two colour wave files

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two colour wave files

Postby grahamhunt » Wed May 11, 2011 6:20 am

I have been messing about with my vidio suit colouring vidios orange and
blue green when played back over each other give interesting results
Has any one got any ideas for producing wave files no sound to play on
disc telivisor with two channels? :?:
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Postby gary » Wed May 11, 2011 10:28 am

Well, I have been looking into 2 colour NBTV for a while now. Unfortunately I haven't been able to find any information on how to convert from an RGB colour representation to what is described as, say, orange, or "blue green", as, of course, these aren't primary colours. There must be some kind of mixing rules but they are beyond me. What I mean is that there must be some relationship between orange and the primary colours red green and blue, something like o = r/2 + g/3 + b * 0, then presumably the "shades" of orange become proportional to the luminosity - oh I don't know - colour representation is not my strong point - if you know the answer to that then producing the wave file is trivial and I can certainly help you out there.
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Postby Alan » Wed May 11, 2011 8:33 pm

Gary
Here is my 2d worth about 2 colour systems, which I studied back in the '50's.
A lot of research was done by experimenters into the best colour filters to use, and the concensus of opinion came down to the 'Land' system. This was the name of a gentleman from the pre-war era who devised a system of colour photography using two colour filters, and two film plates, or a sequential system.
The clours were Red and Green. The closest to the actual colours were Signal Red, and Signal Green. The red was 'very red' and the green a Blue/Green, and the colour of the lens filters in the oil lamp illuminated railway signals.
Nowadays, the frequency would be given, so those with the equipment needed should pay a visit ot a Preserved Railway to measure the filters.
In presentation, Land used a sequencial method of showing the the movie films that he had made, and I saw a short travel film of his on local T/V last year. Brilliant!
Looking forward to your future developments.

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two colour wave files

Postby grahamhunt » Thu May 12, 2011 6:13 am

All I have been able to find is the mixing ratios for displaying files
Left channel orange 67% Red 33% Green
Right channel Blue Green 67%blue 33%green
all though to some extent adjustments can be made with the rgb leds
Does this help gary
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Postby gary » Thu May 12, 2011 11:42 pm

Well having tried that with a small selection of videos it seems to work fairly well, see attached video (AVI)

Here is a version of Video2NBTV with a renderer to produce 2 colour NBTV (other wise to club standard) - just unzip it into a folder of choice and use it as per the normal version.

Here is an example wave file.


and here is the original video:
http://video.google.com/videoplay?docid ... 905163265#
(I can't post flvs for some reason)

Let me know if you try it on a mechanical monitor please.

PS:

If any one can tell me why sometimes I can add attachments within the body of my text, and then at other times they get added after my signature (thus losing all synchronism with the text) I would be eternally grateful.

Cheers.

Edit:
Whoops, I forgot to add the little viewer so you can see what your conversions look like (adding this to TBP is a major undertaking so that can wait until we have sorted out this format). Also I renamed the plug-in as I got Graham confused with Phil - sorry Graham. These are now in the attached zip file.

Edit 2:
The attached zip file had an incorrect version of video2NBTV in it, so I have removed it.
Please download Video2NBTV version 3 from my web site: http://users.tpg.com.au/users/gmillard/ ... all-V3.exe
and the viewer from here: http://users.tpg.com.au/gmillard/nbtv/GHGM2CViewer.exe
Attachments
2 colour test.avi
(13.52 MiB) Downloaded 744 times
slow_motion_close_up_British_Union_Jack_flag_waving_in_windo.wav
(1.8 MiB) Downloaded 678 times
Last edited by gary on Fri Feb 17, 2017 11:56 am, edited 3 times in total.
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two colour wave files

Postby grahamhunt » Fri May 13, 2011 7:13 am

Cheers Gary as soon as I can make a pilgrimedge to maplins for some
R G B leds and find the time to build another D Aldridges led driver I will
report on results
Many thanks Graham :D
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Thanks Gary

Postby holtzman » Fri May 13, 2011 7:39 pm

I'm very impressed how quickly you managed to produce a new version of your software and by results it gives. Probably I'll try this on my monitor. The advantages are that no decoder is needed, just two video amps. Another advantage is that RGB is something obvious for our days, while this two-color system is kind of dead tech (like mechanical tv in general :wink: ) and thus its historic value is greater.

I wonder what is better for reproduction: the use of RGB leds with different resistors for R, G and B or two types of leds - orange and blue? I have seen orange leds, but never have seen blue leds of that special greenish color.
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Re: Thanks Gary

Postby gary » Fri May 13, 2011 8:21 pm

holtzman wrote:I'm very impressed how quickly you managed to produce a new version of your software and by results it gives. .


Thanks, with the new plug-in system it is relatively easy to add new formats, however this format was slightly more complicated because all other formats assume audio on the right channel, because of this I had to make a small change to the main application, otherwise the 2 colour plug-in would have worked with the current release. I am not really happy that the main app needs to know something specific about this format but at this stage I don't see how it is to be avoided, I may be able to make a small change to the plug-in specification we'll see.

holtzman wrote:I wonder what is better for reproduction: the use of RGB leds with different resistors for R, G and B or two types of leds - orange and blue? I have seen orange leds, but never have seen blue leds of that special greenish color.


That's a very good question, and I think some experimentation will be required, but since I can reproduce the original material reasonably well on an LCD monitor by reverse proportioning the orange and bluegreen components as per Graham's specification back to RGB, then presumably that should work at least as well when using separate red green and blue leds or a single RGB led with the currents through each colour apportioned in the same manner. The method of doing that is left to the student as an exercise ;-).

Keep in mind also that I have only tested this on a small sample of videos, it seems to work well with bright primary colours and videos of two colour movies...
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Postby gary » Fri May 13, 2011 8:52 pm

Please see my edit two posts back for 2 colour viewer I forgot to add.
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2 colour wave files

Postby grahamhunt » Mon May 16, 2011 6:17 am

As usual maplins have discontinued R G B leds I decided to try coloured
filters instead one orange plastic bag one blue plastic bag and two very missmatched led sources one with 3 watt luxon one with ordinary king
bright turn blue right down orange right up colours not that bad considering At least gives me encouragement :lol:
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Postby gary » Mon May 16, 2011 10:07 am

Using filters is not a bad idea if you could source the right colours, but couldn't you just use three separate red green and blue leds and mix them through an appropriate diffuser? That was the approach I was going to take (once I've completed my FSS camera).
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Postby holtzman » Mon May 16, 2011 7:38 pm

Gary, I tried to convert some videos and the result is extremely low in contrast on your small player. When I tried to increase volume bu means of Audacity, and also by another sound editor, the player did not play back these modified wav files and stalled (did not response). Even without volume change, it stalls on each file which was "saved as" in any sound editor.
Normally, I use to increase volume in conventional NBTV files since I don't see the reason why they are so low in volume and my one fet amp has not enough gain to play "raw" video2nbtv files with good contrast.
Thanks for your programmes anyway!
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Postby gary » Mon May 16, 2011 7:46 pm

Yes I can't guarantee the player will work with modified files - it is just a quick and nasty lash up to enable me to check the output of Video2NBTV. There shouldn't be a contrast problem when just playing the output of video2NBTV as they are "matched" digitally (i.e. "what you see is what you got"). If there is a perceived contrast problem it must be due to the colour conversion, can you post the original and converted files please?
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two colour wave files

Postby grahamhunt » Tue May 17, 2011 7:03 am

I am not giving up on leds just do not have any coloured ones in stock
and am ordering them online when I have worked out what else I need
meanwhile playing with filters
Graham :oops:
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contrast

Postby holtzman » Tue May 17, 2011 7:42 am

Gary, the files I converted have the same low contrast as those converted by you. Please see fragment of your wav file with flag - it uses only about 35% of maximum signal level. My question is why not to set the converter such that white image areas would be represented by something like 90%? There still remains 10% margin before clipping.
BTW, Baird used different color couple in his color experiments - Alan wrote about it. It's 100% red channel and 50% green+50% blue channel. I tried to experiment with it in Photoshop and got some interesting results.
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flag file.jpg
flag file.jpg (66.16 KiB) Viewed 11012 times
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