How can you automatically correct White Balance in Video?

[vhelp]

You'll have find a tool that includes masking of some sort. I'm not familiar with the
correct terminology, but basically, its where you sketch a portion of a given area
and over-lay it on top of the same area to want to repeat it. You do with usually
in a timeline, for all the frames that change or whatever. But I'm pretty sure that
even this would take some time to do, depending on the complexity of the video
and how much masking and difference the areas to copy are.

I'm not saying that it can't be done. Actually, I think it can.

-vhelp 4323

[grannyGeek]

Well, I took a peek over the weekend. Meant to bring sample to post, but running late, I'm so sorry.

This isn't only a white balance thing, also the angle of the light changes, so the shadows and Brightness of the white house change.
Did you make a cut about halfway through the clip? There is a very abrupt change in the angle of the light, which makes the clip look like it jumps.
And I wasn't sure - is the "performer" kind of de-saturated? I thought he was wearing blue jeans, but if he's dressed in gray and black, disregard this question.
I also see some minor discoloration on the left-hand white wall, but I don't know if that was caused by mpeg compression.
It would be good if you could supply an original capture in Lossless (HuffYuv) or Uncompressed Avi.


If this is just a short version of your entire video, ColorYUV might work well for you. But read the documentation in the AviSynth help about the limitations of this internal filter.

ColorYUV(autowhite=true)

But I got better results with ColorMill.
For the "Light" bands, I dropped Levels a bit, and Saturation quite a lot (down to minus 15, I think). Then I bumped Gamma a tiny bit to increase Red and Yellow (which is negative Blue) to warm it up a little. I'll bring the exact settings tomorrow.
That way, the "warmth" of the white stayed pretty constant for the length of the clip, and the brick color looked richer, but the shadow changes still make the white go brighter/darker.

[grannyGeek]

PS -
Kind of in line with what vHelp says ---

There is an aviSynth filter called MaskTools, which might work for that kind of thing, but I haven't needed it badly enough to decipher the settings and the suggestions in the doom9 thread.


If you have to spend a month house-bound with two broken legs or something, you could also do a stationary overlay of a screenshot of the house, and then you could make bitmap masks (black opaque to block, white transparent to let the overlay show through). That would get tricky when the performer moves in front of the pillars, but would be do-able if you have a LOT of patience and a graphics app that lets you do what you need.

A long time ago, I did something similar to that with a 300-frame sequence, it took a lot of time, but it taught me how to use macros in my graphics program, so that was a good thing.

[Undead Sega]

well, i do have the oringal capture, and it was captured and edited with HuffYuv, brilliant piece of codec, and also tried Lagarith, but i found it very slow to edit with, even though it was made for it.

anyways, i will supply it, but beware, it is kinda big.

and yes, the performer (no names) is wearing grey, no jeans, and a black jacket.

and when filming, it was on the span of 20mins, it was due to the clouds in the sky, when they move, which gave us a slightly different direction of light as what can be seen on the pillars.

i was hoping once upload the oringal, is it okay if anyone can have a go at it to make it look better? i would really appreciate that.

give me abit, while i'll go home and upload the oringal.

would that be okay may i ask?

[grannyGeek]

Here's what I was able to accomplish for your DivX clip with a masked still overlay.
http://rapidshare.com/files/40700524/UptownXvid.zip.html

This solution would only work for scenes like your clip with a stationary background.
If the camera hadn't wobbled, the result would be better. There are some funky little jumps when the base of the pillars move, but the pillars stand still.
The change in light angle at frame 323 is still rather pronounced, but you could always blame that on a passing cloud.

Using the clip as its own mask means the original dark areas show through. I haven't figured out yet how to let only the performer show through without hand-painting frames in a graphics program.
Building the mask layer took some tweaking to kill highlights on performer's face, and his face still keeps wanting to be semi-transparent
Is the difficulty due to DivX compression and artifacts? I’ve only ever worked with DV and lossless avi. I'll check out your upload, whichever you decide to put up. Hope you don't go past 100 mb, my connection is fast, but file-host sites have slower mirrors.


The overlay clip is created by using FreezeFrame to force frame 149 to display for the entire length of the clip.

The mask layer is created entirely in the script, calling ColorMill to set Middle Point, Levels and Saturation.

Here's the script.
Change the path names to where your clip and your VirtualDub filters are stored, and give it a try. Be warned -- all those ColorMill calls make this script sloth-slow, and encodes at a blistering 3 fps !!! I just didn't have the patience to fiddle with colors and levels with Avisynth.

vPath = "C:\UPTOWN\"
vdPath = "C:\Program Files\Video\Edit\VirtualDub\plugins\"

###  load the VirtualDub filter
LoadVirtualdubPlugin(vdPath+"colormill.vdf", "colormill",1)

AviSource(vPath + "UPTOWNGIRLMVpillarsresized.avi")

# OPTIONAL  warm up the colors in source clip, 
#           delete Colormill line if you want original colors
# ColorMill must have RGB
convertToRGB32()
ColorMill(25702, 25954, 25186, 25190, 26465, 23143, 26468,
\ 26674, 24161, 25700, 25700, 25700, 25700, 1124, 5)

aBase = last

# force frame 149 to display for the entire clip
# this will be the top overlay layer
aOver =   aBase.freezeframe(0,380,149)

# use ColorMIll to create two black & white clip for mask layer
# different settings to clean pillar grooves in last part of clip

# almost grayscale
aMask = aBase
\.ColorMill(25700, 25700, 25700, 25700, 100, 104, 0, 25600,
\ 25700, 100, 22628, 51374, 25700, 1124, 5)

# strong contrast, black & white
bMask = aMask
\.Colormill(25700, 25700, 25700, 25700, 33380, 25800, 0, 25600,
\ 25700, 25700, 19300, 27904, 25700, 1124, 5)

# overlay the 2 mask clips to get cleaner pillars
# "Add" mode makes it brighter/whiter,  see Avisynth help about Overlay filter
cMask = overlay(bMask, aMask, mode="add", opacity = .25)

overlay(aBase, aOver, mask = cMask)

If you want to see how those scripted settings look in the ColorMill gui, copy the lines below into notepad, save as a .vcf file. In VDub/VDubMod open your clip, go to File > Load Processing Settings, open the vcf file. Repeat with other parameter strings from the script as desired. Remember to remove the \ line continuation character!

VirtualDub.video.filters.Add("Color Mill(2.1)");
VirtualDub.video.filters.instance[0].Config(25702, 25954, 25186, 25190, 26465, 23143, 26468, 26674, 24161, 25700, 25700, 25700, 25700, 1124, 5);

To add your own ColorMill settings to a script ---
In VDub or VDubMod, adjust ColorMill settings, go to File > Save Processing Settings. Open the saved vcf file in Notepad, copy the ColorMill "Config" settings into the avs script ColorMill call.
You can load and call many VDub filters this same way.

[edDV]

So how's this automatic white balance project going? Should I abandon the traditional manual technique?

[grannyGeek]

edDV, c'mon -- fess up. Tell us how you do it.

I haven't worked with autowhite at all, but generally do color corrections scene by scene with JDL_ApplyRange, or with Trim.

Maybe specific to this kind of clip with a LOT of white against a pretty dark background, I did get fairly decent results with ColorMill by dropping Levels and Saturation in the "Light" range. Is there an avisynth filter that lets you work in Light, Mid, and Dark ranges that way?

[Undead Sega]

hey everyone, i know its been awhile, and on the issue where i posted a clip on what kind of problem i was experiencing, i really do appreciate the help, but unfortuntely, it became too late to do the fixes and had to use what i had, but the end product tuned out to be fine.

if anyone is interested on what im talking about, here is what the clip was meant for:

http://www.youtube.com/watch?v=ksKlHtazVIc

again everyone, i really do appreciate it, and htis topic on hte original subject, White Balance, will carry on.

thanks, also, let me know what u think as well of the video.

Excellent.