1. A method for converting an image for displaying on a display surface, comprising the steps of: storing in a memory at least a portion of a video formed by a plurality of frames, wherein a frame of the video is an input image; scaling the input image to generate a foreground image, in which a content of the foreground image corresponds directly to a content of the input image, and in which a resolution of the foreground image when displayed is smaller than a resolution of a display surface; transforming the input image to a background image, in which a content of the background image depends indirectly on the input image, and in which a resolution of the background image is larger than the resolution of the foreground image, wherein the transforming comprises: downsampling the input image to generate a downsampled image having a resolution less than 5×5 pixels; and upsampling the downsampled image to generate the background image; combining the foreground image with the background image to form an output image, in which pixels of the foreground image replace corresponding pixels of the background image; and repeating the scaling, the transforming, and the combining for all frames in the plurality of frames stored in the memory producing a plurality of output images, in which every output image is produced from a time-wise corresponding input image such that the plurality of output images forms an output video, wherein the scaling, the transforming, and the combining are performed by a processor.