Speckle reduction in optical coherence tomography images based on wave atoms

Area of Science:

• Biomedical Imaging
• Signal Processing
• Image Analysis

Background:

• Optical Coherence Tomography (OCT) is a noninvasive imaging technique utilizing low-coherence interferometry.
• Speckle noise in OCT images significantly degrades image contrast and quality.
• Existing denoising methods may introduce artifacts or lack optimal performance.

Purpose of the Study:

• To propose and evaluate a novel speckle reduction filter for OCT images using wave atoms transform.
• To enhance the quality and contrast of OCT images by effectively removing speckle noise.
• To compare the proposed method against traditional wavelet and curvelet thresholding techniques.

Main Methods:

• A shrinkage filter based on the wave atoms transform was developed for speckle reduction.
• Cycle spinning technology was integrated to ensure translation invariance and minimize visual artifacts.
• An adjustable parameter controlled the speckle suppression threshold in the wave atoms domain.

Main Results:

• The proposed wave atoms transform method effectively suppressed speckle noise in OCT images.
• Quantitative metrics including signal-to-noise ratio, contrast-to-noise ratio, and cross-correlation (XCOR) showed significant improvement.
• The method demonstrated superior performance compared to wavelet and curvelet thresholding techniques.

Conclusions:

• Wave atoms transform offers a powerful tool for speckle reduction in OCT imaging.
• The proposed denoising scheme effectively enhances OCT image quality without introducing significant artifacts.
• This technique holds promise for improving diagnostic accuracy in OCT-based applications.