At first, here is a great article about color gamuts:
TFT Central: The Pointer's Gamut
The color management systems are great but they are so automatic that if I have a picture that was created with larger gamut than my monitor has, it's nearly impossible to actually see what are the colors that my monitor is missing. The 'relative intent' is the best of rendering intents to see that and even with it you only see problems if the colors are way way off.
In photo editing software there is a feature called 'gamut warning' that shows out-of-gamut colors as a special color. Problem of course is photo editing software is an expensive way to experiment. They are not cheap. The simplest way would be if there is a rendering intent made for that special purpose but there isn't.
Now when with 4K HDTV standards we are finally getting a larger gamut Rec.2020, what are we missing in current Rec.709? It is impossible to test that with videos because they are already filmed in Rec.709 or smaller gamut. Only way to find that out is seek for photos taken, edited and released in bigger gamuts like AdobeRGB or ProPhotoRGB.
The problem with current Rec.709 ( and sRGB ) gamut in photos is the gamut has already been shrank smaller. It isn't possible to make it wide again. Depending on how the film is edited, the gamut may have been shrank with 'relative intent' when out-of-gamut colors look 'burned' or with 'perceptual intent' or others like 'perceptual intent' when shrinking the gamut also affects colors that were already inside gamut.
That may be the problem when I'm calibrating my displays. Even when I calibrate the white point and primaries correct, that doesn't make the colors right because they might have been undersaturated already in postprocessing of the movie. That is why the colors that are closest to white point D65 also look the best (IMHO).
You could oversaturate your calibration to compensate but the problem of course is there is no common agreement or standard how the undersaturation might have been done in postprocessing so you would be guessing.
But we can of course try to understand what we are missing. There is a program jpegicc.exe that is in Cygwin's lcms-package. Lcms(Little Color Management System) is a library that supports Gamut Warning and jpegicc.exe is a utility that uses that library. (Go install it ), LittleCMS uses gray color for gamut warning.
Then you can create run.bat that contains:
"C:\cygwin\bin\jpegicc.exe" -v -p "C:\Windows\System32\spool\drivers\color\sRGB Color Space Profile.icm" -g -t 1 -m 1 %1 %1.sRGB.jpg
This batch file then takes nmae of the picture file as parameter and creates another picture file with a ".sRGB.jpg" added in the end of file name.
If you are already using Linux I'm quite sure you can figure out how to run this in it. Little CMS web site contains sRGB profiles if you cannot find them in your system.
Here are some example pictures I found that have larger gamuts and actually use them. Al these pictures have gamut warnings somewhere. Because I don't own the rights for these pictures, I only link them here. I have no knowledge how much these pictures where altered from original ones either.
https://secure.flickr.com/photos/wili/295189351/
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/33/IMG_0107.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/IMG_6948.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/IMG_9693.jpg
http://blog.dominik.ca/wp-content/gallery/25mm_sample_1/graffiti_wall.jpg
http://meyeryu.files.wordpress.com/2011/01/prgb_img_5871.jpg
http://rlcaronblog.com/wp-content/uploads/2012/12/RLC0291.jpghttp://desudesign.com/wp-content/uploads/2012/03/Simple_8774-Edit-AdobeRGB.jpg
http://stevemccurry.files.wordpress.com/2014/07/spain-10051-1.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/_MG_9902.jpg
http://fashionwordl.files.wordpress.com/2012/02/mg_9438-300dpi-30cm-alto-adobe-rgb-baja.jpg
http://fashionwordl.files.wordpress.com/2012/02/mg_9929-300dpi-30cm-alto-adobe-rgb-baja.jpg
http://meyeryu.files.wordpress.com/2011/01/prgb_mg_8193.jpg
http://jamiedentontandp2b.files.wordpress.com/2012/02/pro-rgb.jpg
WARNING:Nudity
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_04_AdobeRGB1998.jpg
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_05_AdobeRGB1998.jpg
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_08_AdobeRGB1998.jpg
TFT Central: The Pointer's Gamut
The color management systems are great but they are so automatic that if I have a picture that was created with larger gamut than my monitor has, it's nearly impossible to actually see what are the colors that my monitor is missing. The 'relative intent' is the best of rendering intents to see that and even with it you only see problems if the colors are way way off.
In photo editing software there is a feature called 'gamut warning' that shows out-of-gamut colors as a special color. Problem of course is photo editing software is an expensive way to experiment. They are not cheap. The simplest way would be if there is a rendering intent made for that special purpose but there isn't.
Now when with 4K HDTV standards we are finally getting a larger gamut Rec.2020, what are we missing in current Rec.709? It is impossible to test that with videos because they are already filmed in Rec.709 or smaller gamut. Only way to find that out is seek for photos taken, edited and released in bigger gamuts like AdobeRGB or ProPhotoRGB.
The problem with current Rec.709 ( and sRGB ) gamut in photos is the gamut has already been shrank smaller. It isn't possible to make it wide again. Depending on how the film is edited, the gamut may have been shrank with 'relative intent' when out-of-gamut colors look 'burned' or with 'perceptual intent' or others like 'perceptual intent' when shrinking the gamut also affects colors that were already inside gamut.
That may be the problem when I'm calibrating my displays. Even when I calibrate the white point and primaries correct, that doesn't make the colors right because they might have been undersaturated already in postprocessing of the movie. That is why the colors that are closest to white point D65 also look the best (IMHO).
You could oversaturate your calibration to compensate but the problem of course is there is no common agreement or standard how the undersaturation might have been done in postprocessing so you would be guessing.
But we can of course try to understand what we are missing. There is a program jpegicc.exe that is in Cygwin's lcms-package. Lcms(Little Color Management System) is a library that supports Gamut Warning and jpegicc.exe is a utility that uses that library. (Go install it ), LittleCMS uses gray color for gamut warning.
Then you can create run.bat that contains:
"C:\cygwin\bin\jpegicc.exe" -v -p "C:\Windows\System32\spool\drivers\color\sRGB Color Space Profile.icm" -g -t 1 -m 1 %1 %1.sRGB.jpg
This batch file then takes nmae of the picture file as parameter and creates another picture file with a ".sRGB.jpg" added in the end of file name.
If you are already using Linux I'm quite sure you can figure out how to run this in it. Little CMS web site contains sRGB profiles if you cannot find them in your system.
Here are some example pictures I found that have larger gamuts and actually use them. Al these pictures have gamut warnings somewhere. Because I don't own the rights for these pictures, I only link them here. I have no knowledge how much these pictures where altered from original ones either.
Buildings etc.
http://blog.james-pratt.com/wp-content/uploads/2014/03/2005-0903-0184.jpghttps://secure.flickr.com/photos/wili/295189351/
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/33/IMG_0107.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/IMG_6948.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/IMG_9693.jpg
http://blog.dominik.ca/wp-content/gallery/25mm_sample_1/graffiti_wall.jpg
Nature
http://album.foto.ru/photos/or/114625/3319242.jpghttp://meyeryu.files.wordpress.com/2011/01/prgb_img_5871.jpg
http://rlcaronblog.com/wp-content/uploads/2012/12/RLC0291.jpghttp://desudesign.com/wp-content/uploads/2012/03/Simple_8774-Edit-AdobeRGB.jpg
http://stevemccurry.files.wordpress.com/2014/07/spain-10051-1.jpg
http://www.lux-et-color.ru/wordpress/wp-content/uploads/stream/25/_MG_9902.jpg
People
http://fourthirds-user.com/images/204/E-P1-fromRAW-AdobeRGB.jpghttp://fashionwordl.files.wordpress.com/2012/02/mg_9438-300dpi-30cm-alto-adobe-rgb-baja.jpg
http://fashionwordl.files.wordpress.com/2012/02/mg_9929-300dpi-30cm-alto-adobe-rgb-baja.jpg
http://meyeryu.files.wordpress.com/2011/01/prgb_mg_8193.jpg
http://jamiedentontandp2b.files.wordpress.com/2012/02/pro-rgb.jpg
WARNING:Nudity
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_04_AdobeRGB1998.jpg
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_05_AdobeRGB1998.jpg
http://tricjastyling.com/wp-content/uploads/2014/02/IC_LottePOTY_08_AdobeRGB1998.jpg
Comments
Post a Comment