Sudeep, P.V.Issac Niwas, S.Ponnusamy, P.Rajan, J.Xiaojun, Y.Wang, X.Luo, Y.Liu, L.2026-02-052016Computers in Biology and Medicine, 2016, 71, , pp. 97-107104825https://doi.org/10.1016/j.compbiomed.2016.02.003https://idr.nitk.ac.in/handle/123456789/26036Optical coherence tomography (OCT) has continually evolved and expanded as one of the most valuable routine tests in ophthalmology. However, noise (speckle) in the acquired images causes quality degradation of OCT images and makes it difficult to analyze the acquired images. In this paper, an iterative approach based on bilateral filtering is proposed for speckle reduction in multiframe OCT data. Gamma noise model is assumed for the observed OCT image. First, the adaptive version of the conventional bilateral filter is applied to enhance the multiframe OCT data and then the bias due to noise is reduced from each of the filtered frames. These unbiased filtered frames are then refined using an iterative approach. Finally, these refined frames are averaged to produce the denoised OCT image. Experimental results on phantom images and real OCT retinal images demonstrate the effectiveness of the proposed filter. © 2016 Elsevier Ltd.Adaptive opticsImage acquisitionImage enhancementMaximum likelihoodMaximum likelihood estimationNonlinear filteringOphthalmologyOptical tomographySpeckleTomographyAdaptive bilateral filteringAdaptive versionsBilateral filteringDe-noisingIterative approachQuality degradationSpeckle noiseSpeckle reductionAdaptive filtersArticlebilateral filteringcontrolled studydensity functional theoryimage processingmathematical parametersmaximum likelihood methodnoise reductionnonhumanoptical coherence tomographypriority journalquantitative analysisretina imagespeckle noisedeviceshumanimaging phantomproceduressignal noise ratiotheoretical modelHumansImage Processing, Computer-AssistedModels, TheoreticalPhantoms, ImagingSignal-To-Noise RatioTomography, Optical Coherence