Abstract: For the motion estimation problems of image super-resolution，a two-step estimation method is proposed to estimate relative motion parameters between low-resolution images.Firstly，a certain method such as correlation-or distance-based method is used to estimate integer-pixels shift parameters between two images，one of them is then compensated to aligne to another.Secondly，the gradient-based method is used for the aligned images to estimate fraction-pixels shift parameters between them.Through the two estimation step，the accurate motion parameter is obtained at high speed without interpolating the low resolution images.

摘要： 针对图像超分辨中的运动估计问题，提出了一种两步估计方法，用于估计低分辨图像帧间的子像素相对运动。第一步，采用相关法或匹配法计算两幅低分辨率图像间的整像素相对位移，对其中的一幅按估计的参数进行运动补偿，第二步，对补偿后的两幅图像使用梯度法计算小数像素相对位移。通过两步计算，得到了比较精确的帧间相对运动参数。该方法不需要对低分辨率图像进行插值，以获得图像的高分辨近似，运算速度也较快。