A region of interest based approach for texture analysis of medical images in space–frequency domain

Publication date: May 2019Source: Biomedical Signal Processing and Control, Volume 51Author(s): Pyari Mohan Pradhan, Chun Hing Cheng, Joseph Ross MitchellAbstractThe two-dimensional S-transform (ST-2D) is a space–frequency representation (SFR) useful in image processing especially for texture analysis. The high computation time and inefficiency in computing the local spectrum at each pixel in an image motivated the authors to develop the two-dimensional fast time–frequency transform (FTFT-2D). However, in practice, the SFRs at individual pixels are seldom used for analysis. In most medical images, the spectral distribution over a region of interest (ROI) is of higher significance than that at individual pixels. This paper proposes a two-dimensional ROI-based fast time–frequency transform (FTFT-2D-ROI) for computing the average local spectrum and spectral statistics for an ROI faster and more efficiently using three skipping strategies. The spectral statistics for an ROI have been computed using mean and standard deviation of SFR magnitude in both Cartesian and polar coordinate systems. Simulations were performed with rectangular and non-rectangular ROIs while employing the three skipping strategies of FTFT-2D-ROI for a brain MRI image. Moving from skipping strategy I toward III, the computation time of FTFT-2D-ROI decreases significantly but at a cost of some degradation in accuracy of the SFR. The computational performance of the proposed FTFT-2D-ROI is also studied fo...
Source: Biomedical Signal Processing and Control - Category: Biomedical Science Source Type: research