夜间成像光测数字图像增强技术研究

分析夜间成像的光测数字图像灰度范围、对比度和信息量等主要特点，为图像增强的策略选择和效果评价提供依据。针对夜间成像光测数字图像灰度范围较窄等特点，提出局部灰度修正的增强方法适当增强图像对比度，又避免细节损失，同时，利用拉普拉斯锐化突出目标轮廓和边缘，并利用人眼对彩色敏感的特点，采用伪彩色增强提高对图像中模糊目标的分辨能力。通过上述3种增强技术，提高了对夜间成像暗图像的目标识别能力，有利于后续判读处理。

Study on Optical Measurement Digital Image Enhancement during Imaging at Night

The main characteristics, e.g. gray level range, contrast and entropy, in optical measurement digital images shot at night are analyzed. Algorithms for image enhancement and its effect evaluation are based on the characteristics of these images. A new algorithm for dark image enhancement based on local gray level modification is proposed. This algorithm enhances image contrast and maintains the detail at the same time. In addition, the images are sharpened with Laplace transform for edge enhancement, and the distinguishability for blurred objects in the dark image is improved with artificial color technology. The recognizability of images is increased with the three image enhancement techniques. This significantly benefits subsequent image interpretation.