Real-time light leak phenomenon removing device for space and line space transfer CCD (charge coupled device) camera

Abstract

The invention relates to a real-time light leak phenomenon removing device for a space and line space transfer CCD (charge coupled device) camera, which comprises a device for collecting original image data sensed in effective pixel area of the CCD, a device for extracting the light leak signal numeral code in a dark pixel area of the CCD, and an image data correcting device, wherein the image data correcting device is used for correcting corresponding column data of the original image by utilizing the light leak signal numeral code extracted from the dark pixel area of the CCD, and the imagedata of which the light leak signal is removed can be obtained. According to the invention, the column data of the original image is corrected by utilizing the light leak signal numeral code extracted from the dark pixel area of the CCD, the calculated amount is small, the real time is good, and since the light leak signal can accurately stand for light leak charge of a high light area, the lightleak phenomenon is better removed without changing the CCD working conditions.

Description

technical field [0001] The invention belongs to the technical field of space cameras, and relates to a real-time light leakage elimination device for space cameras. Background technique [0002] With the rapid development of aerospace technology, large area array CCD cameras have become the main development direction of aerospace cameras due to their advantages of high resolution and large field of view. Among several area array CCD structures, the interline transfer area array CCD has the characteristics of no smear, fast transfer rate, and electronic shutter function. It is especially suitable for target acquisition and identification, resource exploration, geological surveying, etc., but in line During the work of the inter-transfer area array CCD, there will be light leakage, which will affect the image quality. [0003] Light leakage is a type of noise that occurs when a CCD image sensor transmits signal charges, and it is also noise specific to an area array CCD image...

AI Technical Summary

Problems solved by technology

[0005] 2. The light reflected and scattered at the edge of the opening of the photodiode, that is, the boundary of different refractive indices such as the surface of the Si substrate, enters the vertical CCD, and the charge generated here will also cause light leakage

[0006] 3. On the surface of the buried photodiode, the electrons generated in the P+ region diffuse on the surface, and the charge leaked to the adjacent vertical CCD will also cause light leakage

[0007] 4. Due to the defect of the AL film used for shading by the vertical CCD, the leaked light will also cause light leakage.

[0015] The disadvantage of this method is that when the digital value of the target area is high, and the digital value of the smear area or the background area is low, the average value is used to replace the light leakage signal, and some useful gray information will be lost.

[0016] Although the above two methods can play a certain role in suppressing the light leakage phenomenon, they cannot fundamentally eliminate the unique noise of this CCD device.

Moreover, for aerospace area array CCD cameras, when the camera orbit height and camera flight attitude are fixed, we cannot change the CCD pixel readout clock at will, nor can we change the CCD exposure time at will, and the method of reducing the exposure time will affect the CCD. image quality

Although the light leakage phenomenon can be eliminated through subsequent image processing methods, for large area array CCDs, subsequent image processing needs to open up a large amount of storage space, and the amount of calculation is large, which affects the real-time performance of the imaging system.

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