结合频谱移位的二维傅里叶变换FPGA实现

Implementation of Two-Dimensional Fourier Transform Combined with Spectrum-Shifting Based on FPGA

在三维成像技术中,对图像进行傅里叶变换之后需要通过频谱移位将零频集中到中心位置。为了提高图像处理的运算速度,提出了一种结合频谱移位的二维傅里叶变换的FPGA实现方法,将频谱移位结合到二维傅里叶变换硬件系统中,在实现图像二维傅里叶变换的同时也完成了一半的频谱移位。采用ALTERA系列EP4CE115F29C7芯片,针对256×256的图像实现设计,最高工作频率分别达到84.2 MHz;资源消耗为3 849个LE。采用Signal TapⅡLogic Analyzer工具实时验证了模块的正确性。

In 3 d imaging technology,after the Fourier transform of the image zero frequency will need to be concentrated to the center position by spectrum-shift. In order to improve the speed of image processing,a method of the implementation of two-dimensional Fourier transform combining with spectrum-shift is proposed based on FPGA.Combing the spectrum-shift with the two-dimensional Fourier transform hardware systems,the two-dimensional Fourier transform of the image and the half of the spectrum-shift can be achieved at the same time. The Altera chip of EP4 CE115 F29 C7 was used in this design and the hardware implementation was completed for 256 × 256 of the image. The highest working frequency reached to 84. 2 MHz. The amount of the resource usage reached to 3 849 LEs. The SignalTap Ⅱ Logic Analyzer has verified the correctness of the module realtimely.