Enhanced DVD conversion

[carlmart]

If we look at an HD image, 720p and 1080p, it looks less soft and with more detail. Obvious, of course.

We can do nothing for detail that was lost, but maybe we can do something to improve sharpness and other things.

Using Vidicoder to directly convert the DVD to MKV will produce an image with no enhanced border, which is very important.

The first image, on the beach, could help correct the general tone using the white walls. But I am not sure if there's correction tool that can do that.

The two interiors are the same image, paused in VLC. The one is at is, the second one has a little sharpen added.

Perhaps you can see other things that could be improved and suggest how.

The images are from a pass I did with Vidcoder, with standard setup. The DVD image looks much worst, but I can load them if you think is useful.

[LigH.de]

Regarding color "correction": Any kind of automatic feature (auto gain, auto white) would mess purposeful color shifts – just remember "The Matrix" which enhances green for virtual world scenes and reduces green for real world scenes. I believe it is more important to preserve correct colorimetry as long as it is known to be correct, by avoiding YUV/RGB conversions and flagging the material according to resolution and encoding. SD Material on DVD may usually be encoded with Rec.601 colorimetry, whereas HD video prefers Rec.709; but as long as there is no step involved there the video has to be represented as RGB, I doubt you have to convert anything regarding colors during your conversion. If anyone knows better, please explain...

Now, regarding resolutions: If you have real HD material, of course it looks sharper than DVD material when its source had a higher native resolution already. Upscaling SD resolution to HD will never restore lost resolution. You may increase sharpness artifically, but the result will always be artifical. Your mind will recognize it. Yet ... there are dumb approaches (anti-average matrix) and more elaborate techniques, like "Edge Directed Interpolation" while scaling the image to power-of-two factors of their original dimensions, before scaling it down to the desired target resolution.

[carlmart]

To start with you do not have to call anybody else to explain things better on color correction. I have edited several films in Avid Media Composer, and color corrected my stuff there, both in SD and HD.

When working there I would usually use white correction and black correction. Only once did I mix SD, upscaling it to HF using Avisynth. No problem with color standards.

And I also know HD looks sharper than SD. But I don't agree that increasing sharpness will make things look artificial if done carefully. The mind can be easily fooled, if you disguise things and know what you are doing. Hardware upscaling in more recent good BD players do a very good looking image from DVD discs.

But it seems I will have to take discussion to an Avisynth forum.

[LigH.de]

Well, AviSynth is not a wrong topic here. I mentioned EDI on purpose, we have e.g. NNEDI3 with the nnedi3_rpow2 function. This can be used to upscale by 2x or by 4x before downscaling. And in the middle, you could even add some kind of noise or dither to simulate some random "detail" (even if it is no comparison to original detail).

My personal experience is that artifical sharpening leaves some "plastic" impression to me. Probably because it was often a bit exaggerated, especially when in conjunction with heavy denoisers. It may be great for cartoons, but not so great for natural content. Less may be better in many cases.

I hope you will read more good ideas here.

[hello_hello]

It's not easy to see the whole story when looking at single pictures, but based on your screenshots the bottom pic looks a little too sharpened to me. I also try to avoid anything that enhances the noise, so I'd want to use some degree of noise removal before sharpening that one.

I agree with LigH.de. There's definitely a potential for the result to look a bit "plasticy" with too much noise removal and sharpening, although I dislike excess noise more so much of it's personal taste.

Personally I never "upscale" DVDs. Just resize to square pixel dimensions such as 654x480 or 1024x576. The upscaling used by most players/TVs these days is quite good. In fact often I resize them down a little if anything.

Maybe you could upload a small sample of video for others to process to their liking for comparison purposes. Still pictures can give the wrong impression.

[carlmart]

Probably no one can be more critical of plastic looks than me!

With HD I think we became more demanding. I myself come from film times, so film like is the look I look for.

Most sharpeners have to be softened somehow to look good, as well as denoisers. The last ones particularly I could never use in DVD times, as they did more harm than good.

But I was deeply surprised some months ago when I downloaded an Australian series in avi, because I couldn't find a better resolution file. It looked terrible on my computer monitor, but I didn't have any other option. My eyes widened when it went , via network, from my PC to my Mede8er media player, and from it to my 55" TV. I could see details that were not visible on the original!

[jagabo]

I don't know what the point of this thread is, but...

The upscaled images have bad aliasing artifacts. And the sharpened one is worse. nnedi3 plus a little sharpening would do much better.

Obviously, there are many tools to adjust colors, brightness, contrast, etc. But automatic levels and white balance tools usually don't work well for an entire video. Maybe for specific shots.

[carlmart]

Sorry, I forgot to explain that the lower photo is just a very crude example of sharpening done with Irfanview. Didn't touch anything else. Avisynth filters are enormously more subtle and effective. I wonder if I can use them with Vidcoder somehow.

The first two photos were upscaled using Vidcoder's setup, which I can show. If necessary I can capture the same images on the DVD.

The point of the thread is to find a way to try enhancing, different filters, that I will later use on a doc feature I shot in 2007, when consumer HD was barely available (with Sony Z1) and broadcasting still used SD. So I shot a few sequences in SD that I want to use.

Is there a way to use a video file with some test pattern that may tell us how the Mede8er media player is working, what it does?