Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: saiguy on February 02, 2018, 02:27:13 pm
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Seeking advise. Not certain which color space to use as there seem to be competing benefits.
I'm doing a scan project of about 9k slides, mostly Kodachrome. I have raw scanned 4k of them to SF8 HDR thus far and will now post process those and will be delivering them via a Lightroom Catalogue when project is finished. The project will be housed on PC and likely not be color managed.
If I use ARGB they could get better prints IF they get a decent photo printer, and want to print. But may not show well on screen or via a projector.
sRGB would limit printing at home, but that may not be employed anyways. It would be safer for an uncalibrated screen/projector though.
Thanks for any input on this. Could be dammed if you do and dammed if you don't.
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Seeking advise. Not certain which color space to use as there seem to be competing benefits.
I'm doing a scan project of about 9k slides, mostly Kodachrome. I have raw scanned 4k of them to SF8 HDR thus far and will now post process those and will be delivering them via a Lightroom Catalogue when project is finished. The project will be housed on PC and likely not be color managed.
If I use ARGB they could get better prints IF they get a decent photo printer, and want to print. But may not show well on screen or via a projector.
sRGB would limit printing at home, but that may not be employed anyways. It would be safer for an uncalibrated screen/projector though.
Thanks for any input on this. Could be damned if you do and damned if you don't.
Why don't you do the conversion into 16-bit Pro Photo and store those files? Then export as sRGB and/or Adobe RGB. That way if your client's needs change, you won't have to rescan.
Jim
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You don't mention the subject matter, but Jim's advice to keep your options open is good.
I have seen a photographer's entire collection of flower photographs scanned in srgb. That colour space rendered enough of the colours out of gamut to make the results particularly nasty.
David
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Thanks Jim and David,
Subject matter is travel photos mostly shot in India starting from 1977. Mostly houses, temples, schools; places associated with the 120 year old monastic order he belongs to.
I am working in ARGB. I have read this doesn't always play well on uncalibrated screens, and non color managed web browsers. Out put size is 5x7 inch. Thus my question.
If they want some special prints I would be re-scanning at larger size and most likely in ProPhoto. I can get decent letter size prints from the ARGB files I will keep even if the project is delivered in sRGB.
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Everything you thought you wanted to know about color gamut
A pretty exhaustive 37 minute video examining the color gamut of RGB working spaces, images and output color spaces. All plotted in 2D and 3D to illustrate color gamut.
High resolution: http://digitaldog.net/files/ColorGamut.mov
Low Res (YouTube): http://www.youtube.com/watch?v=n0bxSD-Xx-Q
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Andrew, I watched your excellent video for a 3rd time just now. I get it and I follow your advise in my personal work.
Question is how to deliver a project to non color managed end user. ARGB or sRGB?
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Question is how to deliver a project to non color managed end user. ARGB or sRGB?
Not color managed = sRGB delivery. I would also Keep/deliver the original scans in ProPhoto 'for professional use only'.
Jack
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Thanks Jack.
That's what I thought. Since this is a large collection that they consider important I should be able to get them to calibrate their new PC lap top screen that will house the project. Otherwise I'll deliver in sRGB.
I have processed 120 of them in ARGB but will use ProPhoto from now. Is it safe to deliver ProPhoto images if they profile their monitor? Project will be managed in Lightroom.
Converting the ARGB's to ProPhoto; I assume nothing can be gained by that. Is this correct?
thanks again,
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Question is how to deliver a project to non color managed end user. ARGB or sRGB?
You can't and shouldn't. sRGB doesn't guarantee anything without color management! Next up:
sRGB urban legend & myths Part 2[/font]
In this 17 minute video, I'll discuss some more sRGB misinformation and cover:
When to use sRGB and what to expect on the web and mobile devices
How sRGB doesn't insure a visual match without color management, how to check
The downsides of an all sRGB workflow
sRGB's color gamut vs. "professional" output devices
The future of sRGB and wide gamut display technology
Photo print labs that demand sRGB for output
High resolution: http://digitaldog.net/files/sRGBMythsPart2.mp4 (http://digitaldog.net/files/sRGBMythsPart2.mp4)[/font]
Low resolution on YouTube: https://www.youtube.com/watch?v=WyvVUL1gWVs (https://www.youtube.com/watch?v=WyvVUL1gWVs)[/font]
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Not color managed = sRGB delivery.
And if the viewer has a wide gamut display, bad news. Anyone who cares a lick about color appearance has to use color management. Those who don't care don't know and don't use it,
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Thanks Andrew,
I watched your Urban Legends video before but couldn't remember where I saw it. Nice to see it again.
Would you recommend ProPhoto output and tell my friend he needs to profile the viewing devices?
Much appreciate all the expertise you bring to us.
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Depending on what others do with the actual document maybe ProPhoto RGB but always with color managed applications! And a profiled display.
Thanks Andrew,
I watched your Urban Legends video before but couldn't remember where I saw it. Nice to see it again.
Would you recommend ProPhoto output and tell my friend he needs to profile the viewing devices?
Much appreciate all the expertise you bring to us.
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Andrew,
Just watched Urban Legends One. You answered my last question in that video. Now I get it. Thanks again.
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Everything you thought you wanted to know about color gamut
A pretty exhaustive 37 minute video examining the color gamut of RGB working spaces, images and output color spaces. All plotted in 2D and 3D to illustrate color gamut.
High resolution: http://digitaldog.net/files/ColorGamut.mov
Low Res (YouTube): http://www.youtube.com/watch?v=n0bxSD-Xx-Q
By far the most well done explanation I have seen of all of this!
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......and tell my friend he needs to profile the viewing devices
I assume he doesn't have a puck and profiling software, but that you can profile monitors. Why not profile his for him as a part of your project? At least that way, he will start out seeing them properly.
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BradSmith,
My friend lives 5.5 hour drive from my place. I think they plan to buy a new PC lap top for the project. I'll have them get perhaps i1Dicplay Pro. They may get a projector also. I will show them how to run the profiling process.
Thanks for your good suggestion.
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BradSmith,
My friend lives 5.5 hour drive from my place. I think they plan to buy a new PC lap top for the project. I'll have them get perhaps i1Dicplay Pro. They may get a projector also. I will show them how to run the profiling process.
Thanks for your good suggestion.
You should have your friend carefully review laptops for minimal change with tilt/viewing angle. Most are pretty bad at that and most have crummy gamuts lower than sRGB just to get the brightness up w/o killing battery life. Understandable compromise but a PITA for color managed apps.
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And if the viewer has a wide gamut display, bad news. Anyone who cares a lick about color appearance has to use color management. Those who don't care don't know and don't use it,
If some viewers have a wide gamut display and they are color managed, no problems. On the other hand if they are not color managed then bad news no matter the choice. So if one does not know who is going to be watching how, imho all one can do is go for the highest population/probability and that is sRGB. And deliver also a wider gamut version like ProPhoto for the professionals in the room that know what to do with it.
If on the other hand one has control of the display chain, then I would substitute sRGB with the smallest color space that encompasses the output medium's and make sure color management is properly set up. In most cases that is either Adobe RGB or sRGB depending on monitor. I would do this last conversion myself because I do not trust unknown software to perform it properly on the fly.
Jack
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If on the other hand one has control of the display chain, then I would substitute sRGB with the smallest color space that encompasses the output medium's and make sure color management is properly set up. In most cases that is either Adobe RGB or sRGB depending on monitor. I would do this last conversion myself because I do not trust unknown software to perform it properly on the fly.
Jack
Was thinking to export as catalogue with masters from LR to their new quality external drive, then import that to their lap top via copy files. I assume LR will do that properly.
Hard to know how many files will have color outside ARGB.
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Was thinking to export as catalogue with masters from LR to their new quality external drive, then import that to their lap top via copy files. I assume LR will do that properly.
Hard to know how many files will have color outside ARGB.
This is fairly easy to do with Matlab and their image toolbox. One can automate reading a long list of images, converting to sRGB then generating statistics on the dE76 (or dE00 which is a bit better). It processes over a million pixels/sec.
It shouldn't be hard to write such a program in C++. I have C++ source for a function that will crank through image comparisons producing dE00 results at the rate of 140,000,000/sec on my 7 y/o desktop. Writing the code for converting Adobe RGB or ProPhotoRGB to sRGB should be similarly as fast or faster and really shouldn't even need to use a library like Little CMS as it's quite simple.
Then it would be easy to identify those images that are most problematic and look at them specifically.
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If some viewers have a wide gamut display and they are color managed, no problems.
Or sRGB like displays. The point is, none of it matters IF one doesn’t profile the display and use an application that understands what the scale of the numbers mean along with the display profile. Otherwise, all bets are off and that is true for any RGB color space and any gamut display.
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Or sRGB like displays. The point is, none of it matters IF one doesn’t profile the display and use an application that understands what the scale of the numbers mean along with the display profile. Otherwise, all bets are off and that is true for any RGB color space and any gamut display.
Yes, the last bit is indeed the context of this thread and my point :)
Question is how to deliver a project to non color managed end user. ARGB or sRGB?
Non color managed end user = sRGB. It offers the least likely chance of missing the target altogether.
Jack
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Non color managed end user = sRGB.
Nope it's non color managed and the color appearance is totally out of that users control in such a situation and there is no guarantee of any kind of visual match to sRGB. Without Color Management, sRGB is a meaningless concept.
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Seeking advise. Not certain which color space to use as there seem to be competing benefits.
I'm doing a scan project of about 9k slides, mostly Kodachrome. I have raw scanned 4k of them to SF8 HDR thus far and will now post process those and will be delivering them via a Lightroom Catalogue when project is finished. The project will be housed on PC and likely not be color managed.
If I use ARGB they could get better prints IF they get a decent photo printer, and want to print. But may not show well on screen or via a projector.
sRGB would limit printing at home, but that may not be employed anyways. It would be safer for an uncalibrated screen/projector though.
Thanks for any input on this. Could be dammed if you do and dammed if you don't.
Being curious, and already having half the code, I completed a program to scan tif files in either Adobe RGB or ProPhoto RGB, and print a summary of what fraction of the colors, clipped to sRGB, exceed various levels measured in Delta E 2000. Here's a summary of the Roman 16 image set provided in I1Profiler and the Kodak, PDI image from DryCreek. For the latter, a second image has their added synthetic colors removed.
All the images, except the 3 black and white ones, show some fraction of dE00 clipping. Most of the Roman images are designed to stress printing and it's pretty easy to see the color shifts soft proofing them against sRGB. The widely available PDI image has little visible change outside of the synthetics DryCreek added and the Colorchecker Cyan patch.
Image File: roman16_01_highkey.tif
Fraction of dE00 Between 0 and 1: 0.999979
Fraction of dE00 Between 1 and 2: 0.000019
Fraction of dE00 Between 2 and 3: 0.000000
Fraction of dE00 Between 3 and 4: 0.000002
Image File: roman16_02_midtone.tif
Fraction of dE00 Between 0 and 1: 0.999775
Fraction of dE00 Between 1 and 2: 0.000153
Fraction of dE00 Between 2 and 3: 0.000034
Fraction of dE00 Between 3 and 4: 0.000015
Fraction of dE00 Between 4 and 5: 0.000013
Fraction of dE00 Between 5 and 6: 0.000010
Image File: roman16_03_lowkey.tif
Fraction of dE00 Between 0 and 1: 0.999651
Fraction of dE00 Between 1 and 2: 0.000141
Fraction of dE00 Between 2 and 3: 0.000084
Fraction of dE00 Between 3 and 4: 0.000061
Fraction of dE00 Between 4 and 5: 0.000034
Fraction of dE00 Between 5 and 6: 0.000027
Fraction of dE00 Between 6 and 7: 0.000002
Image File: roman16_04_cyan.tif
Fraction of dE00 Between 0 and 1: 0.583319
Fraction of dE00 Between 1 and 2: 0.027711
Fraction of dE00 Between 2 and 3: 0.024007
Fraction of dE00 Between 3 and 4: 0.043395
Fraction of dE00 Between 4 and 5: 0.061867
Fraction of dE00 Between 5 and 6: 0.209625
Fraction of dE00 Between 6 and 7: 0.045450
Fraction of dE00 Between 7 and 8: 0.003613
Fraction of dE00 Between 8 and 9: 0.001002
Fraction of dE00 Between 9 and 10: 0.000013
Image File: roman16_05_magenta.tif
Fraction of dE00 Between 0 and 1: 0.880889
Fraction of dE00 Between 1 and 2: 0.025840
Fraction of dE00 Between 2 and 3: 0.024633
Fraction of dE00 Between 3 and 4: 0.030432
Fraction of dE00 Between 4 and 5: 0.028466
Fraction of dE00 Between 5 and 6: 0.007855
Fraction of dE00 Between 6 and 7: 0.001801
Fraction of dE00 Between 7 and 8: 0.000073
Fraction of dE00 Between 8 and 9: 0.000008
Fraction of dE00 Between 9 and 10: 0.000002
Image File: roman16_06_yellow.tif
Fraction of dE00 Between 0 and 1: 0.723625
Fraction of dE00 Between 1 and 2: 0.152345
Fraction of dE00 Between 2 and 3: 0.062822
Fraction of dE00 Between 3 and 4: 0.028361
Fraction of dE00 Between 4 and 5: 0.018726
Fraction of dE00 Between 5 and 6: 0.013643
Fraction of dE00 Between 6 and 7: 0.000477
Image File: roman16_07_red.tif
Fraction of dE00 Between 0 and 1: 0.705635
Fraction of dE00 Between 1 and 2: 0.070421
Fraction of dE00 Between 2 and 3: 0.023797
Fraction of dE00 Between 3 and 4: 0.021342
Fraction of dE00 Between 4 and 5: 0.025472
Fraction of dE00 Between 5 and 6: 0.039290
Fraction of dE00 Between 6 and 7: 0.097611
Fraction of dE00 Between 7 and 8: 0.016264
Fraction of dE00 Between 8 and 9: 0.000164
Fraction of dE00 Between 9 and 10: 0.000004
Image File: roman16_08_green.tif
Fraction of dE00 Between 0 and 1: 0.507498
Fraction of dE00 Between 1 and 2: 0.034618
Fraction of dE00 Between 2 and 3: 0.068252
Fraction of dE00 Between 3 and 4: 0.249225
Fraction of dE00 Between 4 and 5: 0.098253
Fraction of dE00 Between 5 and 6: 0.030427
Fraction of dE00 Between 6 and 7: 0.009730
Fraction of dE00 Between 7 and 8: 0.001682
Fraction of dE00 Between 8 and 9: 0.000309
Fraction of dE00 Between 9 and 10: 0.000006
Image File: roman16_09_blue.tif
Fraction of dE00 Between 0 and 1: 0.975537
Fraction of dE00 Between 1 and 2: 0.006030
Fraction of dE00 Between 2 and 3: 0.014454
Fraction of dE00 Between 3 and 4: 0.003712
Fraction of dE00 Between 4 and 5: 0.000216
Fraction of dE00 Between 5 and 6: 0.000036
Fraction of dE00 Between 6 and 7: 0.000015
Image File: roman16_10_olive.tif
Fraction of dE00 Between 0 and 1: 0.999515
Fraction of dE00 Between 1 and 2: 0.000393
Fraction of dE00 Between 2 and 3: 0.000080
Fraction of dE00 Between 3 and 4: 0.000010
Fraction of dE00 Between 4 and 5: 0.000002
Image File: roman16_11_brown.tif
Fraction of dE00 Between 0 and 1: 0.998388
Fraction of dE00 Between 1 and 2: 0.001046
Fraction of dE00 Between 2 and 3: 0.000382
Fraction of dE00 Between 3 and 4: 0.000168
Fraction of dE00 Between 4 and 5: 0.000010
Fraction of dE00 Between 5 and 6: 0.000006
Image File: roman16_12_pastel.tif
Fraction of dE00 Between 0 and 1: 0.989521
Fraction of dE00 Between 1 and 2: 0.008827
Fraction of dE00 Between 2 and 3: 0.001144
Fraction of dE00 Between 3 and 4: 0.000340
Fraction of dE00 Between 4 and 5: 0.000153
Fraction of dE00 Between 5 and 6: 0.000015
Image File: roman16_13_coloured.tif
Fraction of dE00 Between 0 and 1: 0.604999
Fraction of dE00 Between 1 and 2: 0.194161
Fraction of dE00 Between 2 and 3: 0.091016
Fraction of dE00 Between 3 and 4: 0.063803
Fraction of dE00 Between 4 and 5: 0.008682
Fraction of dE00 Between 5 and 6: 0.018504
Fraction of dE00 Between 6 and 7: 0.015707
Fraction of dE00 Between 7 and 8: 0.001398
Fraction of dE00 Between 8 and 9: 0.001081
Fraction of dE00 Between 9 and 10: 0.000575
Fraction of dE00 Between 10 and 11: 0.000067
Fraction of dE00 Between 11 and 12: 0.000002
Fraction of dE00 Between 12 and 13: 0.000002
Fraction of dE00 Between 13 and 14: 0.000002
Image File: roman16_14_highkey_BW_rgb.tif
Fraction of dE00 Between 0 and 1: 1.000000
Image File: roman16_15_midtone_BW_rgb.tif
Fraction of dE00 Between 0 and 1: 1.000000
Image File: roman16_16_lowkey_BW_rgb.tif
Fraction of dE00 Between 0 and 1: 1.000000
Image File: PDI_Target-DCP-NoSyn.tif
Fraction of dE00 Between 0 and 1: 0.996751
Fraction of dE00 Between 1 and 2: 0.001693
Fraction of dE00 Between 2 and 3: 0.000258
Fraction of dE00 Between 3 and 4: 0.000108
Fraction of dE00 Between 4 and 5: 0.000579
Fraction of dE00 Between 5 and 6: 0.000069
Fraction of dE00 Between 6 and 7: 0.000039
Fraction of dE00 Between 7 and 8: 0.000503
Image File: PDI_Target-DCP.tif
Fraction of dE00 Between 0 and 1: 0.981506
Fraction of dE00 Between 1 and 2: 0.004536
Fraction of dE00 Between 2 and 3: 0.002734
Fraction of dE00 Between 3 and 4: 0.001290
Fraction of dE00 Between 4 and 5: 0.001831
Fraction of dE00 Between 5 and 6: 0.001291
Fraction of dE00 Between 6 and 7: 0.001522
Fraction of dE00 Between 7 and 8: 0.002415
Fraction of dE00 Between 8 and 9: 0.001438
Fraction of dE00 Between 9 and 10: 0.001136
Fraction of dE00 Between 10 and 11: 0.000301
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Nope it's non color managed and the color appearance is totally out of that users control in such a situation and there is no guarantee of any kind of visual match to sRGB. Without Color Management, sRGB is a meaningless concept.
I agree, I am just not sure why you would waste our time and increase confusion by writing that in the context of the question I was answering for the OP:
Non color managed end user = sRGB. It offers the least likely chance of missing the target altogether.
That's a pretty clear, constructive answer, as for yours... Here's a practical question that goes to the heart of the matter: if we chose a random sample of the video systems of the population at large and put the same sample image through all of them as they are set up, do you think rendering and tagging it in ProPhoto or Adobe RGB would produce better average deltaExx than sRGB?
You know which way I am leaning :)
Jack
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I agree, I am just not sure why you would waste our time and increase confusion by writing that in the context of the question I was answering for the OP:
I may be wasting your time, just speak for yourself. Ditto about your possible confusions.
That's a pretty clear, constructive answer, as for yours... Here's a practical question that goes to the heart of the matter: if we chose a random sample of the video systems of the population at large and put the same sample image through all of them as they are set up, do you think rendering and tagging it in ProPhoto or Adobe RGB would produce better average deltaExx than sRGB?
Yes clear and correct. As to your question and an analogous scenario whereby by picking random people and asking them to throw darts at a board blindfolded, how many may hit the center: some may, some may not; there's no guarantee. EXACTLY the same expecting sRGB without a tag to be understood as sRGB. No guarantee and worse, a guarantee of being wrong on some systems like mine, with out CM. Images in ANY color space can only preview as expected with Color Management. That's a fact you can accept or deny. R45/G69/B149 is a different color in sRGB, Adobe RGB (1998) or ProPhoto RGB on EVERY system you asked about above and can ONLY be properly viewed WITH Color Management.
Non color managed end user does NOT = sRGB. It equals RGB mystery meat. I don’t know if you are purposely trying not to understand this, or if you are really struggling with it.
Jim answered the OP's question before you and I got here FWIW!
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Jim answered the OP's question before you and I got here FWIW!
Yes, that was a pretty good answer. I was however responding to a more direct question that the OP asked later on.
Anyways no harm done, I am still a dog fan ;)
Jack
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Nope it's non color managed and the color appearance is totally out of that users control in such a situation and there is no guarantee of any kind of visual match to sRGB. Without Color Management, sRGB is a meaningless concept.
Cheap portable computers using backlit displays may be better left w/o profiling. I measured one of my laptops and the red is about 25% less saturated than sRGB's primary. Profiled, it clips reds that go beyond its capability. I actually had to use Photoshop's "desaturate" option to bring back clipped red/orange colors that are in sRGB but can't be displayed with my more limited screen.
This is a result of the push for longer battery life because they reach higher brightness for a given backlight intensity with broader RGB filters. So for this laptop, I just removed the profile. Colors are off but at least it's not clipping places I didn't expect. OTOH, I don't use it for color work. Too sensitive to viewing angle as well.
Newer generation, and more expensive oled screens don't have that problem - or so I've heard. Maybe they will increase the demand for color management.
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The attached program displays percentages of pixels that, when converted from either Adobe RGB or ProPhoto RGB to sRGB have their color values clipped in Delta E 2000 steps. For instance if we take all 16M colors in the Adobe RGB space, convert them to sRGB and compare them with Delta E 2000, 61.64% are changed less than 1 Delta E 2000. Another 7% are changed between 1 and 2 Delta E 2000.
Regular photos typically undergo much smaller changes. The supplied, size decreased, venerable KodaK DISC test image as modified by DryCreek has 97.88% of it's colors effectively unchanged and those that are changed are mostly in the added synthetic color gradients added by DryCreek.
The program runs on Windows XP and above. The c++ file as well as executables are included. Source code includes functions for Delta E 2000, converting RGB to XYZ and LAB, and clipping against sRGB. The DLLs must be in the same directory as the executable. Standard wild cards may be used like so which will list the statistics for images matching myimage*.tif that are in Adobe RGB:
tiffreader -1 myimage*.tif
Usage: tiffcolor [-profile#] image1 ... image
profile#: 0 for ProPhoto RGB (default)
1 for AdobeRGB
image[...] tiff image(s)
Example:
tiffcolor ProPhotoImage1.tif ProPhotoImage2.tif -1 adobeImage1.tif -0 ProPhotoImage3.tif
The special image name 'RGB' can be used to show the dE00 distribution of Adobe or ProPhoto RGB from sRGB
The following example shows the dE00 change distribution for the RGB space and a KodaK test image.
tiffreader -1 RGB PDI_Target-DCP_small.tif
output:
Image File: RGB
Fraction of dE00 Less Than 1: 0.616422
Fraction of dE00 Less Than 2: 0.685365
Fraction of dE00 Less Than 3: 0.732556
Fraction of dE00 Less Than 4: 0.769466
Fraction of dE00 Less Than 5: 0.806518
Fraction of dE00 Less Than 6: 0.843115
Fraction of dE00 Less Than 7: 0.881229
Fraction of dE00 Less Than 8: 0.922590
Fraction of dE00 Less Than 9: 0.957754
Fraction of dE00 Less Than 10: 0.988474
Fraction of dE00 Less Than 11: 1.000000
Image File: PDI_Target-DCP_small.tif
Fraction of dE00 Less Than 1: 0.978808
Fraction of dE00 Less Than 2: 0.984694
Fraction of dE00 Less Than 3: 0.988338
Fraction of dE00 Less Than 4: 0.990169
Fraction of dE00 Less Than 5: 0.991774
Fraction of dE00 Less Than 6: 0.993123
Fraction of dE00 Less Than 7: 0.994676
Fraction of dE00 Less Than 8: 0.997110
Fraction of dE00 Less Than 9: 0.998611
Fraction of dE00 Less Than 10: 0.999702
Fraction of dE00 Less Than 11: 1.000000