Stochastic noise damper for remote sensing CCD camera black level

Abstract

The invention discloses a random noise attenuator of a black level of a remote sensing CCD camera, which comprises a time schedule control module, a filtration correction module and a black level attenuating module, wherein the time schedule control module controls the filtration correction module and the black level attenuating module to carry out digital filtering processing to digitally-quantized CCD black level signals through judging that external rows are synchronous, so as to achieve the goal of attenuating the black level random noise and obtain the maximum resolution and dynamic range of the image. As processing is carried out by aiming at quantized digital signals, black pixel multi-channel sharing can be realized, thus leading other channels to be capable of sharing true black pixel resources contained only in a certain channel, breaking through the restrictions of exclusive use for single channel and extending the application range; the number of the black pixels can be changed by allocating instructions, the attenuator can be applicable to CCD devices of different types, and can achieve different filtering effects by setting different filtering factors, with strong applicability and flexible usage.

Description

technical field The invention relates to a random noise reducer, in particular to a dark level random noise reducer based on IIR filtering of a remote sensing CCD camera. Background technique Due to the existence of factors such as dark current, the CCD signal quantization output gray value is not zero under completely no light conditions, which has a great impact on the imaging quality of aerospace remote sensing cameras under low light. In order to eliminate this part of unnecessary bias and obtain a larger image dynamic range, almost all types of CCDs will output a varying number of dark pixel signals, that is, CCD dark levels, which generally appear at the beginning of the CCD signal. Or the position of the end of the line, as a reference for subsequent signal processing, that is, only the CCD signal after removing this part of the black level bias is the real response to the input optical image. Slow changes in light intensity, temperature, and power supply voltage wi...

AI Technical Summary

Problems solved by technology

This analog correction method can effectively reduce the dark level, but its disadvantage is that it must be dedicated to each channel, that is, it can only be operated on the dark level of this channel. If the dark pixel of a certain channel is missing or not When there are real dark pixels, this method cannot be used to effectively eliminate noise

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