The Research On Drive And Image Preprocess Of Uncooled Infrared FPA

Uncooled infrared focal plane array(FPA)has become a primary option for many portable infrared systems because of its small size,low power consumption,low prices and some other advantages.Also,it has been applied wildly to military and commercial products.Concerning its manufacturing technology and principle of operation,the working state of uncooled infrared FPA can be easily affected by its working condition.Meanwhile,the inevitable non-uniformity and low contrast ratio in infrared imaging make it harder to exact useful information from infrared image,so measures must be taken to improve the outcome of the system.Based on laboratory's self-made UL03162 uncooled infrared camera,this study mainly focus on figure out the influence,which the drive and image preprocess of uncooled infrared camera system have on the finial infrared image,by studying correction and image enhanced algorithms,and presents solution to those problems.Firstly,this paper introduces the hardware structure of the uncooled infrared camera system,and illustrates the feasibility of the system to generate infrared image by analyzing the performance of then sensor,the storage and calculation of the system.Some vital chips that have close relation to the implementation of the algorithms and experiments are also introduced,including its main function.Secondly,this paper introduces the initialization of the sensors.By analyzing time sequence of the sensor and A/D,we designed the initialization parameter,pulse signal and synchronic signal according to the standard we set at the beginning.At the meantime,we figured out the effects that voltage ripple and the value of sensitive voltage have on the infrared image,so we designed filter circuit according to the voltage ripple,and calculated the range of the usable voltage to obtain better voltage parameters that suit for wilder temperature range.Thirdly,to solve the non-uniformity problem of the uncooled infrared FPA,we compared two points and one point correction algorithm.By taking the RMS(root mean square)of the outcome image as evaluation standard,we chose the better algorithm and calculated its correction coefficients.To deal with low contrast ratio,we summarized the histogram's characteristics of the infrared image and compared several mainstream algorithms based on histogram.Then we proposed an improved algorithm based on histogram and transplant it into hardware successful.Finally,we confirmed the instability of temperature would bring bad effects on FPA,so we figure out the relation between the image gray level and the temperature of the FPA through experiment,and compensate parameter from different temperature can be obtained and put into use for real-time.Also,to make the image' parameter more audio-visual and to make every test more convenient,we designed a program for computer to communicate with the camera system,which makes data transforming easier and manipulation more simple.