As diode laser processing for different processing technologies demands different power densities and spot sizes, this paper researched how to get focus spot outputs with different sizes by adjusting optical path design to meet the requirements of various laser applications. By using ZEMAX to simulate the diode laser optical path, including beam shaping, collimation, focus, etc., several kinds of spot outputs with various sizes was implemented. In the experiment, a 980 nm diode laser stack with the superposition of 16 bars was used by a threshold current of 6.4 A, the maximum operating current of 84.8 A, maximum output power of 1 280 W, and the total electrical-optical conversion efficiency of 58.9%. After collimation, the divergence angles for the fast axis and slow axis are less than 4 mrad and 20 mrad, respectively. Finally, the experiments were performed on the diode laser stack by the beam shaping, collimation and focusing, and a power output of 1 031 W is obtained. Furthermore, the focused spot size has been 1.2 mm × 1.5 mm and the laser power density is up to 3.8×104 W/cm2 when the focal length of focusing mirror is 300 nm. Results show that the laser stack can be used in remelting, alloying, cladding and thermal conductivity-type welding for metal surfaces.

The stereo mapping precision of mapping cameras depends on the calibration precision of the geometric parameters, such as inner orientation parameters and distortion, therefore, a new calibration method of inner orientation parameters and distortion for a three-mirror off-axis Time Delay Integration(TDI)CCD camera was proposed. The optical system and image plane stitching of the camera were introduced, and the meanings of the inner orientation parameters and distortion were defined. A calibration system and corresponding mathematical model were established, then the expressions of inner orientation parameters and distortion were settled by the least square poly-regress method. A calibration experiment was performed on the camera, and results show that the point calibration accuracy and the focal calibration accuracy are better than 1.0 μm(1σ) and 2.0 μm(1σ), respectively.Moreover, the distortion calibration accuracy has been 2.3 μm(1σ). Obtained results demonstrate that the calibration method has the advantages in the speed and efficiency for three-mirror off-axis TDICCD cameras.

In a dual Mach-Zehnder fiber interferometric sensing system, the high locating accuracy is hardly obtained due to the discrepancy of two detection signals resulting from polarization fading. To keep the stability of the detection signals, a method to control the polarization fading was proposed in this paper. A optical polarization model was established to analyze the origin of polarization fading in the system. It points out that the basic reason for the discrepancy of the detection signal correlation is from that the inconsistency of the polarization characteristics between two sensing fibers results in the effect of the input polarization on detection signals. Based on the analysis, the solutions of controlling the input polarization and searching for the working points of polarization state were put forward to eliminate the polarization fading. Furthermore, the requirements of polarization control were further determined by analyzing the relation between signal correlation coefficients and two parameters of input polarization, and simulated annealing was applied to the verification of this theory. Field test results show that the algorithm can make a fast search for the working points of polarization state, and can maintain a steady signal correlation. It is proved that the polarization fading control method is feasible and effective.

To meet the requirements of large aperture optical elements for high precision manufacturing, a 3-axis Computer Numerical Control(CNC) milling machine was reconstructed into a 5-axis CNC one to implement the hardware improvement. The reconstructing process from the 3-axis machine to the 5-axis one was introduced, and a method to calibrate the parameters of the tool spindle was put forward. The method used a higher precision laser tracker to build coordinate systems, collect data and calculate geometric parameters, then to obtain the calibrating results of the rod length and swing angle for the tool spindle. Precision analysis shows that the angular precision is better than 10.000″ and the length precision is better than 0.040 mm. The proposed method can also be applied to similar tasks.

To support the correct design of cryogenic optical systems, a measuring system for the detectivity of infrared detectors in low temperature background was established and applied to some infrared detectors for testing their detection characteristics. First, the theoretical analysis for noise and response characteristics of an infrared acquisition system was introduced, and the relationship between the design of a low temperature optical system and the detectivity of infrared detector in the low temperature background was established. Then, a measurement system of detectivity in the low temperature background based on thermal vacuum enviroment was proposed, and experimental research on some infrared detectors in the low temperature background was accomplished. Finally, the variation regularities of limiting integration time and detectivity in low temperature compared with those in normal temperature case were discussed as well. Experimental results indicate that both of the integration time and detecitivity in the low temperature background are 20 times that in normal temperature background. The regularity derived can satisfy the requirments of system index design of low temperature optical systems.

As the surface shape of a reflection mirror is different from the target shape at the end stage of the grinding process, and the profilometers and common interferometers can not measure the surface error exactly, this paper proposed a method to measure the large aperture aspheric surface by using a Shack-Hartmann Wavefront Sensor (SHWS) with a large dynamic range and high precision. The principle of the measuring system for SHWS was researched, its measuring errors were analyzed and a corresponding data processing software was compiled. Using a simulation reference file, a hyperboloid reflection mirror with a diameter of 350 mm was tested by the SHWS. Results indicate that the PV and RMS of the surface error are 0.388λ and 0.043λ, respectively (λ=632.8 nm). In order to testify the measurement result, the mirror is also measured by an interferometer with a null compensator. Comparing the two testing results, the PV and RMS of the deviation are 0014λ and 0001λ, respectively, which proves the feasibility of measuring large aperture aspheric surfaces by SHWSs.

When a Hartmann-Shack(HS) wavefront tester is used to test lenses with high numerical apertures, the spherical reference wavefront from nanometer pinholes should be taken to calibrate the H-S sensor. To fabricate a high quality pinhole, this paper analyzes the factors affecting the quality of reference wavefront to obtain the optimal parameters of the pinhole. The vector diffraction of the pinhole is calculated based on the vector diffraction theory, the effect of the thickness, diameter of the pinhole on the diffraction wavefront errors is analyzed and the aberration, power transmission, intensity uniformity, fabrication errors and incident light with shift, defocus and tilt are discussed under a converging Gaussian incident light. The calculation and analysis show that in order to obtain a reference wavefront with a numerical aperture 0.6 and a peak-to-valley(P-V) value below 0.005λ(λ=193 nm), the best choice for the pinhole is the material chromium with a thickness of 200 nm and a pinhole diameter of 180 nm.

A boiling heat transfer test unit was designed and built. The TH5104 infrared thermography was used to measure the wall temperature of a microtube to research the characteristics of boiling heat transfer of refrigerant in the microtube. The test piece was a single stainless circular tube with an external diameter of 1.22 mm, an internal diameter of 0.86 mm and a length of 200 mm. The infrared photography was used to test and record the wall temperature of the microtube with heat flux ranging from 65 kW/m2 to 231 kW/m2 at different mass fluxes from 1 726 kg/m2·s to 8 635 kg/m2·s. Experimental results indicate that the wall temperature distribution along the axial direction has a regular change obviously. For the flow boiling in the horizontal microtube, a large temperature difference along the whole tube is shown during the evaporation of fluid in the microtube. Whether the difference of wall temperature is positive or negative,it is relative to the heat flux. The variation of the wall temperature is affected by the heat flux, flow patterns of working fluid and the heat transfer model,and the more complex the flow pattern is, the more severe the wall temperature varies.

With the aim to improve the unified performance of the first soft X-ray spectromicroscopic beamline built in Shanghai Synchrotron Radiation Facility(SSRF), This paper analyzes the main factors that effect the light spot transversal transfer of the spectromicroscopic beamline during wavelength scanning by a variable-included-angle plane grating monochromator. It deduces the relation between various factors and light spot transversal transfer, and solves the error distribution of the system to ensure the performance of the beamline. A test system for the repeatability of light spot transversal transfer is built by auto collimation principle and the off-line testing of the light spot transversal transfer is finished by using this test system. The result shows that the repeatability is 0.67″, which satisfies the technical requirement of 1″. The unified performance for the beamline is tested after it is assembled. Obtained results meet the requirements of design and application, and prove the effectiveness of error analysis and testing for the light spot transversal transfer.

The influence of the optical properties of aerosols on polarized sky radiance was researched to obtain the actual polarized sky radiance distribution model. Using the polarized sky radiance measuring system set up by ourselves, a lot of experiments were done at the same place but different dates. The degree of polarization and polarized sky radiation were acquired through these measurements in the solar altitude angle about 60° and the scattering of 90° for three wave bands of 435-465 nm，535-565 nm and 685-715 nm. The aerosol optical depth was calculated by theory formula according to atmospheric pressure and visibility. When the aerosol optical depth increases from 0.2 to 0.55, the degrees of polarization for the three different wave bands decrease separately from 43% to 22%, 41% to 21% and 38% to 19%, but the radiation shows a trend of increase. Experimental results indicate that as the increase of aerosol optical depth, the degree of polarization will decrease, especially more significantly reduction for the longer wavelength. Therefore, the increase of aerosol optical depth is not conducive for the navigation according to polarized light.

The spherical reference in a vertical Fizeau interferometer was calibrated by the two-sphere method to identify the surface deformations induced by gravity, mounting or holding forces to improve the surface measurement accuracy of optical elements in vertical optical systems. First, the algorithm of two-sphere absolute method was deduced. Then, the factors that may influence measurement accuracy, including environment, gravity, mounting or holding forces were analyzed in theory or calculation by simulation. Finally, the spherical reference used in the vertical Fizeau interferometer was calibrated by two-sphere method, and the experimental results were analyzed by the law of error combination. Experimental results indicate that the calibration accuracy by using two-sphere method is 2.3 nm RMS for the spherical reference of F/15 vertical Fizeau interferometer. Among them, the measurement repeatability induced by the method and experimental operation is no more than 0.7 nm, and that is no more than 1.2 nm while environment influences are taken into account, including vibration and temperature. Furthermore, the surface deformation induced by gravity is about 0.9 nm RMS, and that induced by mounting or holding force is about 1.7 nm. In conclusion, two-sphere method is high precise method that can be used in calibrating vertical spherical reference and the influence of environments on measurement is relative to the length of interferometric cavity. The spherical reference must be calibrated before it is used for high precise measurement vertically, for the surface deformation will be remarkable induced by the gravity, mounting or holding forces.

A 3D transient model was established based on the theories of fluid dynamics and heat transfer to analyze the fluid flow and the heat transfer characteristics in the liquid pool when a pulse laser was used to weld the Hastelloy C-276 alloy. On the basis of software Fluent, the Finite Volume Method (FVM) was employed to solve the control equations and the algorithm of SIMPLE was adopted to deal with the coupling of velocity and pressure. The Pe number was induced to evaluate the relative importance of convection and conduction then to analyze the heat transfer characteristics of welding pool. The research indicates that fluid flow velocities along the welding direction in the liquid pool increase with the increasing of the distance from the melting pool center, and then decrease. Under the given conditions, the maximum flow velocity is firstly found at the 0.2 mm from the melting pool center, then it reduces to zero rapidly and velocities in front of the melting pool along the welding direction are slightly larger than that of in the rear ones. Furthermore, The convection leads the melting pool to wider and shallower and the interaction of convection and conduction decides the final weld joint morphology. The numerical simulation is in good agreement with the experimental results, Which proves that the model can provide a theoretical basis for the analysis of the fluid flow in the weld pool during pulsed laser welding thin Hastelloy C-276 alloy.

A flexible locomotion system is proposed to improve the active locomotion ability of gastrointestinal microrobots in the minimally invasive diagnosis. The locomotion system simulating inchworm-like locomotion comprises a flexible locomotion mechanism and a drive mechanism. The flexible locomotion mechanism is mainly composed of radial balloon feet and an axial telescopic pushrod. In addition, a developed universal joint is used to join two cavities of the microrobot to improve its locomotion flexibility. The drive mechanism uses the nylon wires to actuate the bellows bump for the balloon feet and stimulate the telescopic pushrod for the microrobot to realize the flexible drive. The developed microrobot prototype shows its diameter in 12.2 mm, length in 78 mm and the weight in 14.8 g, and realizes the maximum clamping diameter of 20.2 mm and the maximum axial stroke of 16 mm. The experiments show that the wire drive mechanism can provide the maximum force of 067 N for the bellows bump and 065 N for the axial pushrod, respectively. The microrobot prototype can move in the rigid plexiglass tube with different angles, and the average speeds in the horizontal and vertical tubes are 0.38 mm/s and 0.25 mm/s, respectively. In addition, it can move in the curving plastic tube with a minimum curvature radius of 49.3 mm and present an effective locomotion in vitro intestinal tract. It can be seen that the flexible locomotion system provides an effective and safe locomotion case for gastrontestinal microrobots.

To increase the stabilization and reliability of piezoresistive pressure sensors working in harsh environments with harsh acids, alkalis, corrosive salts, and other destructive substances such as electrostatic particles and damp, a novel piezoresistive pressure sensor was presented. The innovation of the sensor was that the sensing elements of the sensor were fabricated in the lower surface of a silicon diaphragm and were sealed in a vacuum pressure cavity by silicon-glass bonding process. The work principle of this pressure sensor was introduced. Then, Finite Element Method and ANSYS soft were used to simulate the stress distribution of the diaphragm. Finally, the micro-electro-mechanical System(MEMS) technology was used to fabricate a pressure sensor with the dimension of 1.5 mm×1.5 mm×500 μm. The measurement results by a pressure test platform show that the sensitivity of the sensor is about 20 mV/V-MPa, and its maximum nonlinearity is 2.73% FSS, which meets the requirements of the modern industrial applications.

A thermal control system for space cameras was designed according to its space environments and structure characteristics. Firstly, the thermal design guidelines of space cameras were summarized, and the thermal environment of a space camera was analyzed. Then, the thermal design of the space camera was carried out. By utilizing the thermal capacitance of a satellite, the passive thermal control was used for thermal isolation and thermal transmission and the active thermal control was conducted to implement the temperature compensation. Finally, four extreme test conditions were designed and thermal balance tests were undertaken according to various work patterns and different thermal environments. The test results show that the temperature difference is 3 ℃ between the space camera and the fitting surface, which meets the system requirements for storage work conditions. Furthermore, the whole space camera temperatures are -3.1 ℃ and 45.7 ℃, the lens temperatures are -4.5 ℃ and 46.8 ℃ in the low temperature and high temperature work conditions, respectively, and they meet the thermal control system requirements. In conclusions, the thermal design of the space camera is feasible and reasonable.

As rotor imbalance can lead to the synchronous disturbances of Magnetically Suspended Control Moment Gyroscopes (MSCMG), and can reduce the attitude control accuracy and the load accuracy of spacecrafts, A general control strategy based on a sliding mode disturbance observer was proposed to minimize the synchronous vibration caused by unbalance on a rotor. First, a dynamics model of the magnetic bearing-rotor system was set up and the sliding mode observer used for disturbance observation was designed. Then, a Tracking Differentiator (TD) was used to estimate the differential signals from a displacement sensor to obtain the velocity signals and to reduce orders of the observer. Finally, according to the synchronous force estimated by the disturbance observer, a controller was designed to compensate the vibration caused by unbalance of the rotor. Simulation and experimental results demonstrate the effectiveness of the proposed approach and the vibration has been decreased by 72%.

For demands of optical systems in a off-axis three-mirror camera on the optical-mechanical structure, an appropriate optical-mechanical structure was designed by taking Carbon Fiber Composite(CFC) as the key components of the camera. The weight of CFC in designed camera makes up 32% that of the total system. Furthermore, this optical-mechanical structure is asymmetric, the system spacing in the primary, secondary mirror is 850 mm, and the mirror positioning accuracy demands its interval, eccentric and tilt to be 0.005 mm, 0.005 mm, and 5″, respectively. The Finite Element method was used to analyze and optimize the design, results show that the optical-mechanical structure has better stiffness, lighter weight, and can meet the requirements of optical system for intervals, eccentrics and tilts. A mechanics environmental test and a thermal vacuum test were performed, and results demonstrate that the optical-mechanical structure in the camera has excellent stability in mechanics, thermal and other environmental conditions, its first order harmonic frequencies are above 120 Hz, and the modulation transfer function is more than 0.2. These results prove that the proposed structure can provide reasonable spatial location and stability for the reflective mirrors in off-axis three-mirror cameras.

A systemic approach to the structure synthesis of fully-isotropic three degree-of-freedom(DoF) planar parallel manipulators was presented. Firstly, the necessary conditions for designing fully-isotropic planar parallel manipulators were discussed by use of the screw theory. Based on the different control functions of each limb for the moving platforms, the actuation screw, actuated screw and mobile unactuated screws of every limb were derived in terms of the reciprocal screw theory. Then, all possible limbs were enumerated according to the different connectivity numbers of the kinematic chain. Finally, the desired manipulators, including 3 167 new types, were obtained by connecting the moving platform to the fixed base by using three limbs according to some assembling conditions. Each kinematic Jacobian of these manipulators is an identical matrix and their conditioning numbers are all equal to 1, so the manipulators can offer very good motion and force transmissions, and show prospective applications in industrial robots, micro-manipulating robots, and medical robots.

An online identification neural network model and an adaptive controller were designed and verified by simulations to inhibit the influence of hysteresis, creep and dynamic characteristics of a piezo-stage on the positioning accuracy. First, the double Sigmoid activation function was adopted to improve the activation functions of neural networks, and the similarities and differences between improved neural work model and PI hysteresis model were analyzed. Then, a BP neural network with three layers based on the improved activation function was designed as the online identification model of piezo-stage, and the correction formulas for the network weights, thresholds as well as the activation function thresholds were derived. Finally, the adaptive control scheme of the piezo-stage was proposed based on the online identification neural network model, which made use of another neural networks to complete the parameter adjustment of an adaptive PID controller. Experimental results show that the average error and the maximum error are 0.095 μm and 0.32 μm for the online identification neural network model, 0.070 μm and 0.100 μm for the adaptive control scheme on tracking triangle waves, and 0.080 μm and 0.105 μm for the tracking multiple frequency wave, respectively. Obtained data prove that positioning accuracy of the piezo-stage is improved effectively.

In order to improve the dynamic performance, load capacity and the bandwidth of a piezoelectric amplifier, a high-voltage power amplifier based on multi-unit cascade was developed. First, a high-precision amplifier unit based on discrete components was designed and a series of models for every driving units were simulated. Then, the stability of the amplifier unit in a piezoelectric capacitive load was analyzed and a effective dual-channel feedback compensation strategy was given. Furthermore, based on multi-unit floating cascade topology, a novel combined high-voltage piezoelectric amplifier was developed by cascading the multiple independent high-precision piezoelectric amplifier unit. Experimental results indicate that the cascade amplifier can offer the output voltage amplitude of 0~1 000 V, maximum output power of 1 kW, large signal bandwidth over 1 kHz/0.3 μF, and the static ripple of 100 mV. It concludes that the amplifier can satisfy the system requirements of low ripple, high accuracy, large bandwidth, short response time and good load capacity.

A new vertical spindle supporting system was presented to improve the stiffness of an aerostatic bearing and to meet the requirements of machine tools for aerostatic bearings. The Computational Fluid Dynamics (CFD) and Finite Volume Method (FVM) were used for simulating the flow field and pressure field inside the aerostatic bearing and for researching its static characteristics. The grid subdivision in the direction of film thickness was implemented while establishing the grid of the gas film. Finally, a 2 μm/grid on the thrust surfaces and 2.5 μm/grid on the radial surfaces along the film thickness direction were achieved. Results indicate that the gas velocities around the orifices are about 200 m/s and 1 m/s when the pressure distribution of the gas film is changed and the loading capacity is achieved 3 508 N/μm. It concludes that the static characteristics of the aerostatic bearing can be improved by increasing supply pressures or decreasing the diameters of orifices.

The work performance of key components in an underground drilling turbine generator for the Logging While Drilling(LWD) were researched. First, a kind of high performance hydraulic turbine model was established. Then, the turbine model with different blade parameters were studied in the turbulent flow field based on the Computational Fluid Dynamics(CFD ) theory by using the Fluent software. The effects of flow rates, rotational speeds on the turbine flow field were analyzed. Finally, the relationship of flow rates, rotational speeds, loads and turbine generator output voltage were verified through a ground one-way water conservancy experiment for the turbine generator. The simulation analysis results show that the turbine model with 15 blades, import blade angle above 30°, export angle below 45°, the arc radius of 40 mm or less has excellent hydraulic performance, however, the higher hydraulic efficiency will reduce the working life of the turbine. It suggests that improving the efficiency of hydraulic turbines by increasing the flow and speed should be controlled in a certain range. The established turbine model improves the output power of the turbine and ensures its working life.

An automatic measurement system for low frequency noises is established to sort solar cells according to their reliability. First, according to the sources of the 1/f noise of a solar cell, this paper identifies the feasibility of 1/f noise under big current density to be the reliability indication of the solar cell. Then, according to the noise spectral character measured by the automatic measurement system, it points out that comparing the 1/f noise spectrum of different solar cells in f at 1 Hz is an effective method to distinguish the reliability of different solar cells. Finally, the method to determine the threshold of screening solar cells is given based on the standard of semiconductor device quality classification. Experimental results indicate that this kind of method can nondestructively sort the solar cells into three groups according to their reliability, and spends only 5 min for measuring single solar cell. The proposed method can detect every single solar cell correctly and has advantages over traditional methods in costs, time and hard to be hurt. This method can satisfy the application requirements of screening solar cells for high reliability.

An error control coding method is proposed to improve the reliability of serial data transmission for the display information of a LED large screen remote communication system. Considering the difference of the hardware basis and the implementation requirements between a transmitter and a receiver, a parallel algorithm structure is presented at the information transmitter，and the generating coding matrix is deduced to improve the real time performance of the coding algorithm. Moreover, a dual clock serial circulation decoding structure is presented at the information receiver, in which the high-speed clock after serial syndrome computation is used to correct the error bit to allow the long codeword to obtain a low hardware overhead and real time processing ability. Practice and theoretical analysis shows that the designed scheme can accomplish a high effective coding in efficiency of 98.2%, and can reduce the bit error rate effectively at least 1 order of magnitude in the application. The scheme can achieve high efficient serial transmission of display information.

To reduce the effect of large number of invalid data in fringe patterns on calculation results in the measurement of high dynamic flows using interferometry or Moiré deflectometry, an effective phase extraction method was proposed based on the wavelet transform using complex Morlet wavelet. Through choosing proper parameters for the wavelet, the maximum modulus of the wavelet transform of a pattern was proportional to its modulation factor, then it was used as a weighting factor of a phase unwrapping algorithm based on weighted least squares to guarantee reliable phase unwrapping. In the process of wavelet ridge routing, a simple algorithm based on curve fitting was proposed to substantially reduce the routing time and the precision deterioration due to image noise. In simulation experiment, the relative error between calculated phase and actual phase is less than 0.01%. In internal wave measurement experiment, the method is used to analyze the fringe patterns, and the density gradient measurement precision has reached 5×10-6 g/cm4. It shows that the method can reduce the effect of invalid data on analysis precision effectively and can obtain reliable unwrapped phases.

As the Harris detector can produce false and unstable corners, and obtained matching points have different accuracies in aerial video registration, an aerial video registration algorithm using optimal gradient filters and projective invariant was proposed. Firstly, a Harris detector based on optimal gradient filters was presented to determine the location of corners, and the locally most stable points were selected to be matching points. Then, the Delaunay triangulation was used to perform the initial matching. Finally, the most "useful" matching points that best satisfied the cross-ratio invariant were presented to estimate the geometry transformation and finish the image registration . Experiment results show that the proposed method by the optimal gradient filters and cross-ratio invariant can realize the registration between the frames, and the average geometric fidelity error is 0869 for 8 sets of the unmanned video sequences with a resolution of 320 pixel×240 pixel. The method can capture moving objects effectively.

For the inherent misregistration between the two sets of spectral bands and its effect on the spectral purity of each pixel hyperspectral imagery, a sub-pixel image registration method was proposed based on the characteristic of the hyperspectral imagery. Firstly, band selection and principal component transformation were used to process the Visible Near Infrared (VNIR) and Short Wave Infrared (SWIR) spectral bands, and the first principal component was chosen as the input image. Then, the input image was evenly divided into the image block with a certain overlap rate. Furthermore, the phase correlation method was taken to estimate the sub-pixel motion and the phase correlation coefficient was used to remove a few mismatches in the correlation output and to generate an optical flow field. Finally, the spectrometer images were registered by the calculated optical flow filed. Experimental results show that the accuracy of registration is superior to 0.1 pixel, which meets the accuracy requirement of advanced image processing.

A lossless compression algorithm based on contents was proposed for hyperspectral images. An adaptive band selection algorithm was introduced to reduce the dimensionality of hyperspectral images, and a C-means algorithm was used to classify the spectral vectors resulting from dimensionality reduction unsupervisedly. Then, the reverse monotonic ordering method was taken to determine the prediction ordering, hyperspectral images were divided into groups adaptively according to the correlation between each adjacent bands, and the scheme of multi-band linear prediction was used to eliminate the spectral redundancy of the identical class. For each class, partial pixels within this class were selected to train optimal predictive coefficients, and predictive errors were compressed in lossless by JPEG-LS standard. Experiments were performed for the hyperspectral images acquired by an Airborne Visible/Infrared Imaging Spectrometer(AVIRIS) and an Operational Modular Imaging Spectrometer(OMIS). Experiental results show that the average compression ratio of the proposed algorithm can be improved about 0.11 and 0.7 respectively as compared with above algorithms without classification prediction.

An efficient stereo fractal video coding based on pre-searching was presented for the stereo video coding successfully. The basic stereo fractal video coding was improved by using tree structure macroblock partition, Discrete Cosine Transform(DCT) based encoding for original frame, reducing block searching range and computational repetition in advance. In stereo fractal video coding, the left view video was arranged as a main view and the Motion Compensation Prediction(MCP) was taken as coding structures by employing pre-searching limitation condition, improved UMHexagonS motion estimation algorithm, deblocking loop filter and sub-pixel block matching. The right view video was arranged as an enhanced view, the MCP and Disparity Compensation Prediction(DCP)were combined to be as coding structures, and the matching block with smallest matching error was chosen as the estimation results. In the DCP coding, a fast disparity estimation algorithm was proposed by making full use of disparity distribution restriction conditions. Experimental results indicate that the compression time by proposed stereo fractal video coding algorithm is 18%-23% that by the basic stereo fractal video coding algorithm, and the compression ratio has improved by 15.13-47.49 while a proper Peak Signal Noise Ratio(PSNR) is maintained . These results show the compression performance of the stereo fractal video coding algorithm and its applications are more flexible and practical.