Study On The Method And Realization For Nonuniformity Correction Of Image Sensor

Nowadays the human being has come into the information age. It becomesresearch focus how to get the information. However, the mass information more than80% is got by visual organs. As a type of basic device of getting visual information theimage sensors are developing fast with the increasing development of technology ofsemiconductor integrated circuit and are utilized widely in many fields such as civil use ,militariness ,astronomy ,medicine , industrial detecting ,automatic control and so on. But any type of image sensor has the question of nonuniformity. This question willdirectly affect the quality of image and image sensor's using range. As a result, it is verynecessary to research this question and find a method to resolve this question. Firstly, the thesis introduces the principle of nonuniformity and the imagingcharacteristics. On this condition, the thesis brings forth the method which linearizecharacteristic curve of photoelectric conversion of image sensor by several segmentsand the principle and algorithm of nonuniformity correction. At the same time, thethesis also put forward the design scheme which integrates data-sampling, analysis andprocessing, controlling, Digitl-to-Anolog conversion as well as data-communication. Itallows the system to satisfy all demands of the correction effectively and stably. Secondly, the thesis introduce the design of hardware platform whose control coreis high density programmable logic device (HDPLD), which consists ofAnolog-to-Digital Convertor, Digital-to-Anolog Convertor, HDPLD, Micro-ControllerUnit (MCU),memory and so on. Thirdly, the thesis discusses the design of correction software which includes MCUprogram, HDPLD program and C language program on PC. The CL512J CMOS imagesensor which is produced at the Chongqing University is used in the nonuniformitycorrection experiment. In the course of the experiment, the PC is used to realize thecorrection algorithm and analyze the index of performance at first. Then the correctionsystem operates singly and realizes the nonuniformity correction of CL512J. Theexperimental result shows the nonuniformityof CL512J decreases from more than 45%to less than 2%.It is seen that the correction system has stable performance and can be II重庆大学硕士论文 英文摘要flexibly updated and easily extended. Finally, the thesis analyses how to use the correction system to realize thenonuniformitycorrection of image sensors of other type in principle.