An interesting algorithm for increasing the resolution and size of digital images is presented in this work. The proposed method preserves the image quality and allows one to upscale it, obtaining high-resolution and high-quality images. This method is very useful because efficient upscaling of single images acquired by low-grade sensors to high-quality, high-resolution images is a difficult problem. Most natural images contain both local regularities and discontinuities that can produce undesirable artifacts when scaling up the images.

Freedman and Fattal state that their method is better than some other recent well-known algorithms proposed in the literature because it produces more visually appealing images. Another important advantage is that it can be executed in real time, over both images and video sequences, using a parallel implementation on a graphics processing unit (GPU).

The authors propose using only local self-examples (extremely localized region samples) of the input image to create filter banks with a gradual upscaling process (small consecutive scaling factor adjustments). The main advantage of this method is that one can apply it in real time, since it uses only the original image as input. The fact that it is based on local self-examples allows one to obtain very efficient implementations in a GPU parallel version. Additionally, according to the authors, the quality of the obtained images is comparable to those obtained using other state-of-the-art algorithms, with the advantage that it outperforms the others.

The tests that the authors have conducted demonstrate that the final images usually do not suffer from the side effects of upscaling (such as artifacts, staircasing, or blurring). Interested readers can view these images on the authors’ project Web page [1].