为了有效抑制激光主动成像中的散斑噪声以及保护边缘细节信息, 提出一种基于同态滤波和改进阈值整数提升小波变换级联的散斑噪声抑制方法。首先,使用同态滤波将乘性散斑噪声变为加性噪声, 然后使用整数提升小波变换进行分解; 再次, 在分析经典阈值方法存在不足的基础上, 设计了一种新的阈值函数模型以及自适应阈值计算方法, 并对小波分解系数进行阈值处理; 最后, 进行小波系数重构和同态逆变换, 得到去噪后的图像。仿真实验表明, 该算法能够有效抑制噪声, 同时能够较好地保护图像的边缘, 具有较强的实用性。

To suppress speckle noise effectively and protect edge details, a method for speckle noise suppression is proposed based on homomorphic filtering and the improved threshold integer lifting wavelet transform.Firstly, the homomrphic filtering is used for converting the multiplicative speckle noise into additive noise, and the integer lifting wavelet transform is used to decompose the image.Then, according to analysis to the shortcomings of the traditional wavelet threshold function, a new threshold function model and an adaptive threshold calculation method are designed, and threshold processing is made to the coefficients of the wavelet decomposition.Finally, inverse wavelet transform and inverse homomopgic transform are carried out and the denoised image is obtained.Simulation experiments show that the proposed algorithm can not only suppress the speckle noise effectively, but also protect the edges properly, thus it has good practicability.