Design And Research On The Pyroelectric Imaging And The Image Post- Processing

With the development of application television in various industrial fields, infrared television is being more widely used than before. Therefore a set of pyroelecetric imaging system with indispensable technologies are required to come forth.The objective of this design is to incept and convert the object's infrared radiation distribution into video signal to be displayed in real time after being post-processed. Based on the plentiful research on the characteristics of pyroelectric vidicon imaging and infrared rays, a system framework is constructed. The framework consists of liquid crystal valve modulator, infrared lens,pyroelectric vidicon,pre-amplifier,timing circuit, auxiliary power supply circuit, video encoder,pedestal current generator and image post-processing module etc. In the experiment process ,individual modules are improved and enhanced.And two sets of schames, which lead to generate CVBS corresponding to the object's infrared radiation and to work stably and permanently,come into being. Morever,the liquid crystal valve chop-modulation can replace the traditional mechanic chop modulation ,and the pyroelectric image can be created by the pyroelectric vidicon.Based on designing and debugging the individual sub-modules, in order to realize the infrared image's enhancement display ,a integrated image post-process system is constructed. With the gray-slicing algorithm and the VHDL procedures employed, the color look-up table corresponding to different gray thresholds is configured. Hereby a pseudo-color processing system is implemented containing the video decoder SAA7111,CPLD EPM7064, video encoder SAA7185 and MCU 2051. Experiment proves that combining the intensity slicing algorithm and the hardware circuit presented here, the pseudo-color processing ,which is adaptable to varieties of circumstances, can be successfully realized.