Another factor was that the precision was strongly related to the interpolation method, which in the case was bicubic interpolation.
Bicubic interpolation : another interpolation method used in our experiments is bicubic interpolation.
Using a Gauss map algorithm described elsewhere, the method is implemented in the context of bicubic Bézier surfaces, and applied to the problem of minimizing the greatest scallop height incurred in contour machining of surfaces using a 3-axis milling machine with a ball-end cutter.
This method is hardware method.
Thus, if we set the initial estimated HR image as the Bicubic interpolated one of the initial LR frames, the HR image result obtained with the proposed method cannot be worse than the Bicubic interpolation result even though most of the LR data are excluded.
To improve the mass conservation performance of the coupled level set method, a bicubic interpolation is combined with the Fast Marching Method for level set re-initialization on quadrilateral grids.
Thus, a simple bicubic interpolation method may be sufficient to properly produce an HR image from a single LR image with minimal noise and blur.
From the results we can see that, when the scale changes are small, our method and Bicubic spline interpolation out-perform the rest of the methods.
When comparing the bilinear and the bicubic interpolation we hardly notice any difference apart from a slightly sharper appearance in case of the latter method (may be attributed to the edge-preserving property in case of this method).
The LR-SNN-T method [11] is based on an equalization of the original image and a normalization of its dimension using a bicubic interpolation.
