【摘要】 因具备强大的细节刻画能力，双三次插值已成为图像超分中的常用算法.由于其借助在空间距离上与当前像素距离最近的16个像素构造插值基函数，故双三次插值本质上属于一种局部算法.这也意味着该算法的插值过程尚不能有效利用图像周期性(非局部性),从而致使其细节保持能力仍存在进一步提升空间.针对这一问题，通过对原插值基函数施加非局部权重修正，在一个更大范围内选取更多像素对当前像素的灰度值进行估计，实现了经典双三次插值算法的非局部拓展.在灰度图像和彩色图像两个不同场景上进行超分实验，主观视觉效果和客观量化指标均表明所提算法的有效性.更多还原

【Abstract】 Benefiting from its powerful ability in detail preseriving, bicubic interpolation has become a common algorithm in image super-resolution. The base function for bicubic interpolation is constructed by the 16 pixels that are closest to the current pixel in space, so the bicubic interpolation belongs to a local algorithm. This means that the interpolation process in this algorithm is not able to take advantage of the periodicity(non-locality)in natural images, and thus its performance still has room to be further improved. Based on this considerations, this paper introduces non-local weight correction into the definition of the base function to select more candidate pixels in a wider area to estimate the gray value of the current pixel. As a result, a non-local version of the typical bicubic interpolation is achieved. The experimental results suggest that it can reconstruct higher quality results both quantitatively and perceptually.更多还原