The degradation of low-light-level image mainly depends on sensitivity,non-linearity and noise of detectors.

As the noise of low-light-level image can be removed efficiently and low-light-level image quality can be improved by low-light-level video real-time image processor, which has quality of super speed and real time, observation distance of low-light-level video observation system becomes far.

For the characteristics of infrared images for the target image focused on the distribution of gray,low-light-level grayscale image is relatively uniform distribution,a image fusion method is proposed in this paper,that is extracting infrared thermal targets firstly,and then fused to low-light-level image as the background.

Low contrast is one of the main characteristics of the low light level image, and contrast stretching is the important technical method to enhance the image.

A novel image enhancement technique suitable for low light level image, dualistic sub image enhancement based on two dimensional histogram analysis and histogram equalization, is presented.

Several optical methods of image differentiation;

Detailed information of an image can be obtained by optical image differentiation.

The calculation of the polymetallic nodule s grain size and abundance from deep-tow system s optic image;

Therefore a new technique to generate the grand based millmeter wave radiometric images from visual optic images was presented.