多光谱成像系统会改变输出光的波长,这就导致图像在不同波段下形成了不均匀亮度(阴暗图像和高亮度图像),严重影响了特征波段提取与测量。为了提高各波段的有效利用率,引用了一种增强多光谱灰度图像清晰度的有效方法。通过非线性的偏微分方程扩大梯度空间、保留梯度值较大的边缘,增强图像的纹理细节。由于多光谱图像阴暗波段的纹理较弱,不容易辨别其所有信息,为了更好地使增强效果完全体现出来,使用直方图均衡化来调节亮度的不均匀性。最后,通过人眼视觉的定性和客观函数的定量两方面对该组增强图像的清晰度进行了评价。结果表明:该方法能够有效地协调各波段的多光谱图像清晰度,并且图像的增强效果也非常明显。

Multi-spectral imaging system can change the output wavelength of light well, forming the uneven brightness images in different wave bands(dark images and high brightness images), it will affect the extraction and measurement in the feature bands seriously. In order to improve the effective utilization of each band, this paper appoints an effective way to enhance multi-spectral gray-scale images′ sharpness. First enlarge gradient space through nonlinear partial differential equation, keep the bigger edges of the gradient value, enhance the texture details of images. Because the texture is weak in dark bands, to identify all of its information is difficult, to incarnate heighten and effect preferably, this article combines with the histogram equalization to adjust non-uniformity of brightness. Finally, evaluate this sets of enhanced images in two aspects by human vision qualitatively and objective function quantitately. The result shows that this method can coordinate multi-spectral images′ sharpness in different bands, and images′ enhancement effect is very obvious.