Image Sharpening Techniques & Plugins for Video Footage – Part II – Neat Video Denoiser
This is a continuation of a multi part series on image sharpening for video, in which the basics were covered in Part I. Read that here.
I’m going to just get down to it. Here are the sharpening contenders:
This is an organic idea I had when working on this writeup. Out of every noise removal plugin I’ve used this is by far my favorite. It also happens to integrate a post sharpen algorithm into the process. I’m not sure what kind of method it uses, but it allows adjustment of low/mid/high frequency sharpening and it provides a different kind of sharpness versus an unsharp mask.
This is an edge aware sharpening software plugin by Digital Anarchy that uses a number of algorithms along with GPU acceleration to provide a flexible way to sharpen video footage. The user can utilize masks to protect shadows and highlights, an example application being the ability to sharpen eyes and hair features while leaving the skin untouched. The kind people at Digital Anarchy provided me with a copy of the plugin for this purpose.
Pixelan’s plugin is another advanced sharpening toolkit with many user definable options. Allowing you to selectively sharpen parts of the image via organic masking, you can add that extra detail to the image where you like without having it come across as artifical, or drawing attention to sharpened noise. A second big thank you to Pixelan for providing a copy of the plugin.
I was originally creating one large article to put all of my info (and ramblings) into but I think it would be best to separate them out. I know the attention span on the internet is short so let’s just kick this Part II off with:
Neat Video Denoiser
While Denoiser is intended to reduce noise from video, and the best at it in my opinion, it also provides tools for post sharpening. For these tests I used NO noise reduction and only the sharpening features as to not skew the images. With almost all disciplines in the creative, a lot of it is subjective, and I will try to not preach what is best, but what I prefer and you can take it from there.
You can see with the unsharp mask, that the simple method brings out the noise in the darks as well as the details of the tiny hairs of the peacock feather. Neat Video sharpens the image in sections based on shadows/highlights (I did not use any noise reduction in the image) but leaves the noise alone which matches the raw image. Neat video also ups the contrast as the shadows become ‘chunkier’ for lack of a better word and brings out individual sections of color by increasing local contrast in the upper part of the image. I think the Neat Video result is a little harsh in this example but the ability to suppress sharpening of the noise is noted.
With this closeup of a woman’s eye, I actually prefer the overall neutral sharpening effect of the unsharpen mask. When compared to neat video, I think it looks more natural. Neat video seems to be determining areas to sharpen by localizing areas of contrast but in this case I think it makes the model’s folds in the skin around the eye seem deeper, and the specular highlights on the left of the eye too blotchy. Somehow unsharpen mask looks more flattering.
This example is a classic use of sharpening – to try to recover an out of focus shot. In this case I think I would again go with the classic unsharp mask. I’m not liking what the Denoiser plugin does as far as grouping sections of shadows and highlights, you can see some of the skin areas appear splotchy and lose the fine detail with unsharp mask. One of the upsides to Neat Video is it does appear to suppress some of the chromatic aberration present in the hair that unsharp mask worsens. I can accept the unsharp mask version as almost a grainy film that is underexposed which is more pleasing to my eye.
Neat Video Denoiser Sharpening Wrapup
So, Neat Video Denoiser. I do prefer it over unsharp mask in situations where noise levels are higher than normal as it avoids drawing attention to the noise, but seems to create unpleasantness when it comes to skin by creating a splotchy look. Neat Video does suppress the chromatic aberration from a lens while unsharp mask will make the problem worse.
Stay tuned for Part III, where the comparison will bring Digital Anarchy’s Samurai Sharpen to the table. Which has by far the coolest name of the three plugins.