Identifying stamp color

I have  my monitors set to Epson sRGA, since I use the Epson V600 scanner, When I first got on TSF, a member (who's name escapes me now...and he is no longer active on the forum) helped me set the color settings on VueScan. So to my eye on my monitors colors look 'true". I have noticed that images loaded onto TSF look 'subdued' for a lack of a better word. Comparing  the image of 782/782a on my monitor to the the posted imade (both on same monitor)  the 'pinkness' is much less apparent on the posted image. I'm guessing it may be caused by compression of some sort in the IMGBB /proboards link. (?)

I showed this in a screen shot a while back in another thread. With the broad assortment of monitors, scanners and software it's just something we live with... not to mention the individual color perception we each have

It seems, STAN, that you should buy a cheap PC just for Stamp usage 


R

see my recent PM LOL !!

stanley64
Vince, since I am a BNAPS member I kept this the Vol 79, # 4 issue and went back to this very fine Article on the CANADA 7¢ "bistre" Admiral and shades - when I re-read the color analysis section (p24) I did not feel in better shape to play with my screen (HP laptop)

But,.....quite interesting - Bravo to the members who are able to do these "tricks" to their computer(s)  .....and thanks for refreshing me to re-read this subject !!...and I do have 3 copies of this Unitrade # 113, one MNH-F, in album

René

When I returned to stamps after a long hiatus (20+ years), the Internet, digital resources, forums, and high-resolution scanners were all 'new" to my stamping experience. The calibrating efforts happened as a result of my early scanning efforts , bit for posts and my own use, and the fact that the scans were not looking like the actual stamps  which was very frustrating

and thus the trip down the rabbit hole began!

No Stan - I woud not know where to go.....into Perfom.....?? René

Thanks Stan - but no thanks - I have enough to do right now as you know !!!!

I'll see if I can load the linux version.  



thanks for lookingThe Mac version "installs" by dragging the app into applications... no Buxsoft folder  results. It took a few hours to scan in SG colors. Contemplating getting the Michel color guide. There doesn't seem to be many others in that type of format for stamps

Sooo... not to be a spoilsport here, but RGB is notoriously bad at helping computer users to identify "color". HSV (HSL) is FAR more useful. Scientists generally use CIE, which is kind of a more accurately weighted version (perceptually) of HSL - it's kind of a more subtle consideration of the difference between luminance and radiance. RGB is really only good for normalizing output.

Further, there really is no way to standardize stamp colors in RGB or any other code without addressing standardizations of things like ambient light levels and spectra, translucency (alpha channel?) of ink versus the color of the paper it's printed on, or even just weighting scanned channels properly against light source spectra.

Then there are the problems of aging, pollution, and other effects that gradually alter the chemistry of the inks and papers used to create stamps.

Honestly, the best answer to coming up with a mechanical method of accurate color identification for stamps is to train a whole bunch of quad-chromats in the processes expertizers go through, and have them work with really, really smart engineers and systems analysts and computer programmers to develop the mechanical processes. It's a frighteningly complex problem - color is NOT a property of objects (objects have spectral reflectance); it is a property of individual perception.

Just sayin'... vision science is pretty much what I do.

and a PS here... none of the above should suggest it's not worth all you're going through - I do it myself (scanner calibrations, ambient light normalization, yadda yadda yadda). I just know that my telling other people the HSV, RGB, or whatever codes I come up with to determine the color of Prussian blue using my equipment may not be the same as the results anyone else gets using their equipment, and may not even be the same as those determined by my own equipment for other stamps I know to be Prussian blue in my collection. Did that make sense?

So, short answer, there is no way objective way to mechanize the perception of color until we fully understand and can replicate all the underlying psychological inputs to those perceptions, and that will likely never happen. Remember that blue/black - white/gold dress thing from a years back? Color is a perception.

And, a final - hopefully helpful suggestion: use HSV or HSL for scanning (they're very common and accessible) and encoding, RGB for display, and CYM for printing. and they all have to calibrated separately for each individual piece of equipment you plan to use.

No problem Stan and I am always up for sharing notes either through the TSF boards, private message or even by email (the address can be found in my profile).

Regarding the existing colour profiles, I just left wha wast there and have been adding to it as the opportunity presents itself. If you think you need them, I can make a file.

Have fun and happy collecting!

The pictures are taken with the mobile phone in natural light conditions and at the same zoom magnification (I tried to achieve the same conditions)
The stamp on the right - before soaking in peroxide solution.
The first 3 pictures - the stamp after cleaning, on black, gray and white support.
The third stamp has the color closest to reality.
I'm curious if you scan a stamp on a black, gray or white background, such different color images will appear

Thanks stainlessb for the reply.
I don't have a scanner and I'm curious if it is possible to set the scanning area exactly the size of the stamp so that the light radiation of the support does not influence the result.
With the mobile phone camera it is difficult to achieve this and the white support in the images obtained has a bluish tint.

Thank you stainlessb, the scanner is on the list for Santa, but I wasn't very good...