TMMI announced a new product last Friday called TRUPIX. It upscales video frames and offers several integer zoom levels, e.g. 2x, 3x, 4x, etc. They also have downloadable still images in BMP format showing how well TRUPIX performs.
I suppose that simply making such data available is a good sign. Before, the company was notorious for keeping all of their research and results hidden. Hopefully more transparency will be forthcoming, such as a detailed explanation of the upscaling algorithm.
The introductory image on the company’s website for TRUPIX could be construed as misleading: it shows a 540 pixel image on top of a 720 pixel image, and so on, each larger image showing successively more detail. One might be led to believe that the tiniest image can be upscaled to be as detailed as the largest. This, of course, is not the case.
Below are details of two of their example images: a motorcycle upsampled 4x. I chose an area that contains text as this is one of the hardest tests for any upsampler. On the left side is the original image upsampled 4x using a traditional bicubic algorithm, and on the right side is the same image upsampled 4x using TRUPIX.
The TRUPIX upsampling is noticeably sharper, but identical to long-existing technologies such as Perfect Resize and its predecessor, Genuine Fractals. Because the former can easily be configured to process multiple frames, there is little advantage to using TRUPIX. Perfect Resize is also a far more robust product including a full graphical preview system and many more filtering options. There are of course other products: Adobe Photoshop CC includes a “Preserve Details” option in its resampler, and Alien Skin offers their vectorizing upsampler BlowUp, etc.
The text in the image shows that no actual new detail is added to the TRUPIX image; it simply does the best it can with the pixels given to it. Edges are crisper, but the text does not resolve into perfect legibility. In technical terms, the information limits imposed by Shannon entropy are not overcome.
In the upper part of the image, the aliasing artifacts immediately below the white rectangle are not successfully smoothed. So the TRUPIX algorithm operates solely on local pixel areas and has insufficient knowledge of what the image is about in order to sharpen that region the way a human artist would.
To make matters worse, TRUPIX does not work in realtime but is instead an order of magnitude slower even when running on high-end equipment. So it cannot be used for live broadcasting, security applications, live surveillance, etc. In contrast, the existing digital zoom in one’s smartphone offers similar edge sharpening and easily records video in realtime.
Overall, TRUPIX is welcome in that TMMI is finally releasing something, but in practical terms, it is a textbook case of too little, too late. Is this what the company’s followers and investors have been waiting decades for?