基于边缘的实时图像缩放算法研究

传统的基于图像边缘的插值算法由于自身的复杂性而很少用于实时图像处理,而不基于边缘的插值算法由于低通滤波的效应通常会使插值后的图像出现边缘模糊,影响视觉效果。针对上述问题,提出了一种基于边缘的自适应图像插值算法。该算法以相邻像素的二阶差分为基础,自动选择与目标像素点相对应的源像素组进行插值运算。在Matlab环境中实现了各种图像插值算法,然后对插值结果进行了主客观评价,并对各种算法获得的图像进行了边缘检测及复杂度分析。同时,设计了本文算法的硬件实现结构,并用Verilog语言进行描述,综合出目标代码,最后通过FPGA验证。研究表明,运用该算法插值获得了边缘清晰的目标图像,且该算法复杂度低,便于硬件实现。因此,该算法能有效地实现图像插值,适应于实时条件下的图像缩放。

Edge-based Algorithm of Real-time Image Resizing

Due to their complexity,traditional edge-based algorithms of image interpolation are hardly used for real-time image processing.And non-edge based interpolation algorithms usually lead to the target images blurring because of their low-pass effect,so the visual effect of the interpolated images is unpleasant.In this paper,a novel adaptive edge-based algorithm of image interpolation is proposed to eliminate the defect.According to the second-order difference of the consecutive pixels,the source pixel group is automatically selected to compute the corresponding target pixel gray value.Several algorithms of image scaling are implemented in Matlab.Then the visual appearance and the edges of target images are compared,and the complexity of the algorithms is analyzed.The implementation circuit architecture for our proposed algorithm is devised and the algorithm is realized by Verilog HDL.Finally,the synthesized code is verified by downloading to FPGA on the evaluated board.The results show that our proposed algorithm achieves vivid edges of target images,and has lower computation complexity and easy for hardware implementation.So the algorithm can effectively interpolate images and adapts to real-time image resizing.