High Dynamic Image Synthesis Technology Based On SCMOS

As a low-light detector,s CMOS has developed rapidly and received extensive attention in recent years.With the advantages of high sensitivity,low power consumption,low readout noise and good readout speed,it became an important sensor type in the field of low-light detection.In addition,sCMOS can also obtain different exposure images synchronously by adjusting the gain,which lays a solid foundation for the wide application of sCMOS in the field of rapid high dynamic synthesis.In this paper,based on the technology of real-time high dynamic range imaging,we carry out the following tasks:Firstly,based on the ISE platform,the existing image acquisition programs are analyzed in the context of FPGA as the control chip.The simulation test and verification of the main modules are carried out.The acquisition and control of the image can be realized by using a serial port assistant without the use of the software with the development board.In addition,the image output mode of Camera Link interface is designed by ourselves.When the different gain is set,the high and low gain image of the common acquisition card can be displayed at the same time.Secondly,combined with the idea of piecewise linear correction and least squares method,we propose a piecewise linear interpolation algorithm based on the least square method.Since any type of image sensor has a different degree of non-uniformity.And when the gain value is set larger,not only the useful signal but also the noise is amplified.Therefore,for the sCMOS sensor to work more effectively,the non-uniformity correction is necessary.The experimental results show that the correction method proposed in this paper has a good performance in the entire illumination range.And this method can be adapted to different degrees of non-uniformity correction.Moreover,the average uniformity can be increased by about 40% in our experiment.And the corrected LDR image contains less noise,which provides a guarantee for the high quality of HDR composite images.Thirdly,in order to acquire the high dynamic range images,our subject has conducted a lot of research on the technology of high dynamic image synthesis which based on the methods of image fusion.Considering the gray characteristics of the sensor's dual gain channel output image,we propose a fast high dynamics image synthesis method in view of double gain characteristics.Referring to the objective image quality evaluation criteria,our method has a better synthesis effect than the same curve-fitting method based on the sCMOS sensor.In addition,we also designed the algorithm based on hardware implementation framework.Experimental results proved that this algorithm can achieve real-time high dynamic range image acquisition.