical （EO） system can be improved when the altitude increasing, the speed is as slowly as possible, and the equipment location moves to the leading edge of the airborne platform as far as possible, for the wavelength there is an optimum one when the indexes of contrast and resolution of the system are both considered. All of these methods can minimize the optical aberrations. Several numerical simulations demonstrate the method.展开更多
The dynamical equation of a trapping cell is solved to find calibration methods for the trapping force, and two methods are compared by synthetic experiment data. Results indicate that： Boltzmann distribution method ...The dynamical equation of a trapping cell is solved to find calibration methods for the trapping force, and two methods are compared by synthetic experiment data. Results indicate that： Boltzmann distribution method （BDM） is available for the force calibration of non-spherical or anisotropic cells in arbitrary trap potential; the mean square displacement method （MSDM） is available only for a symmetric harmonic optical trap. The spatial resolution requirement of the calibration system is about a nanometer. The results agree with the reported experiments.展开更多
A new direction recognizing and subdividing method for moire (interference) fringes is presented. By setting two certain thresholds, counting errors caused by direct voltage excursion are avoided. Counting and directi...A new direction recognizing and subdividing method for moire (interference) fringes is presented. By setting two certain thresholds, counting errors caused by direct voltage excursion are avoided. Counting and direction recognizing are discussed in detail. Experimental results are given. The better adaptability and large subdivision number are the good quality of this method.展开更多
Based on the point spread function of holographic system, the lateral resolution of digital holographic imaging system without any pre-magnification is studied. The expression of resolution limitation of holo-graphic ...Based on the point spread function of holographic system, the lateral resolution of digital holographic imaging system without any pre-magnification is studied. The expression of resolution limitation of holo-graphic imaging system is thus presented. We investigate the possibilities to improve the lateral resolution. The simple experimental setup with an off-axis arrangement is built. By using a U.S. Air Force （USAF） test target as microscopic object, the recorded holograms are reconstructed digitally based on the principle of Fresnel diffraction. The lateral resolution of 2.76 μm without any pre-magnification is demonstrated experimentally, which matches the theoretical prediction well.展开更多
We present a method of time coding with ABAB synchronization timing control for real-time 3D superresolution range-gated imaging （3DSRGI）. To meet the high precision of time delay and pulse width in ABAB synchroniza...We present a method of time coding with ABAB synchronization timing control for real-time 3D superresolution range-gated imaging （3DSRGI）. To meet the high precision of time delay and pulse width in ABAB synchronization time sequencing, phase shift is implemented to achieve ns-scaled delay and width accuracy without restoring to high clock frequencies. Theoretical analysis and experiments prove that 1 ns delay and width precision is obtained by our timing control unit based on a single field-programmable gate array with 5 ns clock cycle. Finally, a prototype experiment of 3DSRGI is demonstrated at a 10 Hz video rate with 696 pixels × 520 pixels.展开更多
Compared with binary diffractive super-resolving elements, programmable super-resolution pupil filters permit the analysis of various filter designs and allow the filters to be changed rapidly to modify the response o...Compared with binary diffractive super-resolving elements, programmable super-resolution pupil filters permit the analysis of various filter designs and allow the filters to be changed rapidly to modify the response of an optical system. In this Letter, a deformable mirror is employed as a programmable super-resolution pupil phase filter. Continuous phase-only filters based on the Zernike polynomial series are designed by the genetic algorithm and fitted through closed-loop adaptive optics with a piezoelectric deformable mirror. Experimental superresolution results are in agreement with the theoretical predictions. This method has no polarization light requirement and is convenient for application.展开更多
A novel read-only memory （ROM） disk with an AgOx mask layer was proposed and studied in this letter, The AgOg, films sputtered on the premastered substrates, with pits depth of 50 nm and pits length of 380 nm, were ...A novel read-only memory （ROM） disk with an AgOx mask layer was proposed and studied in this letter, The AgOg, films sputtered on the premastered substrates, with pits depth of 50 nm and pits length of 380 nm, were studied by an atomic force microscopy. Tile transmittances of these AgOx films were also measured by a spectrophotometer. Disk measurement was carried out by a dynamic setup with a laser wavelength of 632.8 nm and a lens numerical aperture （NA） of 0.40. The readout resolution limit of this setup was λ/（4NA） （400 nm）. Results showed that the super-resolution readout happened only when the oxygen flow ratios were at suitable values for these disks. The best super-.resolution performance was achieved at the oxygen flow ratio of 0.5 with the smoothest fihn surface. The super-resolution readout mechanism of these ROM disks was analyzed as well.展开更多
The spectroscopic data recorded by dispersion spectrophotometer are usually degraded by the response function of the instrument. To improve the resolving power, double or triple cascade spectrophotometer and narrow sl...The spectroscopic data recorded by dispersion spectrophotometer are usually degraded by the response function of the instrument. To improve the resolving power, double or triple cascade spectrophotometer and narrow slits have been employed, but the total flux of the radiation decreases accordingly, resulting in a lower signal-to-noise ratio （SNR） and a longer measuring time. However, the spectral resolution can be improved by mathematically removing the effect of the instrument response function. Based on the ShalviWeinstein criterion, a Gauss-Newton based kurtosis blind deconvolution algorithm for spectroscopic data is proposed. Experiments with some real measured Raman spectroscopic data show that this algorithm has excellent deconvolution capability.展开更多
Many approaches for high-resolution image reconstruction have been proposed in some literatures. One of the most commonly ways is to reconstruct a high-resolution image from a number of rotated and translated images w...Many approaches for high-resolution image reconstruction have been proposed in some literatures. One of the most commonly ways is to reconstruct a high-resolution image from a number of rotated and translated images with low resolution. In this process, the exposure difference among original images will decrease the quality of the reconstructed image. In order to remove the influence of the exposure difference, a light energy matching method is proposed in this paper. The theoretical analysis is illustrated in details. Experimental results show that the theoretical analysis is correct and the proposed method is valid.展开更多
基金the National Natural Science Foundation of China (No. 19675005).
文摘Multi-modality medical image fusion has more and more important applications in medical image analysis and understanding. In this paper, we develop and apply a multi-resolution method based on wavelet pyramid to fuse medical images from different modalities such as PET-MRI and CT-MRI. In particular, we evaluate the different fusion results when applying different selection rules and obtain optimum combination of fusion parameters.
基金supported by China Postdoctoral Science Foundation(2015M582355)the Doctor Scientific Research Start Project from Hubei University of Science and Technology(BK1418)National Natural Science Foundation of China(61271256)
文摘This paper presents a modified multi-resolution telescopic search algorithm (MRTlcSA) for the block-matching motion estimation. A novel inverse telescopic search is substituted for the conventional telescopic search, that reduces the on-chip memory size and memory bandwidth for VLSI implementation. In addition, strategies of motion track and adaptive search window are applied to reduce the computational complexity of motion estimation. Simulation results show that, compared with the MRTleSA, the proposed algorithm reduces the computational load to only 30% while preserving almost the same image quality. Comparisons on hardware cost and power consumption of the VLSI implementations using the two algorithms are also presented in the paper.
基金This project was supported by the National Natural Science Foundation (No. 69972027).
文摘With the advances of display technology, three-dimensional(3-D) imaging systems are becoming increasingly popular. One way of stimulating 3-D perception is to use stereo pairs, a pair of images of the same scene acquired from different perspectives. Since there is an inherent redundancy between the images of a stereo pairs, data compression algorithms should be employed to represent stereo pairs efficiently. The proposed techniques generally use block-based disparity compensation. In order to get the higher compression ratio, this paper employs the wavelet-based mixed-resolution coding technique to incorporate with SPT-based disparity-compensation to compress the stereo image data. The mixed-resolution coding is a perceptually justified technique that is achieved by presenting one eye with a low-resolution image and the other with a high-resolution image. Psychophysical experiments show that the stereo image pairs with one high-resolution image and one low-resolution image provide almost the same stereo depth to that of a stereo image with two high-resolution images. By combining the mixed-resolution coding and SPT-based disparity-compensation techniques, one reference (left) high-resolution image can be compressed by a hierarchical wavelet transform followed by vector quantization and Huffman encoder. After two level wavelet decompositions, for the low-resolution right image and low-resolution left image, subspace projection technique using the fixed block size disparity compensation estimation is used. At the decoder, the low-resolution right subimage is estimated using the disparity from the low-resolution left subimage. A full-size reconstruction is obtained by upsampling a factor of 4 and reconstructing with the synthesis low pass filter. Finally, experimental results are presented, which show that our scheme achieves a PSNR gain (about 0.92dB) as compared to the current block-based disparity compensation coding techniques.
基金This work was supported by the National "863" Program of China.
文摘A simple method based on CFD code and Matlab from CFD code due to the changes of such factors is introduced as an input to Matlab. The overall for aero-optic effects is presented. Density fluctuation as altitude, speed, equipment location, and wavelength calculations are in Matlab. The results show that the performance of electro-optical （EO） system can be improved when the altitude increasing, the speed is as slowly as possible, and the equipment location moves to the leading edge of the airborne platform as far as possible, for the wavelength there is an optimum one when the indexes of contrast and resolution of the system are both considered. All of these methods can minimize the optical aberrations. Several numerical simulations demonstrate the method.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 60378018 and 60578026.
文摘The dynamical equation of a trapping cell is solved to find calibration methods for the trapping force, and two methods are compared by synthetic experiment data. Results indicate that： Boltzmann distribution method （BDM） is available for the force calibration of non-spherical or anisotropic cells in arbitrary trap potential; the mean square displacement method （MSDM） is available only for a symmetric harmonic optical trap. The spatial resolution requirement of the calibration system is about a nanometer. The results agree with the reported experiments.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 50175107. X. Chu's e-mail address is kejdcxc@sohu.com.
文摘A new direction recognizing and subdividing method for moire (interference) fringes is presented. By setting two certain thresholds, counting errors caused by direct voltage excursion are avoided. Counting and direction recognizing are discussed in detail. Experimental results are given. The better adaptability and large subdivision number are the good quality of this method.
基金the National Natural Science Foundation of China(No.60577029)the Natural Science Foundation of Hebei Province (No.F2008000750)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality,PHR(IHLB)
文摘Based on the point spread function of holographic system, the lateral resolution of digital holographic imaging system without any pre-magnification is studied. The expression of resolution limitation of holo-graphic imaging system is thus presented. We investigate the possibilities to improve the lateral resolution. The simple experimental setup with an off-axis arrangement is built. By using a U.S. Air Force （USAF） test target as microscopic object, the recorded holograms are reconstructed digitally based on the principle of Fresnel diffraction. The lateral resolution of 2.76 μm without any pre-magnification is demonstrated experimentally, which matches the theoretical prediction well.
基金supported by the National Natural Science Foundation of China under Grant Nos.61205019and 61475150
文摘We present a method of time coding with ABAB synchronization timing control for real-time 3D superresolution range-gated imaging （3DSRGI）. To meet the high precision of time delay and pulse width in ABAB synchronization time sequencing, phase shift is implemented to achieve ns-scaled delay and width accuracy without restoring to high clock frequencies. Theoretical analysis and experiments prove that 1 ns delay and width precision is obtained by our timing control unit based on a single field-programmable gate array with 5 ns clock cycle. Finally, a prototype experiment of 3DSRGI is demonstrated at a 10 Hz video rate with 696 pixels × 520 pixels.
基金supported by the National Natural Science Foundation of China (No.61378064)the National High Technology Research and Development Program of China (No.2015AA020510)
文摘Compared with binary diffractive super-resolving elements, programmable super-resolution pupil filters permit the analysis of various filter designs and allow the filters to be changed rapidly to modify the response of an optical system. In this Letter, a deformable mirror is employed as a programmable super-resolution pupil phase filter. Continuous phase-only filters based on the Zernike polynomial series are designed by the genetic algorithm and fitted through closed-loop adaptive optics with a piezoelectric deformable mirror. Experimental superresolution results are in agreement with the theoretical predictions. This method has no polarization light requirement and is convenient for application.
基金This work was supported by the National "863" Project of China (No. 2002AA313030)the National NaturalScience Foundation of China (No. 60207005)theScience and Technology Committee of Shanghai (No.022261045, 03QG14057)
文摘A novel read-only memory （ROM） disk with an AgOx mask layer was proposed and studied in this letter, The AgOg, films sputtered on the premastered substrates, with pits depth of 50 nm and pits length of 380 nm, were studied by an atomic force microscopy. Tile transmittances of these AgOx films were also measured by a spectrophotometer. Disk measurement was carried out by a dynamic setup with a laser wavelength of 632.8 nm and a lens numerical aperture （NA） of 0.40. The readout resolution limit of this setup was λ/（4NA） （400 nm）. Results showed that the super-resolution readout happened only when the oxygen flow ratios were at suitable values for these disks. The best super-.resolution performance was achieved at the oxygen flow ratio of 0.5 with the smoothest fihn surface. The super-resolution readout mechanism of these ROM disks was analyzed as well.
文摘The spectroscopic data recorded by dispersion spectrophotometer are usually degraded by the response function of the instrument. To improve the resolving power, double or triple cascade spectrophotometer and narrow slits have been employed, but the total flux of the radiation decreases accordingly, resulting in a lower signal-to-noise ratio （SNR） and a longer measuring time. However, the spectral resolution can be improved by mathematically removing the effect of the instrument response function. Based on the ShalviWeinstein criterion, a Gauss-Newton based kurtosis blind deconvolution algorithm for spectroscopic data is proposed. Experiments with some real measured Raman spectroscopic data show that this algorithm has excellent deconvolution capability.
基金This work was supported by the Fund of Dean of Info Science and Engineering College, Zhejiang University.
文摘Many approaches for high-resolution image reconstruction have been proposed in some literatures. One of the most commonly ways is to reconstruct a high-resolution image from a number of rotated and translated images with low resolution. In this process, the exposure difference among original images will decrease the quality of the reconstructed image. In order to remove the influence of the exposure difference, a light energy matching method is proposed in this paper. The theoretical analysis is illustrated in details. Experimental results show that the theoretical analysis is correct and the proposed method is valid.
