Removing hue but preserving saturation?

[Mephesto]

how shall I create a luma mask? I want everything 40 pixels darker from absolute white and up to be left alone.

Something like:

Thanks, this worked. I ended up only brightening by 15 instead of 40 because the banding artifacts were too much, like I thought.

A waveform monitor of the luma channel is basically a graph of the brightness of each pixel. Consider one horizontal line of pixels. Some are brighter, some are darker. Instead of showing the brightness of each pixel as brightness, transform that line of pixels to a graph where the y axis represents the brightness of the pixel (0 at the bottom, 255 at the top), the x axis the position of the pixel across the line.

Wait, so one pixel on the waveform represents an entire horizontal line or one horizontal pixel? I can't imagine the latter because the waveform is only a fraction of the 960 pixels the picture is. And what does the intensity of the waveform represent if the x,y is the brightness? I see bright and dark purple in the right waveform.

Now draw the same graph for every scan line of the image, all drawn on top of each other. In the final graph bright areas indicate many pixels had that brightness in that column. Darker areas indicate fewer pixels had that brightness. Black areas indicate no pixels had that brightness.

Ok so one waveform pixel = one entire line from pic. x,y position is the average brightness. I still don't get why the waveform has a varying brightness then.

[jagabo]

Some pseudo code will probably make it clearer to you:

uchar image[height][width]; # a luma only image
ulong graph[256][width];    # the graph we're building

for (y=0; y<height; y++) # for each scan line
{
         for (x=0; x<wdith; x++) # for each pixel of the scanline
         {
                 uchar brightness = image[y][x];  # brightness of the pixel
                 graph[brightness][x]++; # brightness transformed to height in the graph
         }
}

[Mephesto]

Nope, that's complete Greek to me.

Btw, there's a part filmed in almost pitch black.
http://www.sendspace.com/file/fxfjt5
The quality is so bad that I can't tell if that's the guy or girl, but this is my best restoration attempt.
http://www.sendspace.com/file/jsnmex

What do you all think?

[jagabo]

Nope, that's complete Greek to me.

Sorry, I thought you some programming.

Did you understand anything I said in post 59? Did you look at the post it linked to? It's actually pretty trivial once you "get it".

Did you understand the part about transforming the brightness of each pixel to a height in the graph?

[poisondeathray]

Nope, that's complete Greek to me.

Btw, there's a part filmed in almost pitch black.
http://www.sendspace.com/file/fxfjt5
The quality is so bad that I can't tell if that's the guy or girl, but this is my best restoration attempt.
http://www.sendspace.com/file/jsnmex

What do you all think?

Hahaha it's a guy! or a manly woman ... Short hair, guy shorts, triceps shape and "relative" musculature . So you can close the thread now

It's a good clean up, but looks like heavy neat video treatment

[Mephesto]

Nope, that's complete Greek to me.

Sorry, I thought you some programming.

First part that loses me is the ++, what is that?

Did you understand anything I said in post 59? Did you look at the post it linked to? It's actually pretty trivial once you "get it".

Each pixel converted to direction, that's fine. But in my blue grass photo it showed a big bright line on the bottom of the green waveform, does that area correspond to the dark grass? So the brightness means there are lots of pixels of this darkness in this vertical line?

I think I get it. Don't see much use for this though. It's confusing and hardly more resourceful than a simple histogram.

Hahaha it's a guy! or a manly woman ... Short hair, guy shorts, triceps shape and "relative" musculature . So you can close the thread now

I thought the person had long hair but it appears to be a shadow from his head that was the same brightness as his hair due to the low light.

I didn't think it would make sense for the GIRL to film her partner sleeping, but then again I've noticed women including mine like to observe their sleeping partner. I never understood why. They really are weird sometimes.

It's a good clean up, but looks like heavy neat video treatment

It had HEAVY noise, most of it not even moving, after turning up the brightness and contrast. You should see how ugly it looked. NV couldn't even do the job but I have this tweak where I can increase the radius to 20.

[poisondeathray]

Hahaha it's a guy! or a manly woman ... Short hair, guy shorts, triceps shape and "relative" musculature . So you can close the thread now

I thought the person had long hair but it appears to be a shadow from his head that was the same brightness as his hair due to the low light.

I didn't think it would make sense for the GIRL to film her partner sleeping, but then again I've noticed women including mine like to observe their sleeping partner. I never understood why. They really are weird sometimes.

Well you have the whole clip, maybe there are more clues. You can be CSI Mephisto

By why do you assume it's a GIRL filming HER partner ? Maybe it's a BOY filming HIS partner

[Mephesto]

Well you have the whole clip, maybe there are more clues.

That clip is the entire scene. The first hour looks like the first screenshot I posted, timestamp puts it at 10 PM to 11 PM then it cuts off to 2:30 AM where the guy fell asleep and the girl decided to film him without turning on the night vision on the cam for a few seconds, then the clip ends.

By why do you assume it's a GIRL filming HER partner ? Maybe it's a BOY filming HIS partner

There was nobody in the clip except them for a whole hour and you do see her face up close a few times.

You can be CSI Mephisto

Hah, I wonder if anyone finds it weird I'd spend so much time restoring and cleaning up a clip that I'm about to delete after it's encoded. This is how I am off my Prozac, but I tend to be homicidal when on it and don't wanna blow up the 9/11 towers again so...

[jagabo]

in my blue grass photo it showed a big bright line on the bottom of the green waveform, does that area correspond to the dark grass? So the brightness means there are lots of pixels of this darkness in this vertical line?

That is a vector scope plot of U and V. Ie. each pixel has a U and V value, it is plotted on that graph as U horizontally, V vertically. The center of the graph represents low saturation (grey), the edges high saturation of the different hues. A strong line from the center toward an edge indicates all pixels had the same hue. Watch RotatingHue.MKV in post #60.

[Mephesto]

in my blue grass photo it showed a big bright line on the bottom of the green waveform, does that area correspond to the dark grass? So the brightness means there are lots of pixels of this darkness in this vertical line?

That is a vector scope plot of U and V. Ie. each pixel has a U and V value, it is plotted on that graph as U horizontally, V vertically. The center of the graph represents low saturation (grey), the edges high saturation of the different hues. A strong line from the center toward an edge indicates all pixels had the same hue. Watch RotatingHue.MKV in post #60.

Okay I played around with that Animate() function for brightness, contrast and all kinds of settings while watching videoscope. I get how it is now. It would be more convenient if there was a Vdub filter as good as videoscope so I wouldn't have to keep re-opening AVS scripts in Vdub.

While this thread is still open, I gotta ask if anyone has experience in color restoration? If hue AND saturation is lost in greyscale, how do they make those colorized films look so natural? Adding hue to a region is easy, but saturation is so diverse that it never looks right to pick a fixed value. Anyone know what they do?

[manono]

It would be more convenient if there was a Vdub filter as good as videoscope so I wouldn't have to keep re-opening AVS scripts in Vdub.

After making a change to the script and saving it, just hit F2 on your keyboard to open at the last place you were at, with the change in effect. Or have I misunderstood?

[Mephesto]

It would be more convenient if there was a Vdub filter as good as videoscope so I wouldn't have to keep re-opening AVS scripts in Vdub.

After making a change to the script and saving it, just hit F2 on your keyboard to open at the last place you were at, with the change in effect. Or have I misunderstood?

I didn't even know about that. This will make things a lot easier but it's still annoying having to edit the script, erase numbers, retype new ones, save script and press F2 when Vdub has filters with sliders and preview windows where I have more direct, convenient control. The animate feature in avisynth eases that up a bit though, but then you have to figure out in which order the settings of a filter come.

[manono]

...but it's still annoying having to edit the script, erase numbers, retype new ones, save script and press F2 when Vdub has filters with sliders and preview windows where I have more direct, convenient control.

AvsPMod has sliders and is maybe the closest to a GUI that AviSynth has. I've never bothered to learn it, though.