The Design And Implementation Of A Space-variant Resolution Sensor System

Space-variant resolution sensor system utilizes the non-uniform sampling to compressthe redundant information of “non-interest” in the region, indirectly increasing thespeed of the subsequent signal processing. At the same time, the space-variantresolution sensor system can change the image in conventional Cartesian coordinatesto the image of log-polar coordinates, so that the rotation and scaling of the targets inthe Cartesian coordinates can be converted into the horizontal and vertical shift in thelog-polar coordinates, which can reduce the complexity in the object recognitionalgorithms and has an broad application prospects in the machine vision, imageprocessing and objects recognition and tracking.The conventional space-variant resolution sensor system based on CCD andCMOS technology has poor flexibility and resolution adjustment, complex signalreadout circuit, which is not conductive to the goal of rapid perception and tracking.Therefore, this thesis proposes a new space-variant resolution sensor system based on5×36non-uniform lens array, which is conductive to high speed, high sensitivity,flexible structure polar coordinate mapping imaging. The main research work doneinclude:(1) Based on the non-uniform imaging of human eye’s retina, we complete theoverall design of the space-variant resolution sensor system, which include thenon-uniform optical imaging module, CMOS imaging module, signal pre-processmodule, control and display module, etc.(2) Develop a non-uniform optical imaging module with5×36pixels, which canaccomplish the fuzzy perception of the target. This module include non-uniform lensarray, photo detectors array and signal readout circuit of it, completing the functionverification of the module.(3) Complete the design of CMOS imaging module mimics the human eye’scentral macular area. Verify the quality of output image, configuration of registersetting, Binning resolution adjustment, Bayer readout mode through the I2C serialdata protocol.(4) For the signal pre-processing demand of the non-uniform optical imagingmodule, this thesis design the signal pre-processing module which process the fivephoto current in parallel, which include the consistency correction and current-voltageconversion, signal amplification and analog to digital conversion. (5) Design the control and display module of the system, which include the datacache of the non-uniform optical imaging module and CMOS imaging module. Thismodule also drives the display with a VGA interface, showing the log-polar mappingimage of the non-uniform optical imaging module and CMOS imaging module.(6) Establish the experimental apparatus of the space-variant resolution sensorsystem, verify the function of non-uniform optical imaging module, CMOS imagingmodule, signal pre-processing module, control and imaging module and the rotationand scaling invariant of the system.Finally, this thesis realizes a space-variant resolution sensor system based onnon-uniform lens array of5×36pixels. The physical experiments and functionalityverification of each module are also conducted. The results lay a research foundationto obtain a high speed, high sensitivity flexible-structure space-variant resolutionsensor system.