CMYK to RGB to CMYK again...why?

I'll be the first to admit - I am relatively new and inexperienced when it comes to color management.
I am a prepress tech - 6 years now or so. Been in printing for 24 years - was a conventional stripper before that.
Not a complete dummy but I was never exposed to the old ways of electronic prepress -
My question is a "why?"
We have a PDF based workflow running Trueflow.
Because we have an older version of Trueflow that requires specific settings in order to accept PDF files, I have a certain criteria that supplied PDFs must meet.
I don't always get them that way - so I have a preflight routine where I open all PDFs and check them for spots/RGB/Lab color swatches, etc and convert as needed to CMYK. I then flatten them in PitStop extreme and run them through my rip.
We do not have the ability to proof with ripped PDF files - therefore, when a PDF proof is required, I want it to be the print file that will be used to output to plates.
OK - now you have a little background about my methods -
Here is the question.
My client was supplied a CMYK vector PDF ad.
Artist for the client opened ad in photoshop, rasterized it and converted it to RGB, placed it in his Quark document and sent the 16 page PDF file to me
I received it, noted that the file was full of spots and RGB and did a conversion back to CMYK in pitstop
We sent a PDF proof to the client, who approved it (for the record, when we PDF proof, we assume that color is not critical otherwise the client would have asked for a matchprint)
OK - so we print the booklet and client is very unhappy with the color on the back page.
Artist says that we should have let the rip convert the RGB file to CMYK instead of doing it myself - like I trust my rip to do what it should - I don't - it has made a mess of things in the past. I know what condition my files have to be in before they go in the oven. I don't take chances.
My question is, why would he convert it to RGB in the first place? I am completely lost on this one. If I am supplied a CMYK file, what reason is there for converting it to RGB before placing it into the document?
Can anyone explain why this would be necessary?
Thanks in advance!!!! I'm sure there are some gurus out there who can make sense of it in explaining it to me.

From what you describe in the original post, I get the feeling that the wrong question is being asked. In the particular case, there was probably no need at all to convert (or maybe even rasterize) the PDF you supplied. If the client's artist only needed to make minor changes to an existing layout, he or she would obviously have been better off applying those changes to the original layout document (InDesign, QuarkXPress) to conserve editable vector data and the source colours of any pixel images. Only if the original layout document was not available or had been modified colour-wise at a later production stage would I have used a PDF as the basis for editing the ad. Maybe the artist inadvertently made the RGB conversion when rasterizing the PDF? As you supplied the PDF and your company ultimately did the printing as well, I see no reason why the data would have to be converted to RGB and back to CMYK; the artist could have easily left everything as is and just added the modifications. What flavour of PDF did you supply? For your CMYK safe workflow, I guess PDF/X-1a would have been the most appropriate one*. Then the artist could work in the device space as you do or convert any new RGB content to the CMYK space as specified in the PDF/X output intent. I would recommend to communicate who does what before the layout work rather than after printing and running across unpleasant surprises. Redundantly converting colours back and forth without a clear and strict process and colour management is a very bad idea in my opinion, and as you saw, it can yield quite unsatisfactory results. It does take more effort to set things up properly, but in the end it tends to cost less and deliver (far) better results than troubleshooting and re-printing a screwed-up mess.
* If your Trueflow system requires different, non-standard PDF settings, then things get more complicated. Your company's management may want to consider whether the equipment on hand is really up to the tasks it is supposed to perform ...

Similar Messages

Why does Illustrator automatically change RGB and CMYK values

Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
Very confusing.
Thanks in advance if you can explain this behavior!
Best Regards,
Z.

Color management.
Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
An Ai document can be either RGB or CMYK. The colors follow the document color mode and thus are converted immediately if they don't match.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
Same reason.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
It's not. CMYK color spaces (there are more than just one) are normally smaller than RGB color spaces, but they aren't a "subset".
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
When Illustrator converts the colors, it uses color management: the profiles you set up and the methods you set up. After converting it forgets the color that used to be. When converting "back", it uses color management again.
When you convert an very bright RGB color, it be out of the CMYK gamut. So it get's converted to the closest possbile CMYK color (which might still be far away from the original color. But it's not possible to convert it "back" to the bright one unless you just revert the conversion (by Cmd/Ctrl + Z).

Why do Adobe Color CC and Indesign CC not convert CMYK to RGB the same?

I recently used Adobe Color CC to create a color theme that will be used for both print and web. I created the theme with approved CMYK values with the intent of saving the .ASE file to be imported into other CC apps. Corresponding RGB, Hex, Lab and HSB values are automatically created. Of course, we are using CMYK for print and RGB for web
A coworker had separately created the same exact CMYK theme in InDesign CC, and created RGB values from the same exact CMYK values I had used in Adobe Color.
The InDesign RGB values are quite different from the Adobe Color values.
Anyone know why the values are not the same, and moreover, which CMYK to RGB conversion values may be relied upon for accuracy?
EDIT: I guess the real question should be, What are the color management settings built-in to Adobe Color CC, and can they be duplicated in desktop Adobe CC applications?
Thanks very much

I found what change it to normal way, but logicaly it's should not be a reason for autoconvert colors. If I choose CMYK and want add CMYK color it should be CMYK (in name minimum) and not RGB.
File->Documents Colors->CMYK(should be, but RGB was)
Right now options open like CMYK, not HSB. But if I want color in RGB it added like CMYK. Options like in CMYK, not HSB, again. Still look like error.

Why Illustrator CS6 convert CMYK to RGB when I do "Add to switches" in Color menu?

1. Open Color menu and work with color in CMYK.
2. Do "Add to switches" (or "Создать новый образец" in Russian)
3. See that new color was added like RGB not like CMYK.
4. When I open parameters it show me HSB options.
5. I switch it to CMYK and push OK
6. Nothing cange - RGB in name and HSB in options.
Look like it's error.

I found what change it to normal way, but logicaly it's should not be a reason for autoconvert colors. If I choose CMYK and want add CMYK color it should be CMYK (in name minimum) and not RGB.
File->Documents Colors->CMYK(should be, but RGB was)
Right now options open like CMYK, not HSB. But if I want color in RGB it added like CMYK. Options like in CMYK, not HSB, again. Still look like error.

Why do the relative values of RGB and CMYK change when switching between Photoshop and InDesign?

I'm trying to put together a Colour Guide for my company's brand guidelines.
I initially worked from InDesign and wrote down all the H, RGB, and CMYK values that I got when I eye-dropped my original colour palette.
However when I put the same RGB values into Photoshop- I am given a (slightly) different set of CMYK numbers from those that I had originally documented in InDesign.
Why is this???

Jamie,
in Photoshop go to Edit > Color Settings and choose your parameters:
For RGB: sRGB or AdobeRGB (1998)
For CMYK: the process as recommended by your printer (person, company)
For offset printing this is here ISOCoated-v2-eci and elsewhere for instance SWOP.
For digital printing you should ask the company as well.
For Grayscale: Gray Gamma 2.2
For Spot: probably irrelevant in the moment. Dot Gain 20%
Everything as shown here:
For your application I've modified my settings a little, therefore we can see top left 'unsynchronized'.
In InDesign do practically the same, but there are no settings for Grayscale.
You'll find for any topic explanations if you move to by mouse (position the pointer over ...).
The field 'Settings' shows not 'Custom' but the file name of a configuration which had been previously saved
and then loaded (buttons top right).
Further explanations on request. It would be quite useless to explain everything now at the same time.
The colors will be wrong if the settings are not synchronized. Above they are explicitly synchronized.
Because Bridge was not used, the system considers them as 'not synchronized', which doesn't matter.
Best regards --Gernot Hoffmann

Why don't Adobe Color CC and InDesign CC convert CMYK to RGB the same?

I recently used Adobe Color CC to create a color theme that will be used for both print and web. I created the theme with approved CMYK values with the intent of saving the .ASE file to be imported into other CC apps. Corresponding RGB, Hex, Lab and HSB values are automatically created. Of course, we are using CMYK for print and RGB for web
A coworker had separately created the same exact CMYK theme in InDesign CC, and created RGB values from the same exact CMYK values I had used in Adobe Color.
The InDesign RGB values are quite different from the Adobe Color values.
Anyone know why the values are not the same, and moreover, which CMYK to RGB conversion values may be relied upon for accuracy?
Thanks very much

It's working for me (Web, PS, AE, ID, FL; not available in the Color Themes panel in Ai). Please click the triangle next to the color space to expand and view more data.

Once again: RGB to CMYK using Acrobat?

I received a lot of photographs in RGB (my color space for RGB is default to preserves embedded profiles) and make a proof in IDCS4:
1) I converted that batch to CMYK using PDFX-1a/2001
2) I converted to CMYK in Photoshop and later distilled
And the result is different. More darker photographs were obtained with the first step. Blacks were different.
How to avoid the previous conversion in Photoshop and obtain better results (or those obtained in step 2) directly with Acrobat?

mariana pineda wrote:
I received a lot of photographs in RGB (my color space for RGB is default to preserves embedded profiles) and make a proof in IDCS4:
1) I converted that batch to CMYK using PDFX-1a/2001
2) I converted to CMYK in Photoshop and later distilled
I'm a little confused here. With 1, you placed all RGB into InDesign, then exported PDF/X-1a from InDesign. With 2, you converted in Photoshop, placed in InDesign, output post script and distilled. Is that correct?
Neither one involved an Acrobat color conversion. 1, the conversion is done by InDesign. 2, the conversion is done in Photoshop.
Ideally, 1 is the best option. Place all RGB images into InDesign. Output PDF/X-1a, you end up with a CMYK PDF.
To ensure you achieve the same conversion that way that you would have in Photoshop, first go to Edit: Color Settings in Photoshop. Make sure Preserve Embedded profiles is on, and note the CMYK working space. The behavior should be (if you were to do the conversion in Photoshop): open the RGB, preserving the embedded profile. Mode: CMYK will move the image to your working CMYK color space.
Now go to InDesign. Open the document in question. Edit: Assign profiles, and note the RGB and CMYK. Make sure the CMYK matches what you saw in Photoshop.
Now go to the Links panel. Check the ICC profiles for the placed RGB. None of them should say Document RGB, let me know if they do.
Now when you export PDF/X-1a, in the destination color select Document CMYK. The conversion should match what you would get in Photoshop.

RGB or CMYK colour formatting for iPhoto Albums printing.

Hi.
I'm putting my first iPhoto Album together. Info given from Apple about what colour format to use for your photos, says to use RGB. While this is corrcet for digital monitors and screens. Mass printing uses CMYK. Any images supplied to a printers in RGB will colour shift when printed in CMYK. No matter what a printer tells you, these colour shifts can be very noticable. I'm an Advertsing Art Director and I've seen the shift that happens.
I will be checking/colour correting all photos submitted to the iPhoto Album with Adobe Photoshop. And many will very probably undergo some corrections. Be it through levels, curves, hue/saturation, etc. Nothing to anything near an excessive level, but enough to make obvious improvements.
So I will then be faced with the choice of whether to save the images out in RGB or CMYK.
Can someone with some technique knowledge, from the iPhoto team, tell me/reasure me why RGB has been specified? And if CMYK wouldn't actually be a preferable colour format to supply in, considering you'll be printing them in CMYK.
Many Thanks, Jim.

You're absolutely correct. I was referring to notes make a number of years ago in regards to iPhoto 5 and that RGB was recommended for both books and prints.
I was confusing CMYK with Grayscale with Dot Gain 20% profile when stating iPhoto didn't support it which it didn't fully support until iPhoto 9.
In fact I just ran a test with iPhoto 6, 7 and 8 with a CMYK AND GrayScale files with the following results:
iPhoto 6 (06): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 7 (08): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 8 (09): neither file would import which is surprising:
iPhoto 9.2.3 (11): both imported and viewed normally.
iPhoto 9.4 (11): both imported and viewed normally.
In Oct, 2007 I got an email from Apple support with the following:
Also as iphoto makes a pdf of the book and then uploads it to keep the size down, it doesn't matter if the pics are RGB or CMYK as a pdf is a closed file. But since it is going through prinergy it has an RGB checker so this most be switched off. It is how the software in prinergy handle's it that causes the washed out affect as it takes the Red Green Blue colours and tries to convert to Cyan Magenta Yellow Black. Now the colour spectrum in printing between rgb and cmyk is quite different looking at a colour wheel will show you. The best way i can describe it is if you have a pantone book which has spot on one side and process on the other you can see a colour difference. Or if you use quark open up the colours and again switch between process and spot.
BUT ONLY CONVERT PICS TO CMYK IF YOU ONLY INTEND TO ORDER BOOKS. IF YOU INTEND TO ORDER PRINTS IT WILL NEED TO BE RGB.
Here's how i see it:
1. Apple doesn't want 2 different versions of the pics floating about as running CMYK through a photomachine (as prints you would order in the high street) will not print correctly.
2. RGb's going through a CMYK press using prinergy will attempt to convert and produce the washed out effect, or yellowing effect BUT will still print.
So it will use the 2nd option as it will still produce prints normally and books with a slightly washed out effect. Now to most people in the high street, who will notice a difference?
I have just received my latest book saved as CMYK pics in tiff format and no washed out effect. What i will say is The quality if still not as good as a print. Now we use a docucolour 5252 at work and the colour quality is better. I wonder how often the machine is calibrated and what colour curve it is set to?
However, I am unable to import a CMYK file in any iPhoto version until iPhoto 9. Go figure.
Thanks for the feedback. Hadn't addressed this particular subject in quite a long time.

Converting to .jpg to print (RGB vs.CMYK)

Hi all,
I am fairly new to adobe and all things it has to offer. I am slowly learning how to do everything myself. I am currently using CS6. I made myself a 16x20" poster in Illustrator, converted it to a .jpg using the export menu. I put it to my flash drive and printed it out at a local fed ex office. When converting it to jpg, I kept it in CMYK color mode, and set it to be at the highest resolution and the highest quality file I could have.
Now, I made another poster for a friend and did the exact same thing. Instead of taking her .jpg somewhere to get printed, she is trying to upload it to a photo printing site (walmart, snapfish, shutterfly) to get it printed and mailed to her. Her poster keeps getting errors on the photo uploading site saying it is corrupted and not a valid file type. I was confused, so I tried messing around with the illustrator file a bit, I ended up changing the color mode to RGB when I converted it to a jpg (I still made the artwork in CMYK mode). This uploaded fine to all the photo sharing sites, and was also half the size of the original .jpg (12 MB vs. 24). So then I googled it, and came across a website that says printers only print in CMYK. So if that is the case, what will happen when she prints this poster? And why won't these photo uploading sites allow me to upload a poster that is in CMYK mode? If printers only print in CMYK, you would think it wouldn't be a problem.
On a side note, when I try to upload the CMYK .jpg image to Fed Ex office online, it perfectly uploads. So maybe this is just a problem with simple photo uploading sites?
Thanks for the help! Again, I am fairly new to illustrator so I don't understand color modes much or much else.

I suggest you get your hands on Adobe's Print Publishing Guide. I am sure there are many online "photo" print services out there. The key is they are "photographic" printers which are RGB based. It wouldn't surprise me if they incorprated some type of default rejection coordinance where they reject CMYK files. You should be looking at PDF instead of JPEG anyway. And, since that is a large format print job, a medium resolution based PDF is adequate and small enough to send FTP. The advantage to PDF is it can honor a well established color workflow. Focus on reading the various RGB color spaces and the different levels of PDF. Also, spend some time on color management and converting from RGB to CMYK. I'd be interested in learning which color settings and workspace profiles you have in place.

How do I find out if a photo in iPhoto is RGB or CMYK color? How do I change from RGB to CMYK?

How do I find out if a photo in iPhoto is RGB or CMYK color? How do I change from RGB to CMYK?

Open the file with Preview, type Command + i to bring up the Info pane and it's color mode and profile will be listed as shown here:
To change the color mode to CMYK you'll need a 3rd party image editor like Photoshotp or GraphicConverter to do it. Why do you need CMYK?
OT

CMYK and RGB Issues between PS and AI

I also posted this in the AI forum, not sure if people look at both. If this is taboo, sorry.
Greetings
I am using AI and PS CS5.
I have an eps in AI that is set for RGB. The colors are how I want them.
When I open the same eps in PS, PS thinks the file is CMYK. Whether I open the file as CMYK and convert to RGB or open at RGB, the colors shift. If I leave the file as CMYK, the colors are shifted.
I can confirm that when I convert the file in AI from RGB to CMYK, I can see the color shift. If I leave the file as RGB in AI, it looks how I want.
I cannot get the file to show in PS as the same color as what I see in AI.
I have confirmed that both AI and PS have color settings set to NA GP2.
I am hoping this is something simple and someone can help me out.
I hope this helps explain:
http://img170.imagevenue.com/img.php?image=576032284_colorshift_122_52 4lo.jpg
Basically, the file with AI in RGB mode looks how I want. The file with AI in CMYK mode looks different.
In PS, both RGB and CMYK color mode are the same as CMYK in AI.
I am not sure why PS does not show the RGB colors like AI does.
PS CS5 and AI CS5 are synched:
http://img157.imagevenue.com/img.php?image=586919644_colorsync_122_199 lo.jpg
I think this is a PS issue? Thanks in advance.

File -> Document Color Mode -> RGB is the default when the EPS is opened in AI. This displays what I want.
When the EPS is opened in PS, the default is CMYK. Whether I change it to RGB there or import as CMYK and then change the mode to RGB, the colors do not change. In PS, they look like what I see when in AI when the EPS is set to CMYK, if do this: File -> Document Color Mode -> CMYK.
So in PS, whether I have mode set to RGB or CMYK, it looks the same.
And in AI, based on the setting Document Color Mode, I can see the difference.
How do I get what I see in AI in RGB mode to appear in the same EPS in PS?
Thanks

RGB to CMYK (channels) with PixelConduit plugin

As I'm unable to submit a user tip yet, I thought I'd share my solution here for anyone looking to simulate CMYK channels in Motion/FCPX.
PROBLEM
For some reason you want to convert your RGB source clip to extract individual CMYK (Cyan, Mangenta, Yellow, blacK) channels. For example you'd want to simulate the printing process of a book on a printing press.
SOLUTION
Use a free FCPX/Motion 5 plugin caled PixelConduit, a node-based visual effects design system. Install the plugin before launching Motion.
To extract CMYK channels, I used a (linear) RGB to CMYK formula:
Black   = Math.min( 1 - Red, 1 - Green, 1 - Blue )
Cyan    = ( ( 1 - Red )   - Black ) / ( 1 - Black )
Magenta = ( ( 1 - Green ) - Black ) / ( 1 - Black )
Yellow = ( ( 1 - Blue ) - Black ) / ( 1 - Black )
and translated it to PixelConduit's nodes.
Clone your source clip four times. Call the clones 'Cyan', 'Magenta', 'Yellow' and 'Black'. Navigate to Library > Filters > Conduit Effect System, choose Conduit and apply it to each clone layer. In Inspector, click 'Show Conduit Editor' and assemble the following node tree for each layer:
K (black) layer:
C (cyan), M (magenta) and Y (yellow) layers are identical except the first channel selection:
So, for M and Y layers change the 'Separate RGBA' node to output the green and blue channel respectively. You can copy/paste the whole node tree between intances of the filter so you don't have to create everything again from scratch.
You should now have four layers outputting a simulation of C, M, Y and K channel in greyscale. If you'd like to present these channels in colour you'd need to add Colorize filter to each clone layer:
And finally, if you use Multiply Blend Mode for each clone layer group you'll get a pretty close colour composition to the original source clip! By fine-tuning colour values in Colorize filters and/or tone curves in Conduit you could probably get a perfect conversion.
Colour values used in Colorize filter:
Remap White To:
1, 1, 1 (all)
Remap Black To:
0, 0.61, 0.89 (cyan)
1, 0, 0.5 (magenta)
1, 0.95, 0 (yellow)
0, 0, 0 (black)
That's it! Hope it can help anyone :^)

As I'm unable to submit a user tip yet, I thought I'd share my solution here for anyone looking to simulate CMYK channels in Motion/FCPX.
PROBLEM
For some reason you want to convert your RGB source clip to extract individual CMYK (Cyan, Mangenta, Yellow, blacK) channels. For example you'd want to simulate the printing process of a book on a printing press.
SOLUTION
Use a free FCPX/Motion 5 plugin caled PixelConduit, a node-based visual effects design system. Install the plugin before launching Motion.
To extract CMYK channels, I used a (linear) RGB to CMYK formula:
Black   = Math.min( 1 - Red, 1 - Green, 1 - Blue )
Cyan    = ( ( 1 - Red )   - Black ) / ( 1 - Black )
Magenta = ( ( 1 - Green ) - Black ) / ( 1 - Black )
Yellow = ( ( 1 - Blue ) - Black ) / ( 1 - Black )
and translated it to PixelConduit's nodes.
Clone your source clip four times. Call the clones 'Cyan', 'Magenta', 'Yellow' and 'Black'. Navigate to Library > Filters > Conduit Effect System, choose Conduit and apply it to each clone layer. In Inspector, click 'Show Conduit Editor' and assemble the following node tree for each layer:
K (black) layer:
C (cyan), M (magenta) and Y (yellow) layers are identical except the first channel selection:
So, for M and Y layers change the 'Separate RGBA' node to output the green and blue channel respectively. You can copy/paste the whole node tree between intances of the filter so you don't have to create everything again from scratch.
You should now have four layers outputting a simulation of C, M, Y and K channel in greyscale. If you'd like to present these channels in colour you'd need to add Colorize filter to each clone layer:
And finally, if you use Multiply Blend Mode for each clone layer group you'll get a pretty close colour composition to the original source clip! By fine-tuning colour values in Colorize filters and/or tone curves in Conduit you could probably get a perfect conversion.
Colour values used in Colorize filter:
Remap White To:
1, 1, 1 (all)
Remap Black To:
0, 0.61, 0.89 (cyan)
1, 0, 0.5 (magenta)
1, 0.95, 0 (yellow)
0, 0, 0 (black)
That's it! Hope it can help anyone :^)

Cannot completely convert PDF from CMYK to RGB

I have a 48-page CMYK pdf that was produced by Quark. All placed images are CMYK.
Using Acrobat X, I select Tools -> Convert Colors -> Convert Colors to Output Intent sRGB IEC61966-2.1, I am able to convert 99.99% of the document to RGB. However, a tiny portion of the document (a total of only 32 pixels) stubbornly remains CMYK. I cannot get a completely RGB PDF, and it's causing problems with our production process.
The parts that remain CMYK are miniscule. For example, there's an apostrophe on page 34, the top half of a comma on page 8. Examination of the uncompressed PDF reveals 3 tiny CMYK objects. Here's a typical object that is only 3x6 pixels.
5606 0 obj
<<
/ColorSpace /DeviceCMYK
/Subtype /Image
/Length 6
/Width 3
/Type /XObject
/BitsPerComponent 1
/Height 3
>>
stream
^Q^P^Q^P^Q^P
endstream
endobj
Also, at one point in the document is a reference to a /Separation of DeviceCMYK, which I don't understand (I assume this is item (1) in the report below:
3307 0 obj [/Separation /All /DeviceCMYK 4249 0 R]
endobj
When I produce a preflight inventory, it reveals four references to CMYK:
(1) Color Space 316 (out of 316)
on page 45
Color Space properties:
Separation color space: "Registration color" CMYK (1.0/1.0/1.0/1.0)
Color name: All
Alternate color space
DeviceCMYK color space
(2) Image 935 (out of 2432)
on page 48
Image properties:
Page 48: CMYK
Width/Height (pixel): 3/3
Bits per color component: 1
Treated as a mask: False
Perform interpolation: False
Compression/encoding
ZIP/Flate compression (FlateDecode)
DeviceCMYK color space
(3) Image 2233 (out of 2432)
on page 34
Image properties:
Page 34: CMYK
Width/Height (pixel): 2/5
Bits per color component: 1
Treated as a mask: False
Perform interpolation: False
Compression/encoding
ZIP/Flate compression (FlateDecode)
DeviceCMYK color space
(4) Image 2302 (out of 2432)
on page 8
Image properties:
Page 8: CMYK
Width/Height (pixel): 2/7
Bits per color component: 1
Treated as a mask: False
Perform interpolation: False
Compression/encoding
ZIP/Flate compression (FlateDecode)
Why can I not complete the CMYK->RGB conversion? And why do only 32 pixels out of millions in the document refuse to convert?
Is there a way to force the document colorspace and all colors to become RGB beyond what I've already done?

That might be it, Jacob.
It's when, for instance, I have the Appearance window open and shift-click on the stroke or fill to see the color attibutes (rather than simply looking at the swatches). It kept showing up in CMYK.
But making that change in the flyout seems to have it showing properly.
Thanks!

Auto rgb to cmyk

when i open a file in photoshop cs5 i want it to be automatically converted from rgb to cmyk with me having to kick off any action. I had this setup on my previous puter. Pls help.

Maybe you had an Action or Script and triggered it with the open event in
File > Scripts > Script Events Manager
But why do you convert the images to CMYK anyway?
And are you certain the particular CMYK space meets all subsequent needs?

CMYK to RGB conversion in photoshop

Hi,
I have synchronized my colour settings in bridge to be the same across all my Adobe software, it's currently on Europe Prepress 3 because that's what I've been taught is correct in Australia. I have a colour swatch of C:0 M:90 Y:15 K:0 and when I change the colour slider to RGB in photoshop is gives me the values: R:200 G:53 B:122 (not sure if this is a good way of converting the colours?)
My initial swatch:
When I key this exact RGB value online it gives me a much darker swatch:
So using multiple cmyk to rgb online converters (to compare) I key in my initial cmyk values and the rgb swatch it converts to is so much brighter and gives me the values R: 255 G:25 B:217
I know I'm doing something wrong. I hope someone can help me with this!
Thanks in advance!

This is about 1) different color spaces which will have different numbers for the same color, and 2) gamut limitations going from one space to another (some color spaces are bigger than others and can contain more saturated colors).
"Europe Prepress 3" is just a preset. It sets Adobe RGB as working RGB, and FOGRA39 as working CMYK. When you go online, however, you'll most likely get numbers corresponding to sRGB and US Web Coated (SWOP) v2, because these are the Photoshop defaults (but have no particular significance beyond that). IOW there are no such things as "RGB" and "CMYK" - only specific RGB color spaces and specific CMYK color spaces.
In different color spaces, such as sRGB vs. Adobe RGB, the same color is represented by different values. That's why you have to convert from one to the other.

CMYK to RGB to CMYK again...why?

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