Some novel combining approaches to reduce speckle noises

In the optical test and measurement, speckle noise is a commonly noise which spoils the quality of the optical images, therefore, how to eliminate this kind of noise and keep the high frequency detail is an important subject, there have been presented many approaches such as adaptive median filtering in space domain, low pass filter in frequency domain and wavelet based approaches. Different filter has its own advantage and disadvantage, some filtering method is complicated and inconvenient for practice application. And the wavelet-based methods usually blurred the image. Therefore to find a simple and robust filtering method is valuable and important for speckle reduction. In this paper on the bases of theory analysis and simulation, an approach which combines the advantage of wavelet analysis, adaptive median filtering and Gauss filtering technique have been presented. The de-noising effect is evaluated with Signal to Noise Ratio (SNR), The simulation results demonstrate that the combining de-noise approaches are better than single method.