Power-Efficient VLSI Architecture of a New Class of Dyadic Gabor Wavelets for Medical Image Retrieval

Abstract

Gabor wavelet is widely used in the analysis of texture features. It is found that Gabor wavelet filter bank (FB) requires infinite precision (due to irrational coefficients) to extract accurate directional textural features for which it needs numerous computations and external memory access. Due to this, there is a requirement for huge digital hardware, increased dynamic power dissipation, and increased processing time. In order to solve these issues, this article presents the first dyadic Gabor wavelet FB (DGWFB) based on the slight alteration in orientation parameter without disturbing the remaining Gabor wavelet parameters. In addition, this article introduces a separable VLSI architecture for the proposed DGWFB. The proposed VLSI architecture is implemented in field-programmable gate array (FPGA) through Xilinx Kintex 7 platform. It is observed that the proposed DGWFB has reduced processing time, dynamic power dissipation and digital hardware requirement significantly. The effectiveness of the designed DGWFB is evaluated in medical image retrieval application using three different publicly available medical databases namely NEMA, OASIS, and EXACT09. The proposed DGWFB achieved better performance as compared to existing Gabor wavelet FBs with significantly reduced digital hardware and processing time.