PDA

View Full Version : Colorization of B&W photos


dbcisco
05-20-2009, 06:07 PM
The state of the art method of colorization has a serious flaw, human input. A person must select the base colors to be used for each section. This is very subjective and prone to error. In short, a silver plane with blue stripes can come out blue with red stripes. Basing "authenticity" of color schemes based on colorized B&W photos is extremely flawed.


"Our method is based on a simple premise: neighboring pixels in space-time that have similar intensities should have similar colors. We formalize this premise using a quadratic cost function and obtain an optimization problem that can be solved efficiently using standard techniques. In our approach an artist only needs to annotate the image with a few color scribbles, and the indicated colors are automatically propagated in both space and time to produce a fully colorized image or sequence. We demonstrate that high quality colorizations of stills and movie clips may be obtained from a relatively modest amount of user input." (Colorization Using Optimization, Anat Levin (http://www.cs.huji.ac.il/%7Ealevin/), Dani Lischinski (http://www.cs.huji.ac.il/%7Edanix/), Yair Weiss (http://www.cs.huji.ac.il/%7Eyweiss/))

7car7
05-26-2009, 10:23 PM
Just curious, what prompted you to make this thread? Is there a current case of colored pics happening?

My grandma used to do this - but mostly just family shots - she'd do them pretty much right after development, so she actually knew what color sweater it was.:tc:

dbcisco
05-27-2009, 12:14 AM
Started this thread because it was off topic where it was brought up. There seemed to be a lot authors and other experts who are basing WWI aircraft color patterns on these faked photos. Just trying to get the truth out.

phupper
05-27-2009, 07:58 AM
Where could we find some of your examples of WWI planes with the proper coloring?

Phil

dbcisco
05-27-2009, 12:38 PM
Where could we find some of your examples of WWI planes with the proper coloring?

Phil

There are only a few genuine color photos from WWI and the color is not trustworthy due to fading and aging. Another source is paintings and color prints from the period, but again these are biased representations and most either after the fact or flights of fancy (pun intended). The best source is unrestored museum pieces that have undergone scientific analysis to determine original color and authenticity, very rare (lozenge pattern probably the best studied). Most surviving WWI planes were converted for private use or destroyed.

The point is this, anyone who claims that they know what the color patterns of WWI aircraft are is probably wrong. Next time someone tells you your color pattern is wrong, ask them to prove it! All they can prove with B&W photos is that greyscale doesn't match (IE: pink vs magenta).
I am all for historical accuracy but this is one of those grey areas (pun intended again).

degreen60
05-27-2009, 02:51 PM
I had a 1933 MG I wanted repainted. After doing research on old paint I found out the paints were so unstable that even if you have a paint chip it is probably not the shade of the original paint. Paint from the same batch could either lighten or darken over the years. I paint my WW1 planes to be colorfull. I do not try to make the paint all the same shade either. If it is streaked it is brobably more correct than a smooth finish. Course I do not build real scale models either, just like good looking planes in the air.

dbcisco
05-27-2009, 03:04 PM
As a historian and anthropologist, I can tell you that even the best museums in the world are mostly full of educated guesswork. I get upset sometimes with scale purists who think they are "experts". A good scientist (real expert) knows that he is very like going to be wrong about a great many things.

7car7
05-27-2009, 03:57 PM
This may be off topic, (maybe not).

I was trying to figure out the colors for the roundels for my current SE5a build. It's done in South Africa colors.

I learned from a gentleman on http://www.theaerodrome.com/
that blue in particular was a very bad color for being reproduced with the old style film that was around then. A blue outer ring on a British plane would look almost white, or VERY ligtht color, even though we're pretty sure we know the outer ring in blue was a darker shade.

So, the moral of the story is, the old photos just aren't to be trusted. Can only go by samples - if even those.

dbcisco
05-27-2009, 04:22 PM
For brightness and contrast the B&W photos can help but not in choice of color. sky blue versus navy blue for example, yet from the B&W photo it mgiht as well be pink vs crimson.

The easiest way to check (and the only honest one) is to compare a B&W photo of your model to a B&W photo of the original. I have a close to period box camera, but I can't get film for it anymore :(

phupper
05-27-2009, 06:33 PM
If I understand correctly, I still have to know what colors a WWI plane is. Once I know that, then your system will color the photo for me?

"anyone who claims that they know what the color patterns of WWI aircraft are is probably wrong"

Have you actually used your system on any WWI plane photos, or are you still one of the "probably wrong"? Is this something your system can do, but just has not done yet?

Phil

dbcisco
05-27-2009, 06:54 PM
It isn't my program. It is the cutting edge technology and property of Anat Levin (http://www.cs.huji.ac.il/%7Ealevin/), Dani Lischinski (http://www.cs.huji.ac.il/%7Edanix/) and Yair Weiss (http://www.cs.huji.ac.il/%7Eyweiss/).
You need to know what the color in an area of the photo is (if that is possible) and it will basically auto-fill the area with shades of that color based on greyscale in the B&W original. There is no method that can turn B&W into color by itself (IE: pink and skyblue are identical in gray). Again, the point is that there are people in the hobby that are very "snobbish" and also very wrong. I love to put people like that in their place. I used to be a snobby amateur, now I realize how wrong, misleading and annoying to professional historians and anthroplogists I had been. Now I just annoy the snobs.

dbcisco
05-28-2009, 04:06 PM
This is a genuine color photo (Lumiere process) of a Nieuport.

http://upload.wikimedia.org/wikipedia/commons/8/81/Nieuport_17_C.1.jpg

Is it silver, grey, khaki, light tan or off white?

Is it a good photograph with the correct colors?

Should I assume that all B&W photos of "pale" Nieuports are this color?

Is this a new plane? Does the dope fade with age, tenperature, wear?

Did the picture/plane look this way when taken?

..and the last scientific statement, "Prove it."

And that is just real color photos. Now, about those colorized B&W photos.....:{

floss
10-26-2009, 08:44 AM
Heres a couple of Turkish Albatros's in kodachrome ;)

FS Gilbert
11-02-2009, 07:34 PM
Getting the "right" color is kind of like, how paper clips do you have to steal from your boss before it is a felony? The fact is that paint at that time varied from batch to batch even from the manufacturer and that was where the term, "Boxing the paint", came from. Even house painters did it. You would mix all the gallons of paint that you were going to use together before starting, to have a uniform color throughout.

But I certainly know of the authorities, whether it be in aviation or boating or especially camera equipment! For the most part, they are really more interested in the discussion than in the action of building or flying or sailing or taking photos. We see them everywhere and for me, they provide the necessary comic relief and entertainment that we need more of in these troubled times. It is like the person who cuts you off in traffic. Don't get angry, get him/her angry. Wave and smile. It really pisses them off!