基于MTF理论的遥感图像复原

Restoration of Remote Sensing Images Based on MTF Theory

由于遥感图像成像过程中受传感器性能下降、大气扰动等因素影响,致使图像质量退化。为了改善遥感图像质量,从图像质量退化原理分析,提出了一种基于调制传递函数(modu lation transfer function,MTF)理论的图像复原方法。该方法主要包括去噪和MTF拉伸两部分。针对遥感图像的特点,给出了一种有效的基于频域的去噪方法。为了能够调节频谱拉伸的程度,还给出了一种指数调节MTF曲线的方法。中巴(中国和巴西)卫星红外遥感图像的实验结果表明:该新方法有效地提高了图像的对比度(对于实验图像来说,较复原前图像对比度提高了7倍多,方差也由原来的8.77提高到17.37)、熵等图像要素,从而改善了图像的质量。

Due to the effect of a sensor, atmosphere etc, remote sensing images are degenerated. To improve the quality of remote sensing images, this paper proposes an image restoration approach based on the modulation transfer function（MTF） according to the analysis of the image degeneration theory. Our method mainly includes two parts： denoising and MTF compensation. An effective denoising method on the frequency space is presented according to the characteristics of remote sensing images. An exponent adjusting method of MTF curve is presented to adjust the MTF compensation degree. The experimental results with CBERS images proved that our method is effective to improve the image factors, such as image contrast, entropy etc, so as to compensate degenerated images.