From Stage3Image() to sRGB color space

I get my image this way dng_image* image = (negative->Stage3Image()); I have to manimulate with it and then I want to covtert it to sRGB color space. I tryed to do gamma 2.2 and white balance with white point from camera, but colors are still different.
I think that I should use this matrix camera2RGB for conversion but I don't know how.
dng_camera_profile* profile = negative->CameraProfileToEmbed();
dng_color_spec spec(*negative,profile);
const dng_matrix camera2RGB = dng_space_sRGB::Get ().MatrixFromPCS () * spec.CameraToPCS ();
profile->HasColorMatrix1(); returns true
profile->HasColorMatrix2(); returns true
negative->HasCameraNeutral(); returns true
Sorry for my language skill
Thank you
Petr Kocich

Broadly, (and speaking from memory) what dng_render does is to convert
into a linear (gamma 1) ProPhoto space, apply a tone curve, etc, then
convert to the final output color space.
The mathematics are conventional color matrix maths. You can find a
lot of references on the web. Including some I wrote : http://chromasoft.googlepages.com/colorspacepapers
The other place to look is at the documentation of CMMs such as
littleCMS: http://www.littlecms.com/
What littleCMS does is exactly the same, if a bit more generalized, as
what the DNK SDK does in regards of color management.
Sandy

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New ICC v4 sRGB Color Space May Prevent Clipping Converting From ProPhoto RGB

Just discovered and tried out this new sRGB color space downloaded from this page:
http://www.color.org/srgbprofiles.xalter
Here's a cropped demo with histograms of a raw image I've been working on in ProPhotoRGB in ACR 3.7 and CS2:
http://www.flickr.com/photos/26078880@N02/2874068887/sizes/o/
Please disregard the PRMG name in the demo. I got confused as to which was which on that site and thought that this version of sRGB was a PRMG=(Perceptual Reference Medium Gamut) profile. It's called sRGB_v4_ICC_preference.icc.
Note the different color shifts using the Perceptual intent and unchecking Black Point Compensation=(BPC). Neat little features embedded in this profile, but not sure about how it renders certain colors close to clipping in the shadows. That site doesn't recommend mixed use of ICC v4 with v2 color spaces and output device profiles but I did it anyway just to see what it does.
Who knows this may be the equivalent of handing scissors to children, but I'm just one of those curious children and thought I'ld share anyway.

I'll try to respond to a few items above.
The digital values in a Pro Photo RGB file should generally be the same as for a ROMM RGB file. The exception is that all possible Pro Photo RGB values are "legal" but not all ROMM RGB values are "legal." ISO 22028-2 restricts the legal ROMM values to those with PCS LAB values between 0 and 100 L* and -128 to +128 a* and b*.
There is no enforcement if you use the illegal values in a ROMM file but as some of these values do not represent possible colors this is not advisable. I think it is good practice to try to stay mostly inside the ICC v4 PRM gamut with Pro Photo/ROMM images. You can check this using the gamut warning profile on the ICC site.
If you have a Pro Photo RGB image you should just assign the ROMM profile to it. Converting to ROMM RGB should not change anything in the ideal sense but there is the possibility to introduce rounding errors and mismatch black points.
The main difference between the Pro Photo RGB profile and the ROMM RGB profile is the former includes black scaling to zero (as is common with v2 color space and display profiles) and the latter does not (as is required with v4 profiles).
In the duck picture, the reason for the difference is the ROMM profile black is at L*=3 so this is where the lowest blacks land when converting MRC to v2 sRGB (which has the sRGB blacks scaled to L*=0). In this case leaving BPC off is analogous to turning on "Simulate Black Ink" in Photoshop Proof Setup.
All the ACR color space choices are v2 profiles with black scaling. If you want a v4 profile embedded you have to assign it (if you have a corresponding v4 profile) or convert to it.
Both the sRGB and PRM gamuts fit within the ROMM RGB legal encoding range, but if you use a v2 profile with black scaling you should always turn on BPC when combining with a v4 profile. Otherwise the v4 profile will think the v2 profile represents a device with an infinite dynamic range. When BPC is on the Color Engine scales the black point of the source profile to the black point of the destination profile.
The sRGB gamut extends outside the PRM gamut in some places, and the PRM gamut extends outside the sRGB gamut in other places. If you convert using a colorimetric intent in either direction some of the gamut will be clipped. The purpose of the sRGB v4 perceptual transforms is to minimize clipping in both directions.
I can't do this justice here but basically scene-referred images are encodings of the scene colors and output-referred images are encodings of the picture colors on some medium for which the picture colors have been optimized. You can make a scene-referred image by setting the ACR sliders (except the white balance sliders) to zero and the curves tab to linear. You make an output-referred image when you adjust the sliders to non-zero values to make a nice picture as viewed on some medium. For example you might adjust the sliders differently to get the best results printing colorimetrically on glossy photo paper vs. on plain office paper.
Often an important part of the transform to output-referred includes a midtone contrast and saturation boost. While there will likely be some highlight and may be some shadow compression, it is misleading to think of this transform only as a compression to some output medium dynamic range. In some cases the output medium dynamic range is larger than that of the scene.
Usually the transform to output-referred is more complicated than a simple gamma function.
Regardless of the image state (scene-referred or output-referred) the sRGB, Adobe RGB, or Pro Photo RGB nonlinearities will be applied to create the image data that you open into Photoshop.
We are working in the ICC to prepare more information for posting on this topic.

SRGB monitor and SRGB color space in After Effects

Hello, I would like to ask some really basics about color correction. I do mostly animations and editing that plays on web and television sometimes. Im using a dell 2713hm monitor. Should i use the sRGB profile when i color correct? Also should i set my After Effects also to sRGB color space? thanx

My monitor comes calibrated in sRGB i think. But in any case, i m getting the spy4elite tool these days so will fix this issue.
So lets suppose it is. And please lets keep the explanation as simple as possible, cause i have read A LOT and i got confused.
From my understanding when having 8bit and i need to export for web, i should use the sRGB both in profile monitor, in AE color management and in output module? If that is correct, i wanna know what i do when i do 32 bit compositing, and also what i do when i got things for television (either motion graphics/3d or footage)
thanx

How do I save images into an sRGB color space?

Hello,
I'm trying to do this to a batch of images. I'm not up to writing scripts.
But I can't even convert one RAW image to an sRGB color space.
Any thoughts?
Much appreciated!
Matt

There's a link at the bottom-center of the Camera Raw dialog. Click it and you'll be able to set the color space for output of the conversions.
-Noel

Question: sRGB color space profile icm

I am trying to convert a file to color space sRGB color space profile.icm. The profile is located in my library on my hard drive under recommended profiles but it does not appear in the drop down menu under edit/convert to profile. Any ideas about why? I have performed this task on my MAC at my college but can't seem to do it on my MAC in my studio...

LR converts them to the colorspace specified on the Export panel. There are several choices, including sRGB. You may need to expand various sections to see the option.

Srgb color space question

Does Lightroom convert jpg files to srgb color space when exporting?

LR converts them to the colorspace specified on the Export panel. There are several choices, including sRGB. You may need to expand various sections to see the option.

DreamColor Monitor from PC via VGA: Color-Space & Settings?

Context:
Premiere CC on a WIndows 7 laptop with an external DreamColor monitor connected via VGA port (for convenience rather than bit depth).
What color space is appropriate in the DreamColor settings, i.e. what is the VGA likely to be supplying? DreamColor's config options are: [ Full | AdobeRGB | Rec.601 | sRGB | Rec.709 | DCI P3 Emulation ]. I'm guessing sRGB, but is that reasonable e.g. is it the Adobe kind?

Several questions spring to mind ... first, are you calibrating this with an actual "real" calibration tool, such as the i1Display units, anything? Because ... if the answer is no ... well, the output isn't set to any particular "there" before you even start, is it?
Next ... what are you going to be outputting for? B-cast TV? Critical web use? Your own YouTube/Vimeo channel for the heck of it? Family records? Whatever is going to be the "heaviest" output (meaning demands on color space) sets the minimum from what your choices can offer. Critical web work or such, you would either want the Adobe RGB or the Rec.709 I would think. For just fun stuff, the sRGB would work ok.
Fwiw ... Adobe RGB is a wider color space than "standard" sRGB. Rec.601 & Rec.709 are "broadcast" standards that include specialized base/gain/gamma settings. Rec.709 is the newer and far more common one of the two ... and it sets "black" as at value (in 8-bit terms) of 16 and "white" at 235. Data outside those values are used for technical purposes within the "system". Some modern video cams record in Rec.709, btw.

Color Space Issue with Wide-Gamut monitor

Since getting my new (and carefully calibrated) LaCie 324 monitor, I have noticed that RAW (and maybe other) images exported from Lightroom as
sRGB jpegs look washed out and slightly green when viewed outside of Lightroom (IE8, Firefox, ACDSee, windows 7 viewer). It seems not to matter whether the external application horors embedded color space profiles or not, since the unmanaged ones assume sRGB.
When I bring one of these jpegs into PhotoShop it still looks bad, and not what I see in Lightroom. However, if I Assign the Adobe RGB profile to the image, it immediately looks like the Lightroom version. And if I then Convert that image to sRGB and save it, it looks fine everywhere, even on an uncalibrated standard Dell TN LCD display.
Any ideas what I might be seeing here. A friend with the same monitor has the same problem, which is what is leading me to suspect the monitor.
The first image here is converted from Lightroom with sRGB color space. The second was first assigned the Adobe RGB color profile and then converted and saved out again as a jpeg.
Converted Only

I downloaded and ran the program. My version number appears to be 2.1 if I read the numbers right.
I am still at a loss as to why my sRGB jpegs only look right if I assign the wrong profile to them.
Here are the settings in Windows 7 for color management. The highlighted profile is the one just created for my monitor. Display 2 is my main display. Note the "viewing conditions" setting on the advanced tab. Do you think the rendering intent might be at fault here? In Lightroom, should I use Perceptual over Relative or vice versa?

MPB 17" and what Adobe RGB color space coverage I might expect from it

Hello,
I am photographer and currently PC user. However, I plan to dive to the Mac’s world.
Before I become a Mac user, I have few questions.
Now I think about MacBook Pro 17”, i7 2.66MHz, 8GB RAM, 500 GB 7200rpm HDD and antiglare screen.
I plan to use additional monitor for photo editing.
I did search on google about *NVIDIA GeForce GT 330M* and *Adobe RGB color space* it covers, however, it gave me no results related to Mac. The only information about this card and Adobe colors I found is that Sony Vaio use this graphic card and in some forums, one say it covers 98% and in other 100% of Adobe color space which made me wonder what type of screen Vaio have.
- is MacBook Pro 17” good for photo editing?
- what % of AdobeRGB color space I might expect from it on my external screen or what % of sRGB colors space it delivers?
- Is it possible to calibrate Mac’s native screen and external one, use both at the time and have different profiles on each?
- Tell me anything that would stop me thinking about MBP for photo editing?
Thank you for your time reading this and hope to find the answers here.

You should consider posting your questions in the Pro Application section for Aperture. You will bump into more photographers there than you will here. But I will make an attempt at answers:
whats about Adobe color space?
No, the MBP screen will not encompass the Adobe Color Space. In fact, few desktop monitors are capable of this.
does the native MBP screen display full color range the video card is able to produce...
There really is no limit to the color extremes, which define a color space, as established by a graphics card. So your question is not a well formed question. An old ATI Rage card with 8-bit output would reveal the same color gamut as would the NVIDIA GeForce GT 330M connected to the same display. The gamut is determined by the attached display, not the graphics card.
...or connecting external monitor to it’s mini display port would bring much wider color range to my eyes?
Yes, certainly the potential for that exists. Notebook screens are usually a compromise and can't be expected to compete with a high-end desktop display in many categories, including color gamut. But whether it would bring a "much wider color range to" your eyes is hard to say. It depends on what type of external display is in use.

RGB color space in LR3 - does it convert back to sRGB on export?

First off, I've only had LR3 for two days so I am a complete novice. I've been reading my book and just came across the part about RGB color space. I shoot with and use sRGB, which apparently LR will recognize. However, it states that the develop module uses Lightroom RGB. My question is, when I export my edited photos to PSE8 (or to a folder on my desktop to save and email for my daughter's business), does it export them back as sRGB? I know there is a lot of controversy over the whole RGB thing, but after my research on the matter, I have decided that sRGB is the best for my particular situation. I'm just making sure I don't have to check something or convert them back if they don't automatically change out of LightroomRGB.

ColeeLou2,
Some additional thoughts to what has been said already:
I shoot with and use sRGB, which apparently LR will recognize.
The color space you chose on your camera (sRGB, AdobeRGB) only affects the JPEG rendering in your camera. It does not affect the RAW file, as a RAW file is not in any color space. Upon import of a RAW into LR, it will be rendered in a ProPhoto RGB color space with an sRGB tone curve (Jao will correct me if I'm wrong ) for use within LR.
My question is, when I export my edited photos to PSE8 (or to a folder on my desktop to save and email for my daughter's business),
I would suggest using an sRGB color space upon export for external uses (like emailing to your daughter), but use ProPhotoRGB when going into PSE in external edit. This way you will have all the color information possible available in PSE, and PSE will recognize the ProPhotoRGB color space.
Beat Gossweiler
Switzerland

The availability of color space in RAW, TIFF and JPEG files

This is useful if your new to DSLR photography.
This is Nikon response on my question in the discussion: View photo metadata
I'm assuming that you know that Adobe RGB shows about 50% and sRGB 35% of CIELAB color space.
In a DSLR camera like the Nikon D800 you can select a color space (Adobe RGB or sRGB) in the shooting menu.
In Adobe Lightroom 4.3 the RAW metadata shows no color space info. Therefore I asked why not?
In the (Dutch) Nikon D800 manual on page 84 (about RAW) and 274 (about color space) and Nikon FAQ website there is no descripton about the color space availability/behavior in RAW, JPEG and TIFF files.
In the book "Mastering the Nikon D800 by Darrel Young" on page 125 - 126 is written: "If you shoot in RAW format a lot, you may want to consider using Adobe RGB....."
All experts on this forum answered: color space does not apply/affect the RAW data file or RAW files have no color space.
The respone of Nikon Europe Support (Robert Vermeulen) was: In Nikon D800 NEF RAW files both color spaces (Adobe RGB and sRGB) are always physically available. In JPEG and TIFF files only the in the shooting menu selected color space is physically available. So the forum experts gave the correct answer!
Of course you can convert afterwards a JPEG or TIFF file with sRGB color space to Adobe RGB but you don't get more colors.
When you install the Microsoft Camera Codec Pack or FastPictureViewer Codec Pack they only show color space metadata for JPEG and TIFF files and nothing for RAW because color space "doesn't exist". I thought the codec packs removed the color space metadata for my RAW files.
Adobe Lightroom also can not show color space for RAW files because that "doesn't exist".

Van-Paul wrote:
The respone of Nikon Europe Support (Robert Vermeulen) was: In Nikon D800 NEF RAW files both color spaces (Adobe RGB and sRGB) are physically available. In JPEG and TIFF files only the in the shooting menu selected color space is physically available.
I still think this is an evasive answer that doesn't really pinpoint the exact chain of events that take place. They are:
1. The raw file contains the naked data captured by the sensor. This is just a very dark grayscale image.
2. In the raw converter it is encoded into a working color space to process the information. In Lightroom this is known as "Melissa RGB", or linear gamma Prophoto. It is also demosaiced to bring back the color information.
3. From Lightroom it can be exported to one of the familiar color spaces like sRGB or Adobe RGB. This is, in principle at least, a normal profile conversion.
These three steps are what the camera does to produce a jpeg. So the basic steps are the same, the camera is just doing it automatically (and usually butchering the image in the process...).
This Darrell Young is, I'm sure, an excellent photographer, but in this he is seriously confused and just propagating a common myth. Anyway, thanks for bringing up this discussion, hope you didn't object too much to the tone of the answers... Our only concern here was to get this right and with no room for misunderstanding.

Color problem with ProPhoto RGB color space

Hi, everyone,
I have wery special problem I think. I use MacBook pro 15" with retina display, adobe Photoshop CC and when I export RAW (from Nikon D7000) from Lightroom 5 to Photoshop with settings: 16 bit TIF, color space: ProPhoto RGB I have a problem with displaying the correct colors. As you can see in this picture:
My problem are some "green" artefacts in absolutely black and white picture. I tried myself to solve this problem and found the following facts: when I convert picture into Adobe RGB or sRGB color space is everything OK - without green artefacts.
But here is one important fact: I have calibrated monitor by datacolor spyder4elite and problem with ProPhoto RGB incorrect color displaying is only when the color calibration configuration is loaded. When I change my display calibration to standard apple color LCD profile than is everything OK.
But using uncalibrated monitor and also Adobe RGB color space are no right solutions for me.
My question is why I have problem with displaying ProPhoto RGB color space in photoshop under calibrated monitor profile and can anybody help me please?
Thanks for answers.

That's a classic example of the basic problem with 16 bit color. There is no solution that I know of.

Color space problem/confusion

I posted the following message to another thread, but at the recommendation of a member I am starting a new thread here. For a couple of answers see the thread below.
http://forums.adobe.com/message/3298911#3298911
I will provide much more information hoping an Adobe support person will chime in. This is extremely odd.
System: HP, AMD, Windows 7 64-Bit, Nvidia 9100, all updates to Windows, latest Nvidia 9100 driver
Display: Samsung 226CW, Windows settings 32-bit color, correct resolution,
Calibration: Done with ColorMunki, D65 target, done after monitor has been on for more than 30 minutes
Personal: (I am adding this information with some hesitation, please excuse it if it sounds like I'm bragging; I am not). I have multiple posts on my blog, have made many presentations on color managed workflow and am very comfortable with the settings in Photoshop and Lightroom. Please take this only as a baseline information, I am not bragging. In fact, I am begging for information!
Problem:
Any, I mean ANY, original JPEG image in sRGB space coming out of the camera with no adjustments, any PSD file in sRGB space, any TIFF file in sRGB space look significantly paler in Lightroom and in Photoshop CS5 than they look in other Windows based image viewers like FastStone or XnView. This should not need these applications to be color space aware, but the situation is the same with or without their color managment turned on or off. I have done the following:
1. Totally uninstalled Lightroom 3 and reinstalled it
2. Recreated a brand new Lightroom catalog/library and reimported all the images, converting all the RAW files to DNG (just in case!)
3. Recalibrated the display
When I view a file, any file and I will use for the sake of simplicity a JPEG file in sRGB color space, in Lightroom it looks pale. Since the file is in sRGB color space, I have verified this, the rendering in Lightroom should be the same as rendering in anything else. But it is not. I took my monitor and connected it to this system with the same odd behavior of rendering in Lightroom being much paler than outside. It appears as if I am viewing an image in Adobe RGB in a windows viewer that is not color managed.
I further tried the following:
1. I copied various versions of one file, all in sRGB color space. One PSD and two JPEG files from the folders of the above system and copied them to my system, Intel, Windows 7 64-bit, display calibrated and profiled with ColorMunki to the same standards as the problem system above.
2. Imported them to Lightroom on my system
3. The rendering in Lightroom is identical to rendering outside Lightroom for all the files and all are same as the rendering in FastStone on the problem system. Outside rendering was done using FastStone as on the problem system.
My deduction is that something on the problem system outlined in the opening of the message is interfering with the Adobe rendering engine and I have no idea what it could be. I WILL GREATLY APPRECIATE if an Adobe engineer could chime in and steer me in the right direction. I am willing to try other things but I have run out of ideas despite the fact that I have reduced much of the problem to the lowest common denominator of sRGB and JPEG against a PSD in sRGB.
Waiting anxiously of your help.
Cemal

Also, I know enough to calibrate a monitor when it is connected to a new computer. That said, even without calibration the behavior should have changed to display all the images in question the same but perhaps with somewhat off colors. Am I right? I am not arguing the point, I am rhetorically raising the question. If the 226CW is wide gamut and 244T is not, when I connect 244T on the same computer the wide gamut issue should be eliminated, should it not? I am not talking at this point about the "correct" color, but the same color in or out of Lightroom.
Unfortunately when you connect another monitor to a computer and don't calibrate or manually change it, Windows will not change the monitor profile. Macs will autodetect and change the profile but this innovation has not reached windows yet. The behavior you observe is caused by managed apps using the monitor profile and unmanaged apps not. If the monitor profile is not changed, the behavior doesn't change.
BTW, for a "cheap" software to be color space aware it does not need a quantum leap in technology I believe. It simply needs to know how to read the ICC profile and the LUT, is that correct?
It's extremely simple to program color management into apps. Standard API libraries have been available in Windows for over a decade. The reason why this hasn't happened is related to the fact that Microsoft hasn't made IE color managed and the software makers do not want to confuse folks when images look different in their program vs IE. Considering that this still is the biggest issue people wrongly complain about in every color managed application (just check Photoshop fora) that is maybe not that strange.

Color spaces in AWT and JAI

Hi,
I am trying to build a image editing application that
supports color management. I am using Swing, AWT, and
JAI 1.1.2. Unfortunately, the most recent tutorial I
could find is about JAI 1.0.1, and a bit outdated.
Does anybody know where I can find a newer tutorial?
The problem I'm having is related to color spaces.
I would like the user to select from a variety of
color spaces like Adobe RGB, Bruce RGB, etc., etc.
These spaces are not supported by default, so it
seems, and I couldn't find a way to define them
myself. Of course I want the TIFF/JPEG readers and
writers to be able to recognize these spaces if their
profiles are embedded, and to include these profiles
when writing images.
Any help or references?
Thanks!
Job Honig

Well, I have the same problem, sort of.
You can get the jpeg profile from the EXIF information of the file (http://www.drewnoakes.com/code/exif/) so you at least know what is coming in. This will work for jpeg, not for tiff (I think).
However, I didn't manage to find a way to create a buffered image for the right profile. You can create it as a default, which is sRGB, or as CS_LINEAR_RGB etc, but did not managed to get a straight correlation between the color space of the image and the ICC profile of the input.
Than, I tried to use ColorConvertOp to convert from the input space to the output space, by using
ColorConvertOp convert = new ColorConvertOp (srcCspace, dstCspace, new RenderingHints( RenderingHints.KEY_COLOR_RENDERING , RenderingHints.VALUE_COLOR_RENDER_QUALITY));
But somehow the results when printed do not look correct.
Didn't manage to find any good example on how to take in one space (like ADOBE RGB 1998) and put it in a PDF file so it will print in the exact color space (either directly, or by converting it to XYZ, whatever).
Anyway, if you have any success here, I'll be happy to know...
-Yishai

Do I need to harmonize color space between LR and other photo editing programs.

I perform the majority of my editing work in Lightroom. However, I also use some 3rd party applications (e.g. Nik, OnOne, etc.) in addition to Photoshop for special editing, etc. I've noticed that the default color space for each of these applications is different. Some default to Adobe RGBb, other sRGB and still others Pro Photo RGB. Should I be using the same color space and bit depth across all of these programs? When I export from LR, should that color space be the same as everything else? I have noticed that when I export some images and take them to a retail store based print service that the colors appear dull and drab. I believe that is because those mass producing print services don't read the color space in the JPEG correctly. Does any of this make sense, or am I way off? Thanks for everyone's input and time.

For your editing workflow, best is to keep the image in the same color space at all time. For final export you should convert to desiered space... for example sRGB for web, adobeRGB for print etc.

From Stage3Image() to sRGB color space

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