Technologies Of Photoelectric Image Acquisition And Processing In Special Environment

The measurement of cannon static parameters is a prerequisite and importance technique process in studying, designing and using of modern cannon. The laggard measurement method based on optics glass and data processing artificiality can not satisfy new requirement that following progression of cannon development, manufacture level and using requirement. It is must to build high efficiency, precision, automatism measurement system. This dissertation studies on key technique such as photoelectricity imaging and image processing thoroughly in cannon static parameters measurement system that developed by us and based on laser collimation and CCD imaging.On foundation of lucubratting for measuring principle, measuring method and performance and limitation of the active furnishment about non-straightness of barrels and chamber parameters of cannon, the precept of non-straightness of barrels measurement system based on laser collimation and CCD imaging was presented and realized. Two aspects that photoelectricity image acquirement in the special environment and precision image measurement were studied as pivot. The scene state control in photoelectricity image and optical system precept for close quarters and fine definition imaging that based on special environment of cannon chamber were studied and designed. The precept and arithmetic of image pretreatment, image calibration and precision image measurement based on special image that acquiring were founded. These precept and arithmetic were application in the engineering development of cannon static parameters measurement system already that passed through theories studying and calculating machine simulate optimization and achieved the anticipative purpose. Main contents that studied in the dissertation was:1. Photoelectricity image acquisitiona. Contraposing the special imaging environment that is difficulty to imaging by general technique because complexity structure, surface smooth and clean, the complicated reflected ray in cannon chamber. The illumination distributing condition and corresponding environment was founded that the distinctly imaging request was founded by simulating imaging and image process technique. The illumination distributing environment that requiring by high quality imaging of CCD camera was founded by adopting separate cold lamp-house and through optical technique such as ray scatter, reflection, addition and compensate. And the illumination environment can adapt different cannon chamber and insure imaging best by adjust the collocate parameters of lamp-house.b. Studying the photoelectricity imaging thoroughly that requiring measurement system possess the special short distance and big angle of view in image information acquisition. Analyzing the primary factor and technique difficultness that effect imaging quality in special requirement. That is non-uniformity distributing of definition bringing by the limitation of depth of field of optical system. This difficultness was resolved by mathematics modeling and optimization. The MTF was founded by analyzing the principle of image sensor thoroughly. The resolution, depth of field and calibration of aberration of optics system was studied thoroughly and the mathematics model was founded insuring that imaging measurement system possess high space resolution. The technique that system possess high space resolution, big depth of field and small aberration synchronously was studied emphatically. Realize to acquire complicated image within cannon chamber with big angle of view, long depth of field, fine definition and high fidelity in special condition by design and control parameters such as focus length, size of diaphragm and structure size of optical system.2. Image process and measurementa. Studying and designing the precept and arithmetic of image pretreatment, image segmentation and image calibration by contraposing characteristic of acquiring image and special requirement by measurement system. A set of high efficiency arithmetic was presented by studying multifold image pretreatment arithmetic. It was proved by experiment could enhance image and preserve image detail that required by measurement at same time. The optimal precept of image segmentation that self-adaptive double threshold segmentation was established through studying multifold image segmentation arithmetic thoroughly. The image space process mainly involves concentric circle region self-adaptive parting, examining the concentric circle parameters, calibration the geometry distortion, ascertainment the centroid of laser spot.b. Studying arithmetic of high precision image measurement. Studying and designing arithmetic that departing first and then uniting by contraposing characteristic of measuring image is mixture of image and graph. That is detecting concentric circle and laser spot by sub-pixel and then calculate it unite. This arithmetic not only realized high precision image measurement, and furthermore, it achieved calibrating measuring data locale.The author not only designed and realized series arithmetic of special processing and high precision measurement for acquiring image, further more, the measure curve was created automatically by separate data formed by measurement was displayed on the screen of monitor straightforward. Otherwise, The badness effect to measurement that laser beam shift brings by transmission through air medium was analyzed and estimated.