Footage looks too dark. Any way to color correct it?

[Sunk]

I have a sample from the movie "Trainspotting", recorded from TV back in the year 2000. I've noticed, however, that my capture looks noticeably darker than how the movie should actually look. Is there any way to tweak the colors so that they match the intended ones, even just a bit? I don't remember which VCR was used to originally record the movie, which TV and what kind of settings it had, I was still too young to memorize the details.

Attached are 2 samples: one from my capture and the other is from a clip on Youtube.

[jagabo]

In AviSynth something like this works ok as a rough approximation:

ColorYUV(gain_y=350, off_y=-10, cont_u=100, cont_v=100)

Alternatively, if you're more comfortable with brightness, contrast, and saturation, you can use Tweak:

Tweak(cont=2.4, bright=10, sat=1.4)

GUI programs usually have similar brightness, contrast, and saturation controls.

[Sunk]

In AviSynth something like this works ok as a rough approximation:

ColorYUV(gain_y=350, off_y=-10, cont_u=100, cont_v=100)

Alternatively, if you're more comfortable with brightness, contrast, and saturation, you can use Tweak:

Tweak(cont=2.4, bright=10, sat=1.4)

GUI programs usually have similar brightness, contrast, and saturation controls.

Thanks, already looks miles better than it did. The rest of the tape suffers from the same issue, not just the film. Are those settings universal or should I change values depending on the footage?

[jagabo]

The levels in the youtube video vs. your capture vary from shot to shot. I used a compromise setting that works ok-ish for most shots, but not are not optimal for each shot. It's up to you how much time you want to spend working on the video, tweaking every shot. It probably also needs some color adjustments beyond just an increase in saturation. And a lot of noise reduction.

[dellsam34]

I would not bother whith digitizing it when there is a better version with the whole frame instead of a noisy, dark and cropped to 4:3 frame. A Blu-ray version would be even better.

[Sunk]

I would not bother whith digitizing it when there is a better version with the whole frame instead of a noisy, dark and cropped to 4:3 frame. A Blu-ray version would be even better.

Yeah I know, but I've shown it mainly to demonstrate how dark the entire footage is, though I probably should've have chosen a different sample (or uploaded it alongside the Trainspotting one). Here's a sample from a TV commercial which was recorded on the same tape and it looks just as dark. Commercials have more value to me since a lot of them would never be rerun in the future and an upload doesn't always exist on Youtube.

[Leanoric]

I have the same problem, all of my captures are also too dark. You dont happen to be using an elgato do you?

[Sunk]

I have the same problem, all of my captures are also too dark. You dont happen to be using an elgato do you?

Nope, I use Matrox MXO2 LE.

[Alwyn]

I have the same problem, all of my captures are also too dark.

Are you setting the Proc Amp Brightness and Contrast before capture?

[jagabo]

Twix fix, plus white balance and noise reduction:

LWLibavVideoSource("twix.avi") 
Tweak(cont=2.1, bright=0, sat=1.0, coring=false)
vInverse()
ConvertToRGB().RGBAdjust(rb=-11, gb=8).RGBAdjust(r=249.0/219.0, b=249.0/166.0, gg=0.8, bg=0.8).ConvertToYV24()
SMDegrain(tr=3, thsad=1000, PreFilter=4)
ConvertToYV12()
prefetch(8)

[Leanoric]

I have the same problem, all of my captures are also too dark.

Are you setting the Proc Amp Brightness and Contrast before capture?

No I havent been. Ill give it a go on my next capture. Is there any advantage in adjusting the brightness and contrast pre capture as apposed to post processing?

[lollo]

Is there any advantage in adjusting the brightness and contrast pre capture as apposed to post processing?

If not doing so to stay inside capture range of your card, there are only disadvantages, because you act on a poor "digital base" of the procamp of the card and may create spikes and gaps, leading to banding and posterization.

In post processing you can achieve better results using dithering, etc.

[Alwyn]

Is there any advantage in adjusting the brightness and contrast pre capture as apposed to post processing?

I'll defer to the experts for a more technical explanation but IMO definitely Yes. You can maximise the brightness and contrast within the 15-235 range without over-darkening or over-whitening.

Using Virtual Dub in Capture mode, select the Histogram on the Video menu and it will/should appear below the video preview. Use the proc amp Brightness to control the left edge and contrast to control the right edge. Keep the edges just inside the red marks (Brightness can be a bit further left than the edge, but contrast will blow out the whites if over the right edge).

Sometimes pure defaults are OK, other times I've had to yank the contrast way up to get a decent histogram right edge.

The Histogram isn't the be-all and end-all of setting the levels, but it will be a good guide.

[Leanoric]

Ill give it a try but I dont think that Im going to be able to do it as the preview doesnt work for me in vdub, I think that it might be a windows 11 issue.

When I select 0 Microsoft WDM Image Capture (Win32) (VFW), I can see the preview window and whats playing on the vcr, but when I select the capture device that Im using the preview window disappears, so I dont think that Im going to be able to see the adjustments that I make.

[Alwyn]

In the Video menu, try choosing Overlay or Preview. One of those (depends on the digitiser) will display the preview window for me.

If you get that working and the preview window disappears when you go to Capture Filter (to get access to the Proc Amp tab), then set up Graphstudio. This will allow full access to the Proc Amp tab completely independently of Virtual Dub, and you'll be able to use the Histogram. You can even use it with AmarecTV (you won't have a histogram with it though) or any other capture program for that matter... did you say OBS???!!!!.

Graphstudio setup guide (source info from Jagabo):

https://drive.google.com/file/d/1DYxxRMdaVWF4nJpN_5_mbBKsnXcCoBlZ/view?usp=share_link

[Leanoric]

Thanks Alwyn. Ill have another go at trying to get the preview to work. I remember reading somewhere that a windows 10/11 update stopped it working for some people though. If not Ill download Graphstudio and do it that way.

[Barrythecrab]

If unable to get a view of your active capture in VDub...
Try activating histogram, enable/disable Noise Reduction in the menu.
I've not used W11 but I certainly had issues seeing the VDub preview.
Of course there is always AmaRecTV.

[Sharc]

Thanks Alwyn. Ill have another go at trying to get the preview to work. I remember reading somewhere that a windows 10/11 update stopped it working for some people though. If not Ill download Graphstudio and do it that way.

Did you ever inspect the histogram and waveform of your "too dark" videos? If they are not totally off the kilter (clipped or extremely crushed) you can correct a lot in post processing and save yourself the trouble of a re-capture and fiddling with "proc-amp" settings.
You can analyze histograms and waveforms with Avisynth or Vdub.

[Alwyn]

Try activating histogram, enable/disable Noise Reduction in the menu.

Where's the Noise Reduction, Barry?

[Leanoric]

Did you ever inspect the histogram and waveform of your "too dark" videos? If they are not totally off the kilter (clipped or extremely crushed) you can correct a lot in post processing and save yourself the trouble of a re-capture and fiddling with "proc-amp" settings.
You can analyze histograms and waveforms with Avisynth or Vdub.

Im not quite sure how to interpret them, they dont have the red markers like the ones that Alwyn mentioned.

[Leanoric]

Try activating histogram, enable/disable Noise Reduction in the menu.

Where's the Noise Reduction, Barry?

Its under swap fields in the video tab.

[Alwyn]

Thanks. Didn't even know it existed.

[lollo]

Im not quite sure how to interpret them

You're crushing the blacks (note the accumulation on the left side of your histograms). Tune the procamp to avoid it. This will also increase brightness.

A (almost) clean histogram is something like this:





And, once more , learn AviSynth and use it for a better understanding of the video properties

[Sharc]

Im not quite sure how to interpret them

You're crushing the blacks (note the accumulation on the left side of your histograms). Tune the procamp to avoid it. This will also increase brightness.

And, once more , learn AviSynth and use it for a better understanding of the video properties

Agree. His accumulation on the left of the histograms is biased by the black borders though. Nevertheless I would also suggest to re-capture with proper settings.
Here just a quick and dirty attempt of a fix of his screenshots:

[Alwyn]

My VDub histogram tute:

https://drive.google.com/file/d/1Tk9CHXNnfHgBJxCbQz4NeApfW0ZguSt2/view?usp=share_link

As alluded-to by Sharc, to get accurate levels, you should crop off all the black crud on the sides. Make sure you uncrop for the actual capture.

[jagabo]

I recommend you use waveform monitors instead of histograms. They are generally much more useful as they give an indication of where the problems are. AviSynth's Histogram() defaults to a waveform monitor. This write-up may help you understand them:

https://forum.videohelp.com/threads/340804-colorspace-conversation-elaboration#post2121568

Unfortunately, you can't easily use it while previewing in VirtualDub's capture mode. Trevlac's Color Tools in VirtualDub has a waveform mode you can probably use for capture preview. Unfortunately, it replaces the video with the waveform.


[Attachment 70685 - Click to enlarge]

[lollo]

I recommend you use waveform monitors instead of histograms. They are generally much more useful as they give an indication of where the problems are.

Yes, correct, Histograms are for a first summary inspection.

I also use Limiter() http://avisynth.nl/index.php/Limiter, highlighting the areas of interest.


[Attachment 70686 - Click to enlarge]

function f_limiter(clip c)
{
c_l=c.Limiter(16, 235, 16, 240, "luma_grey")
c_c=c.Limiter(16, 235, 16, 240, "chroma_grey")
stackhorizontal(\
c,\
stackvertical(\
c_l.BicubicResize(c_l.width/2,c_l.height/2),\
c_c.BicubicResize(c_c.width/2,c_c.height/2)\
)\
)
}

[Leanoric]

Unfortunately I cant get the preview window to work at all in vdub. The histogram still works though, I just cant see the picture, so with the help of Alwyns tutorial, I adjusted the proc amp settings with graphstudio. I didnt touch hue or saturation as I couldnt see what effect they would have. Capture looks much better now.

Nevertheless I would also suggest to re-capture with proper settings.

I wish that I'd asked about this sooner, I've captured about 50 hours of tapes with the wrong settings

And, once more , learn AviSynth and use it for a better understanding of the video properties

I recommend you use waveform monitors instead of histograms. They are generally much more useful as they give an indication of where the problems are. AviSynth's Histogram() defaults to a waveform monitor.

You guys will regret tempting me into downloading avisnth, I'll drive you mad asking even more questions than I already do

[Sharc]

Unfortunately I cant get the preview window to work at all in vdub. The histogram still works though, I just cant see the picture, so with the help of Alwyns tutorial, I adjusted the proc amp settings with graphstudio. I didnt touch hue or saturation as I couldnt see what effect they would have. Capture looks much better now.

Nevertheless I would also suggest to re-capture with proper settings.

I wish that I'd asked about this sooner, I've captured about 50 hours of tapes with the wrong settings

You may want to upload a sample of your new captures and collect comments, before spending time for capturing another 50 hours of tapes......

[Alwyn]

Leanoric, yes, I found that VDub preview window to be singularly the most annoying and temperamental aspect of using VDub and the main reason and now use AmarecTV (as well as sync). From what I have seen, it is dependent on the driver for the digitiser. I don't have any trouble at all on Win 10 with the GV-USB2, USB Live2 or the Startech USB3HDCAP, but the USB-710B was a nightmare.

As I see it, you've got a couple of options: you could connect a TV (any old TV/monitor) to one of your other video-out ports from your VCR so you can get a preview picture, or maybe even a camcorder.

Since you are delving into AVISynth , you could also try capturing with AmarecTV (or at least using it to view the picture) and setting up MPC to act as a histogram. Jagabo set me up for this in this topic:

https://forum.videohelp.com/threads/401225-Histogram-for-Amarec-TV

Unfortunately, I couldn't get MPC to run in concert with AmarecTV, but I suspect that that was an issue with my "well-used" PC.