FPGA-based adaptive Butterworth filter for color images and its applications

Traditional Butterworth filter cannot adaptively adjust the cutoff frequency for different images, in view of this problem, the proposed frequency adaptive two-dimensional Butterworth filter, through the high frequency band energy in the total image energy ratio, adaptively adjust the cutoff frequency. The color space used is Hue-Saturation-Intensity(HSI), and the data format replaces the fixed-point number with a floating-point number, achieving high-speed, high-precision 2D-Fast Fourier Transform(FFT) and 2D-Inverse Fast Fourier Transform(IFFT). Deeply considering the underlying structure of Xilinx 7 series Field Programmable Gate Array(FPGA) hardware, the filter is implemented on the xc7a100tfgg484-3 chip, and on this basis, the image details are enhanced, and the image color is colorless and the image details are richer. The hardware simulation results show that the image with a resolution of 512×512 takes 6548.892 μs to complete a 2D-FFT, which is 99.9998% similar to the spectrum structure calculated by software. The entire design trade-offs between resources, power consumption, and performance.