Speckle Filter | ![]() |
SAR images have inherent salt and pepper like texturing called speckles which degrade the quality of the image and make interpretation of features more difficult. Speckles are caused by random constructive and destructive interference of the de-phased but coherent return waves scattered by the elementary scatters within each resolution cell. Speckle noise reduction can be applied either by spatial filtering or multilook processing.
The operator supports the following speckle filters for handling speckle noise of different distributions (Gaussian, multiplicative or Gamma):
Reference:
[1] J. S. Lee, E. Pottier, Polarimetric SAR Radar Imaging: From Basic to Applications, CRC Press, Taylor & Francis Group, 2009.
[2] G. S. Robinson, “Edge Detection by Compass Gradient Masks”, Computer Graphics and Image Processing, vol. 6, No. 5, Oct. 1977, pp 492-502.
[3] V. S. Frost, J. A. Stiles, K. S. Shanmugan, J. C. Holtzman,
\A Model for Radar Images and Its Application to Adaptive Digital
Filtering of Multiplicative Noise", IEEE Transactions on Pattern
Analysis and Machine Intelligence, Vol. PAMI-4, pp. 157-166,
1982
[4] Mansourpour M., Rajabi M.A., Blais J.A.R., “Effects and Performance of Speckle Noise Reduction Filters on Active Radar and SAR Images”, http://people.ucalgary.ca/~blais/Mansourpour2006.pdf