Illustrator SDK converts LAB to CMYK, how to avoid?

When I examine an object's colour using the Illustrator SDK, the colour always seems to be CMYK or RGB, even if it's a LAB colour in the UI.
How can I get at the LAB colour data and avoid the conversion to CMYK?

Hmmm. I don't know the C# interface at all, but I assume its got some differences, and this might be one of them. In the C++ API, the fill colour is an AIColor object, which contains a union of RGB, CMYK, etc. One of the union is AICustomColorStyle, which contains two members: a AIReal tint value, and an AICustomColorHandle color. Using the latter, I can ask for the custom colour and from that I can get an AICustomColor object. This looks very similar to the AIColor struct, but its union only has CMYK, RGB, greyscale & LAB -- which as far as I know only appears there.
So if that was C++ code, I'd look at pathItem.FillColor and it would (hopefully!) be labeled as a custom color (kind == kCustomColor). From there I'd use the handle to look it up and then I'd ask the AICustomColor object I got back if it's kind member was kCustomLabColor. I'm not sure what the equivalent in C# is though. Is there a CustomColor type you can check for? Maybe it needs to be converted into that first? I only know any of this because I added support for spot colours & LAB colours last year to our product, and I found the strange AIColor/AICustomColor similarity confusing when I was first using them. It felt weird to use a colour to look up a colour, especially when what you got back looked almost exactly the same as what you'd first got. Maybe there's something like that at work in the C# API?

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Convert rgb to cmyk in bridge

I am working on a MAC & Photoshop CS2. I
need a how-to action for converting RGB
to CMYK & how to image process it in Bridge.
Many thanks.

If you create an RGB>CMYK action in Photoshop you can easily pick images in Bridge and call up a Batch operation from within Bridge...but it's Photoshop doing the work cause Bridge ain't an image processor (as others have said).

I just purchased photos from shutterstock and they said it will download as .eps file. They said I would need vector editor such as adobe illustrator to convert the image to a jpeg. Could anyone advise me how to do this? This is all very foreign to me. Th

I just purchased photos from shutterstock and they said it will download as a .eps file.They said I would need vector editor such as adobe illustrator to convert the image to a jpeg. Could anyone advise me on how to do this? This is all very foreign to me.
The Swanky Lady

File>Open to open your eps file
File>Export to export your image as a jpg.
In the export dialog box just below where you type in the filename is a file type, that is where you choose jpg.
What ever you do, do not delete the eps file. Should you ever need to access the original you will have have.
I recommend that instead of jpg you choose psd, tiff, or png and use jpg only for sharing. Jpg is a lossy format meaning each time you edit the file and save it, the quality of that file degrades. The formats I recommend are lossless formats, you can edit them all you want no data is being discarded unless you choose to do so.

'greyscale' RGB image, need to convert to specific CMYK black... how?

Hi,
I have an image provided in RGB, but visually it's greyscale, except for some red areas on certain clothing. I need to convert it to CMYK, and I want all the black areas to be 40/30/20/100, and the grey values should be percentages of this mix. The red should be visually unaltered. Im using CS3 btw.
Is there a way to quickly do this? I can convert to a generic CMYK value then tweak the curves of each channel, but it will affect the red. I could make a selection to exclude the red, but i feel there must be a way for me to define my black, and convert, and for my wishes to be granted automagically.
I tried redefining my default black in the foreground/background swatches, but that had no effect on the subsequent conversion.
Also, I'm trying to avoid profiles as my brain is foggy in that area...
Thank you,
Simon Gregory

Without seeing the image, it might be a shot in the dark, but what about creating a new CYMK document, of the same size as the RGB one. Add a layer filled with the 40/30/20/100 black.
Go to the RGB image, In the Channels panel, drag the red channel to the new channel icon. Drag this new channel to the CYMK channel panel. Add a layer mask to the 40/30... layer. go back to the channels panel, and target only the copied channel, copy it, target the layer mask channel, paste. Target the Layer mask, invert it.
Now, select and bring the red part from the RGB image, and you should be good to go...

Lack of LAB and CMYK support in Lightroom is plain dumb

There is a lack of consistency in Lightroom if it allows you to elect to edit an image in Photoshop but then it can't follow through and display either a LAB PSD or a CMYK PSD. Both these file types are widely used by Pro-photographers. Afterall there is a whole bunch of stuff that's easier to do in Lab or CMYK rather than in RGB. The lightroom development team seem to suggest that photographers shouldn't be doing anything more advanced than Lightroom can handle. Well if you look at pre-print sharpening Lightroom is still awful - LOW/MED/HIGH just doesn't cut it and isn't at anything like pro level. To get any sensible preprint sharpening you've almost gotta go to photoshop. For many images sharpening is best done on the L channel of Lab (along with a whole bunch of other adjustment layer corrections). Most people like to keep these layers and so returning a master file to RGB just isn't an option. Sure there is no further need for editing such an image in Lightroom, but as part of Lightroom's function is DAM then its fairly essential to be able to at least preview all your image files - to know where they are and what you have.
Its just no good boasting about Lightroom's ability to search through images using metadata etc if ultimately it can't find and display your -finished- image versions 'cos they just happen to be Lab or CMYK PSDs.
If Adobe Lightroom team are promoting Lightroom as a pro-photographers tool them you gotta listen to how pro-photographers work and not get lost in your own ideology based rhetoric of keeping Lightroom pure. I haven't yet found two pro-photographers with identical "pure" workflows.
Come on Adobe - we don't want to edit them - we just want to be able to preview them in Library ;-)

Have to say as a working professional who earns his keep from doing raw conversions, proof prints, cutouts etc Lightroom's lack of CMYK support is very much a pain in the a**. I'm not asking for a full set of CMYK editing tools - I've got those in Photoshop thanks very much.
What I am asking for is at least the ability to round trip files from Lightroom into Photoshop, convert to CMYK and reimport the CMYK version into the catalog alongside the RGB file from which it originated and then to allow me to open the original CMYK file back into Photoshop without any tweaks being applied by Lightroom. This would allow Lightroom to really fill the role of a DAM in our studio and allow us much simpler workflow tracking than at present. As things stand we have to save the files in separate locations from our RGB versions on our server and then catalog them using another application.
Come on Adobe please listen to your professional user base as I know I'm not alone in these requiements and the studios that I've shown Lightroom to have all ended up asking the question "What about the final CMYK versions?"
BTW I'm in full agreement with Ian on the other points and without sounding snotty to Don - who I have read many interesting and sensible posts from - maybe if you don't want to cover this ground again just walk a different direction and leave those of us who do NEED this feature to discuss the best way of implenting it. I have also sent this request to Adobe so I'm not just a moaner who sit's here doing nothing about the issues that affect me.
Cheers for now.
Jason Hicking
Replica Imaging Limited - UK

Issue converting PMS to CMYK

I'm using Illustrator CS5 / Mac OS 10.6.8
Ihave a customer supplied file that has several placed grayscale .tif images in it. The images are colored with a spot PMS color. We are going to run the job CMYK. So I go into my swatches palette, select the spot color, and change it from Book Color to CMYK, and then from Spot Color to Process Color. When I do, the image turns black. If you click on it it still has the correct color applied to it. It's just black instead of the color it's supposed to be.
I've tried just clicking on the image, going to the color palette and converting it to CMYK there. Same result. I've tried changing it to a different color. It still stays black but when you click on it it says it's whatever color it's supposed to be.
I've also tried converting the color to LAB and RGB just to see if that made any difference. The grayscale still turns black.
Tried printing it, figuring it's just a weird display issue, but it prints black as well.
This only effects grayscale images. If I create a vector shape of the PMS color and then change the color to CMYK it works as it should.
I'm stumped. Never seen this before. Anyone have any ideas?

It is in CMYK mode. The blending mode is 100% and Normal. It was originally a CS5 document.
The color change is big. The color is PMS 583. I also tried copying the image and putting it into a brand new document. Same issue.
Here is a screen shot with the grasycale image with a spot PMS applied - it's the box with the "OUR NO LIST" in it.
Here it is when I change the color from PMS to CMYK:
Notice it's still selected, and the color applied to it says it's a CMYK color, but it's black.

Does Lightroom convert images to CMYK?

I need to convert images to CMYK to submit photos for an article. I know Photoshop will convert, but don't know which software. If Lightroom does not convert to CMYK, which would I need to get?

p3vanisle wrote:
So I can locate the CMYK profile my printer is using, and install it into my design suite (PS, Illustrator, InDesign) and then export relevant filetypes in that color space? That would be terribley useful.
Yes, you have to install the profile on your computer. In Photoshop CSxx you go >Edit >Convert to Profile, and select the CMYK-profile under <Destination Space>. In Acrobat you go >Edit >Color Management, and select the profile under <Working Space>. But only Photoshop will convert the image to CMYK, whereas - at least for my understanding - Acrobat will display the image as if it were CMYK but not actually convert it.
If I do the conversion here (open their images in PS or Acrobat and convert the profile) aren't I still stuck in the 'I don't know what shade of pink you want that flower to be' still anyways?
If you get a RGB image from a client, you have to assume that the colors are as wanted. This is not different when you get a CMYK image. The problem for you is that nor everybody has a calibrated monitor, so an image might look good on their monitor but the actual color numbers will produce a print that looks different. But there is nothing you can do, except - if you have the time - adjust obvious off-colors. For instance you know the skin-color of caucasian (white) people. You know how green a lawn is, and you know that most brides wear a white gown. So if for instance the gown is blue-ish, or the skin looks overly pink, you can adjust that. More you cannot do. In case of a flower you can only accept the photo as is - unless you know this type of flower very well.
But the evaluation of color is only possible if you have a calibrated monitor that is re-calibrated regularly (every week or so). If your monitor is not calibrated you have no way of knowing if the off-color is due to the color numbers of the delivered image or a result of your un-calibrated monitor that displays the colors differently than the color numbers warrant.
If you use a calibrated monitor the colors should not change on conversion to CMYK. You can use the Softproof feature in Photoshop to check if colors are out of gamut.
- my degree is in design, yes, but we didn't cover printing and prepress specifics at all.
Yes, I have noticed in my work that the designers often have no knowledge about color management, printing, and pre-press. Good on you that you care and want to learn!
Keep on asking if you wish.

Is the Illustrator SDK thread-safe?

After searching this forum and the Illustrator SDK documentation, I can't find any references to a discussion about threading issues using the Illustrator C++ SDK. There is only a reference in some header files as to whether menu text is threaded, without any explanation.
I take this to mean that probably the Illustrator SDK is not "thread-safe" (i.e., it is not safe to make API calls from arbitrary threads; you should only call the API from the thread that calls into your plug-in). Does anyone know this to be the case, or not?
If it is the case, the normal way I'd write a plug-in to respond to requests from other applications for drawing services would be through a mutex-protected queue. In other words, when Illustrator calls the plug-in at application startup time, the plug-in could set up a mutually exclusive lock (a mutex), start a thread that could respond to requests from other applications, and request periodic idle processing time from the application. When such a request arrived from another application at an arbitrary time, the thread could respond by locking the queue, adding a request to the queue for drawing services in some format that the plug-in would define, and unlocking the queue. The next time the application called the plugin with an idle event, the queue could be locked, pulled from, and unlocked. Whatever request had been pulled could then be serviced with Illustrator API calls. Does anyone know whether that is a workable strategy for Illustrator?
I assume it probably is, because that seems to be the way the ScriptingSupport.aip plug-in works. I did a simple test with three instances of a Visual Basic generated EXE file. All three were able to make overlapping requests to Illustrator, and each request was worked upon in turn, with intermediate results from each request arriving in turn. This was a simple test to add some "Hello, World" text and export some jpegs,
repeatedly.
Any advice would be greatly appreciated!
Glenn Picher
Dirigo Multimedia, Inc.
[email protected]

Zac Lam wrote:
The Memory Suite does pull from a specific memory pool that is set based on the user-specified Memory settings in the Preferences. If you use standard OS calls, then you could end up allocating memory beyond the user-specified settings, whereas using the Memory Suite will help you stick to the Memory settings in the Preferences.
When you get back NULL when allocating memory, are you hitting the upper boundaries of your memory usage? Are you getting any error code returned from the function calls themselves?
I am not hitting the upper memory bounds - I have several customers that have 10's of Gb free.
There is no error return code from the ->NewPtr() call.
     PrMemoryPtr (*NewPtr)(csSDK_uint32 byteCount);
A NULL pointer is how you detect a problem.
Note that changing the size of the ->ReserveMemory() doesn't seem to make any difference as to whether you'll get a memory ptr or NULL back.
btw my NewPtr size is either
     W x H x sizeof(PrPixelFormat_YUVA4444_32f)
     W x H x sizeof(PrPixelFormat_YUVA4444_8u)
and happens concurrently on #cpu's threads (eg 16 to 32 instances at once is pretty common).
The more processing power that the nVidia card has seems to make it fall over faster.
eg I don't see it at all on a GTS 250 but do on a GTX 480, Quadro 4000 & 5000 and GTX 660
I think there is a threading issue and an issue with the Memory Suite's pool and how it interacts with the CUDA memory pool. - note that CUDA sets RESERVED (aka locked) memory which can easily cause a fragmenting problem if you're not using the OS memory handler.

Visual c++ express - Illustrator SDK

Hi,
does anybody know if it´s possible to use the "Express Edition" for Illustrator coding
or are there limitations with it. What do you use for coding - srictly Visual Studio/ Code Warrior? Are there any other resources/examples on the net, book or whatever besides the ones that come with the sdk. Any suggestions on how to start coding Illustrator are welcome - come on pros, please share same knowledge ;)
Cheers Pat

Visual Studio Express should work. Contact me for more specific information. Some Visual Studio 6 projects, and much portable plugin source code, is available from
my site.
In fact nearly all of the free Windows development systems will work, including
Borland CBuilder,
OpenWatcom, and probably
Digital Mars and
lcc-win32. I use
MinGW (a complete GNU-based Win32 development system) frequently to build Illustrator and Photoshop plugins.

Hi, cannot convert RGB to CMYK...

I cannot find such an option in the Elements? Can anyone help how can I convert the files to CMYK from RGB using this tool...
Thanks
ansu

Elements can't convert RGB to CMYK. You'd need the full Photoshop.
Otherwise you can google 'RGB to CMYK' conversion to find online or software tools that can do that.
The real question is why do you need CMYK. If it's a request from a printer shop, it's their job and responsibility to do the conversion, since such a conversion can only be properly done when you know the specificity of your printing tools, inks and papers.

Converting RGB to CMYK color

Hi All,
I have few BASIC Questions on converting RGB to CMYK in Photoshop and Illustrator. Hope could get some professional insights here.
1, Are all the DTG printers set only in CMYK color mode ?
2, If there is no difference after viewing RGB image with 'Gamaut Warning' (Photoshop), Does that mean I'll have the exact print result as monitor view ?
and Basically no need for CMYK conversion ?
3, Please list some the most effective way to convert RGB to CMYK, and keep the final CMYK color result as close as the RGB.
4, when I simply convert one RGB image to CMYK color, why Ps/AI don't allow me to save as PNG file ?
( I save the file as PDF, but I cannot edit this PDF using apple preview app )
5, compare Photoshop to Illustrator, which one result better final CMYK color image ?

Thanks for the detailed reply. Sure clear some of the doubts.
I just start to draw/design in Photoshop and illustrator, I save my files most as PNG, for a transparent background.
After I went to officework do the poster printing, I found the color of my print image are not as vivid as Mac preview.
To be precise, the poster I printed looks like has a very thin grey layer, it is not much noticeable, but it indeed lost some vivid color. As I want to print out my works and keep color as close exact as Mac preview, here is the issue of coverting RGB CMYK.
Please feel free to add for below:
1, Should I set color space in CMYK before drawing in PS/AI
2, in PS, I convert profile from PNG file to CMYK save as psd file, that psd file preview exactly same as PNG.
But when saved as PDF, the file preview a bit grey. Can someone explain this?
3, Now im thinking, since CMYK is all about printers, it really should be the profession in printing shop who shall check my image, and edit/convert to the right color space to fit their printers.

Can i create program, using Adobe Illustrator SDK, which would understand *.ai file format (cs versi

I need to write converter from cs ai files to my own format.
Can i use Adobe Illustrator SDK for creating such a program?
Is there in SDK libraries, which would be used for reading by program cs ai file format?
Must Adobe Illustrator be installed for such a program would work?

Well, if Idraw can do it you would need to figure out which format it likes (probably tiff would be my guess), save in that format and open the image there and proceed with however it works. The only useful advice I can offer is that jpg is a poor choice for any image that includes text. It will be fuzzy.

Convert RBG to CMYK in photoshop elements 7...

Convert RBG to CMYK in Photoshop elements 7.....could not find how to do this in help...thanks

Sorry, but this is one of the very hard lines that Adobe draws between PS and PSE. You simply can't do it in PSE, because they want you to buy PS for that.

Having troubles converting RGB to CMYK

@Hi guys
I having massive issues with converting my business logo form RGB to CMYK. I need to place this logo on my business card ready for printing. I created the logo in RGB format to start of with, but it keeps coming out darker and abit grayscaled
once the conversation is set. Can anyone help me out with this issue, and if so, can you also provide the steps in how to resolve this issue for future references. Im using Adobe Photoshop CS5 for this execise. I can also provide the actual image attached below as the second image,.

These bright pink and purple colours are obviously way out of gamut so they convert badly to CMYK. Exactly how they convert depends on what colour profile you are using
It will probably be best to either rework the design using mixtures of cyan and magenta only or else use mixtures of Pantone colours.
The Pantone solution will only work for offset printing but is no use for a home printer.
Read up on colour management like Mylenium says and learn to think in terms of inks rather than screen colours.

Persistent "Converting colors to CMYK" progress bar

There is a file I've been working on for a couple of weeks that I am all of a sudden having issues opening. I applied some effects to a photo within the document, and ever since then the program has been freezing up or having issues opening the file. It keeps on cycling through dozens of progress windows that say "Converting colors to CMYK". The progress bar loads in about 10 seconds before another one, exactly the same as the last, shows up. I've sat there and watched it cycle through like this for over 30 minutes on multiple occasions in the last 24 hours, just trying to be patient and see if it will ever load.
I have tried rebooting the computer, restarting the program, and downloading the latest updates. Nothing has made a difference. The file size is 26.6 MB with around 20 photos in it, and my computer isn't the fastest in the world, but this shouldn't take forever. Does anyone have any advice on this?
Thanks,
Zac
2010 MacBook Pro 13"
2.4 GHz Intel Core 2 Duo
8 GB 1067 MHz DDR3
NVIDIA GeForce 320M 256 MB

I don't know if this will work but try setting the scratch disk for Illustrator to the Seagate instead of the internal HD and see if you have better luck. With less than 20% of the HD available it is starting to become a problem. Have you ever resaved the file with a Save As and overwritten the original? If you have been changing the images without doing this there is likely a lot of old previews and such held in the hidden part of the file which will be cleared by doing this.

Illustrator SDK converts LAB to CMYK, how to avoid?

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