彩色图像的RGB 3个通道间具有密切的相关性.若将现有具有边缘保持作用的灰度图像超分辨率方法直接推广到RGB空间中进行,很容易破坏这种相关性,也必会导致色彩伪影.为解决此问题,本文提出了一种基于alpha 通道的彩色图像超分辨率方法.首先,对图像进行区域分割,并对每个区域进行前景、背景及alpha通道的提取;然后,将alpha通道、前景及背景图像分别进行超分辨率;最后,合成得到高分辨率图像.该方法基于图像分割和alpha matting技术,利用alpha通道协调3个通道的边缘信息.实验结果表明,该算法在较好地实现超分辨率的同时保持了图像的边缘,避免了色彩失真,具有较好的视觉效果.
There is a close correlation between the three channels of a color image. The existing edge preserving super-resolution method for grayscale image can not be extended directly to RGB space, because it is easy to break the relevance and cause color artifacts. A new method of color image super resolution based on alpha channel is proposed to solve this problem. Firstly, the image is segmented by region, and the foreground, background and alpha channel of each region are extracted. Then, the alpha channel, foreground and background images are super-resoluted respectively. Finally, the high resolution image is synthesized again. The alpha channel is used to coordinate the edge information of three channels. The experimental results show that the method can keep the color edge of the image better and has better visual effects.
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