基于FPGA的实时图像增强设计

Real-time image enhancement based on FPGA

局部直方图均衡是以全局直方图均衡化方法为基础,对图像中每个像素点所在的邻域范围求出灰度转换函数,然后仅应用在该中心点处。为了提高算法的运算速度,特别是在处理视频图像时,采取传统的DSP的设计方法在速度上很难满足需要,因此,利用FPGA实现是一个很好的选择。为使局部直方图均衡方法能够在FPGA上具体实现,从空间域的角度改进了图像灰度直方图均衡算法,并利用VHDL语言对算法进行了完全可综合的RTL级描述,最后在硬件平台上验证了结果。

Local histogram equalization is a technique commonly used in image enhancement,and it is based on global histogram equalization.In the algorithm,the gray converting function obtained in the neighborhood of one pixel is implemented at the pixel.For increasing the speed of processing, especially for the processing of video or image,it is an optimal choice to implement FPGA because DSP based technique can not meet real-time processing requirement.For the specific implementation of this algorithm on FPGA,some improvements over the traditional algorithm are made.The RTL-level description of the algorithm by VHDL language is achieved.The result was validated on hardware.