Color Calibrating Experiment

[winsonli]

Hello. I'm currently thinking of building an online ink database. The ink reviews on FPN are very informative but there is one technical limitation with ink scans. Our monitors show colors differently.

 

To solve this problem, I'm experimenting with a method to calibrate colors of images. My idea is to let users calibrate colors (in a webpage, not the system/monitor color) to a standard item which everyone has. Bank notes should be the best item for this task. However, as I am in Hong Kong I can not easily get hold of foreign currencies so help would be appreciated.

 

I would like to ask for volunteers from different countries so I can get samples of different currency bank notes.

 

In the first part, volunteers would have to scan the corners of two bank notes of different nomination, send them to me, and then calibrate colors on a webpage which I would send you the link.

 

After that, I would post a link in this thread. Users can then try to calibrate colors and see if they closely match the actual object.

 

Please note that your system settings would not be affected in this experiment. I will just adjust the rgb values in the webpage (with javascript).

 

The experiment is successful if volunteers report that the colors on the monitor accurately matches that of the actual object. I would then attempt to develop a way to calibrate ink scans.

 

Please send me a PM if you would like to volunteer for the first part. Please indicate which currency you are using in the PM. Thank you very much.

Edited November 19, 2008 by winsonli

[tfwall]

A complicating factor might be fading of the currency. Perhaps there is an even easier method, like using a particular paper that is readily available via Amazon or something...

[thibaulthalpern]

[double post]

Edited November 19, 2008 by thibaulthalpern

[thibaulthalpern]

I'm sure professional who work with the print medium and colour monitors have a way to deal with this. It's called embedding a colour profile with the image scanned. I'm not totally knowledgeable about it but there are various standards. I don't think one needs to resort to getting foreign currency and calibrating with that.

[aymr]

What about the old photography trick of using calibrated black, white, and mid grey pieces on the scanner (not necessarily cheap, but available from photo stores), which would allow one to use Photoshop or GIMP to color-correct exactly?

[someonesdad]

In my opinion, the best way to do this is to use a calibrated spectroradiometer with carefully selected light sources, control the measurement geometry, and record the nonspecular reflection spectrum for each ink type. This is old hat to folks who study color science, but apparently no one has done this yet (someone suggested a "study" someone did on inks' location in color space, but it was a poorly documented study and it's not clear how they did the experiment).

 

I proposed an experiment for doing this a week or two ago, but there doesn't appear to be much interest. And, the more I thought about it, it's not terribly useful, as most folks aren't technical and will continue to rely on their own subjective opinions. I mentioned in that other topic that I'd be willing to do the work if some company would be willing to pay for the calibration of my spectroradiometer (about $600) and would pay me for my time (I'd charge half my normal consulting rate as I'm interested in seeing the results). But ink is small potatoes financially and I doubt any company would be willing to foot the bill.

[winsonli]

Thank you for the replies.

 

I had such idea because I was reading reviews of blue inks here and they are too vibrant on my monitor that they look no where close to how they actually are.

 

I wanted to be able to show calibrated ink scans inside the browser, not requiring the user to download it and tune it in Photoshop or something. Embedding color profiles may not work properly, because web browsers (as far as I know) would use its own default profile. Besides, with the same color profile, there are variations in color on different monitors.

 

The current idea, if works, is very convenient. Users only have to calibrate once, and then all ink scans they see on the webpage would be accurate. So when they order the ink, it would look exactly as how it looks on the monitor.

 

As for fading of bank notes, I do not have such problem with my local currency (Hong Kong dollars). The reason I thought of bank notes is that you don't have to buy it (I was going to say they are freely available but.. well..).

 

I am no expert in colors, so I might have got something wrong.

 

Even though, I would still love to have volunteers. Thanks.

[m00t]

But ink is small potatoes financially and I doubt any company would be willing to foot the bill.

 

 

Hence the reason why what this person is doing is relevant to the community - results will be easily calibrated on the user end, since it's the users who have so many different monitor types and color/gamma correction settings. Not to mention that it's cheap to implement - just the cost of some time. It would probably be a good idea to use a new dollar bill for most accurate color, as well as a new penny for balance on the red end of the spectrum... Not to mention that the new US $5 has Abe lookin' pretty in pink, or the $10 has yellow to calibrate to....

 

I was mulling over something like this before, too - I thought people could include a bill or a CMYK calibration print in their scans or photos of ink reviews, for the users to adjust their color settings to... alas, I am lacking in the scanning/picturetaking department, so I'll have to sit out on this one

[Paddler]

In my experience, it takes a really, really high-end monitor to calibrate properly. The only monitors that I have seen that will even calibrate black and white are CRTs. Plasmas and LCDs can't do it at all. I really don't want to go back to a CRT monitor so I can judge someone else's ink scans.

 

Paddler

 

[psfred]

I would suggest a standard photographic gray scale as the scanning standard. This will allow easy calibration of the scanner to white and black points and neutral gray, so that any calibrated monitor should then display the image correctly.

 

However, scanners are notorious for color error that have nothing to do with calibration (UV filtration, type of lamps or LEDs, color space of the scanner, etc). Photographs under controlled lighting are better, but some of the same caveats apply. It's not really going to be possible to get completely accurate scans or photographs no matter what you do -- although a standardization of the color space and scanner/camera images won't hurt a bit!

 

Peter

[Clydesdave]

Personally, I'm color blind and it's never been an issue with me.

 

 

 

[winsonli]

To better illustrate how my idea works, here is an example:

 

1. User A does calibration for once.

 

He takes out a bank note and compares it with the image in the webpage which I have prepared. He then adjusts the saturation and white balance of the image until an accurate match is obtained.

 

Say: -5 saturation. +10 white balance

 

2. User A contributes an ink scan.

 

He uploads the ink scan and adjusts the color on the webpage so that it matches that of the actual object.

 

Say: -1 saturation. +1 white balance

 

3. User B does calibration for once. (Like in step 1)

 

Say: -2 saturation. -2 white balance.

 

4. User B views ink scan.

 

As he has performed calibration before, the following adjustments would be made to the ink scan he sees on the webpage.

 

Saturation: [(-5)+(-1)]-(-2) = -4

White balance: [(+10)+(+1)]-(-2) = +13

 

This idea may have thought of things overly simple. Please correct me if so.

 

I'll carry out the experiment on two computers myself when I have access to a scanner this weekend. Meanwhile, I would love to gather more opinions.

Edited November 19, 2008 by winsonli

[Pink Ink]

Safari and Firefox 3 honor the ICC profiles images are tagged with. Wouldn't it just be easier if images were tagged and people used capable browsers?

 

I'm also for people adding a swatches of white and black and maybe grey to their images so that other people can color correct the images on their own.

[winsonli]

I understand that there is already a solution to this, but it requires a lot of time and expensive equipment.

 

Even though Safari and Firefox 3 honor ICC profiles, the color shown on the monitor is not accurate to what the actual object is unless the user calibrated his monitor with hardware calibrators. Hardware calibrators are not cheap.

 

A cheaper method of calibration is done with color charts. Still, the user has to get hold of one and has to change his computer settings. Not everyone are willing to change their system color settings.

 

My idea is simple. Users perform a first time calibration on the website so that all ink scans they see from the online database are accurate.

 

 

[excarnate]

I understand that there is already a solution to this, but it requires a lot of time and expensive equipment.

 

Even though Safari and Firefox 3 honor ICC profiles, the color shown on the monitor is not accurate to what the actual object is unless the user calibrated his monitor with hardware calibrators. Hardware calibrators are not cheap.

 

A cheaper method of calibration is done with color charts. Still, the user has to get hold of one and has to change his computer settings. Not everyone are willing to change their system color settings.

 

My idea is simple. Users perform a first time calibration on the website so that all ink scans they see from the online database are accurate.

I am not convinced your idea, as stated, will be very useful or will even work well enough to be worthwhile. However there is probably a way to make it work.

 

Anyone with a Macintosh has a built-in calibrator. Using that makes a lot of difference in the quality of what is seen on the screen. Photos of people, something probably quite common for most, benefit a great deal. I suspect there are similar (and free) programs for PC's and other computers. What would need to be done is:

1) Explain the problem to people. Showing someone a well calibrated monitor side-by-side with an uncalibrated one is the best way

2) Convince them it is worth their while to calibrate (photos of friends and family look SO much better it is amazing).

3) Show them where to go to get calibration done (On a Mac: System Preferences, Displays, Color tab, click the Calibrate... button, follow the instructions).

4) Get new color samples (NOT just swatches or q-tip swaps, but also line samples from various width pens) for all inks in the database that weren't calibrated to start with from a user who calibrated their camera and scanner and monitor (yes, the camera or scanner need to be calibrated, too).

 

I have some Kodak color squares, inexpensive, that I try to work into photographs I take where color matters (paintings, for example). This helps me make sure I have it right on my calibrated screen, at the very least, if/when I start doing reviews I'll be including them in at least some pictures. I'll have everything calibrated on my end, so at least there will be a good starting point.

 

Can anyone suggest a decent, hopefully free, calibration program for Windows PC's and for Linux systems? Most screens are so terribly off that even this basic form of calibration would be a great leap forward (to coin a phrase .

[winsonli]

I understand that there is already a solution to this, but it requires a lot of time and expensive equipment.

 

Even though Safari and Firefox 3 honor ICC profiles, the color shown on the monitor is not accurate to what the actual object is unless the user calibrated his monitor with hardware calibrators. Hardware calibrators are not cheap.

 

A cheaper method of calibration is done with color charts. Still, the user has to get hold of one and has to change his computer settings. Not everyone are willing to change their system color settings.

 

My idea is simple. Users perform a first time calibration on the website so that all ink scans they see from the online database are accurate.

I am not convinced your idea, as stated, will be very useful or will even work well enough to be worthwhile. However there is probably a way to make it work.

 

Anyone with a Macintosh has a built-in calibrator. Using that makes a lot of difference in the quality of what is seen on the screen. Photos of people, something probably quite common for most, benefit a great deal. I suspect there are similar (and free) programs for PC's and other computers. What would need to be done is:

1) Explain the problem to people. Showing someone a well calibrated monitor side-by-side with an uncalibrated one is the best way

2) Convince them it is worth their while to calibrate (photos of friends and family look SO much better it is amazing).

3) Show them where to go to get calibration done (On a Mac: System Preferences, Displays, Color tab, click the Calibrate... button, follow the instructions).

4) Get new color samples (NOT just swatches or q-tip swaps, but also line samples from various width pens) for all inks in the database that weren't calibrated to start with from a user who calibrated their camera and scanner and monitor (yes, the camera or scanner need to be calibrated, too).

 

I have some Kodak color squares, inexpensive, that I try to work into photographs I take where color matters (paintings, for example). This helps me make sure I have it right on my calibrated screen, at the very least, if/when I start doing reviews I'll be including them in at least some pictures. I'll have everything calibrated on my end, so at least there will be a good starting point.

 

Can anyone suggest a decent, hopefully free, calibration program for Windows PC's and for Linux systems? Most screens are so terribly off that even this basic form of calibration would be a great leap forward (to coin a phrase .

 

I tried to calibrate in expert mode and could not get it to work. I was stuck in step one, adjusting the right slider in the "native gamma" page. Just can't get the color to look right. I suspect it is the LED backlit screen? Does calibration work on your mac?

 

It would be a great idea for everyone to have their monitors calibrated. I was editing photos and photos which looks good on the monitor doesn't look nice when printed.

 

But there is one concern. Not everyone may like the colors of their system to be accurate. Take macs for an example. Their colors are very sharp and attractive, but I doubt they are accurate. Normal users like me may prefer warmer and saturated colors. So that's why I was thinking of calibrating the colors in the webpage only.

 

I agree with you for having lines of various nib sizes included on our database. Inks behave differently in differentn pens.

[excarnate]

Anyone with a Macintosh has a built-in calibrator....

I tried to calibrate in expert mode and could not get it to work. I was stuck in step one, adjusting the right slider in the "native gamma" page. Just can't get the color to look right. I suspect it is the LED backlit screen? Does calibration work on your mac?

 

It would be a great idea for everyone to have their monitors calibrated. I was editing photos and photos which looks good on the monitor doesn't look nice when printed.

 

But there is one concern. Not everyone may like the colors of their system to be accurate. Take macs for an example. Their colors are very sharp and attractive, but I doubt they are accurate. Normal users like me may prefer warmer and saturated colors. So that's why I was thinking of calibrating the colors in the webpage only.

Calibration does work. Don't fret if it isn't perfect on the first page, just squint like it says and get it as good as possible, then move on. There is a lot that has to be changed to make it right. After you're done try turning it on and off with a picture on the screen.

 

I doubt many would prefer non-calibrated colors after 1 day using a calibrated screen. Warmer can be gotten by calibrating to different white points (I use 6500°). Saturated is something you can do to the pictures you use but having accurate colors to start with helps a lot.

 

As far as printing, I haven't gotten that perfected. I intend to borrow the calibrator of a friend which also does scanner's and printers (mine is one of the cheap, $70 kinds).

 

BTW, I know this is a bit delayed. I've been busy (and if I looked at all the pages to catch up it'd be 51 of them!).

[037]

Hi there

Maybe the following would help in your experimentation.

 

https://www.fountainpennetwork.com/forum/in...showtopic=84174

Edited December 15, 2008 by 37