Blending modes, RGB to CMYK

Hi,
Is there any way that blending modes in cmyk look the same (change the colors in a same way) as that they are in RGB ?
Thanks

Is there any way that blending modes in cmyk look the same (change the colors in a same way) as that they are in RGB ?
No. Not only because of what CC already mentioned, but because CMYK has a different gamut and belnding logic behind it to begin with. There simply is no way to e.g. accumulate additive blends in the way RGB mode does, because you couldn't print it like that, anyways...
Mylenium

Similar Messages

How to change the document color mode(RGB to CMYK)?

Kindly advice me how to change the document color mode(RGB to CMYK) via scripting in "illustrator cs3".
Thanks.

Somebody wrote and posted this a couple of years ago.
// Duplicate the selection from the active document into a new document.
// To invoke the JavaScript debugger, remove comment delimiters
//$.level = 1; debugger;
var newItem;
var docSelected = app.activeDocument.selection;
if ( docSelected.length > 0 ) {
// Create a new document and move the selected items to it.
var newDoc = app.documents.add();
if ( docSelected.length > 0 ) {
for ( i = 0; i < docSelected.length; i++ ) {
docSelected[i].selected = false;
newItem = docSelected[i].duplicate( newDoc,
ElementPlacement.PLACEATEND );
else {
docSelected.selected = false;
newItem = docSelected.parent.duplicate( newDoc,
ElementPlacement.PLACEATEND );
else {
alert( "Please select one or more art objects" );
It should give some ideas about how to proceed.

Colour mode rgb to cmyk

hello forumers.
id like to know if i download an image from the web which is rgb,can i convert the image to cmyk for no one to notice it was initialy taken from the net?
the reason im asking is because my teacher told us not to take any image from the net,(so we take photographs our selves).and if we do take an image from the net,he will know just by looking at it.
is this true?how can i convert if possible tell me please.
thank you.

I agree with Chris, and others - a good assignment should have several elements to it, and learning each, is what one should strive for.
A lesson might seem simple, like RGB Color Mode to CMYK Color Mode, but will likely have additional aspects, like dealing with a commercial printer, and working with their specified attributes for CMYK.
Same could be said for a lesson on isolating elements in an Image. One could buy a stock Image, with an Alpha Channel, but that would bypass learning how to create that Alpha Channel, and in life, not all Images come with Alpha Channels, or at least the one(s), that one might need/want.
A good instructor will structure a lesson with many parts, leading to the end result.Learning each part, will improve one's knowledge of Photoshop. I recommend against taking any short-cuts, as when one walks out the door, into the real world, knowing how to do everything in PS, will be very important.
Adobe has a nice series, Classroom in a Book, for many of their products. For most exercises, there is a "finished" version of that exercise, on the included disc. One could just print out the "finished" version, and then proclaim, "Hey, I finished Adobe Classroom in a Book for PS CS5," but what would they have learned, along the way? Almost zero. Learning is open-ended, and should be a goal, and never-ending.
I've been using PS for about 2 decades, and have made very good living with it. However, one of the main reasons that I come here, is to learn more. One can never know it all.
Also, prior to my retirement, I often did not have the leisure to learn new methods, as I had deadlines, so had to just go with what I knew. When I had downtime, I spent those hours in CiaB, or by taking community college courses in Photoshop (and Illustrator, InDesign, Flash and Dreamweaver), though I already had degrees in Civil Engineering and Cinematography, plus many hours toward my MFA. I did not care about any academic credits - only learning.
Do not take the easy way out. Do each exercise/assignment, as structured. If good, they will teach you more, than just the subject of the exercise/assignment. Should be much more to learn, than just one aspect of PS.
Enjoy your classes, and the exercises. The more that you do learn, the more that you can offer your clients, later on.
Good luck,
Hunt

How to work around "screen" blending mode in CMYK document?

The document has been created in CMYK from the start. But I would like to add "glints" over the image and I normally do this by simplyl setting the "glint layer" to "screen" blending mode (when working in RGB color mode). As you all know, this does not yield desirable results when working in CMYK mode. What is the best way to get this type of effect in CMYK mode? Attached are 2 jpegs to help illustrate my point. (Text and logos have been blurred out).
Here is the "glint layer" which I usually just set to "screen mode" to take out the black, but this does not work in CMYK mode.

Okay so here is the same 2 documents again. The document on the right was the one that I tweeked, (the CMYK one). I used the "img, adjustments, brightness/contrast" and I boosted the contrast up to 100% which I feel got me the rest of the way there. This is very close to the RGB effect on the left and I feel that with a tiny bit more tweeking I can get this to work. Thank you all for your help and suggestions. I am going to credit c.pfaffenbichler with the correct answer as his comment was the one that helped me personally the most. Thank you guys for the excellent help.
So once again to clarify the correct answer. Create the doc in CMYK, grab your "glint layer". Adjust the curves and then maximize the contrast and then set the layer to screen.
Thanks again guys!
Cheers,
-Zander

Color converting RGB to CMYK mode???

Is it possible to convert RGB to CMYK color mode in Elements 10?

No, not really. If you google around, Richard Lynch had a sort of workaround for this for very early versions of PSE that could possibly be adapted for current use, but a proper CMYK conversion is much more complex, even with the proper tools, than going from sRGB to Adobe RGB, for example.
If you have a mac you can do a mode conversion in Preview, but you may not like what you get from the print shop using that method.

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 :^)

Blending Modes

Hi All,
I am creating a flyer in InDesign, I've got a logo to put at the bottom of the flyer, the logo is white with a black background, I've used the Screen blend mode to remove the black but I can now see a faint white space behind the logo... see attached image. I have Proof Colours, Overprint Preview & High Quality Display to show the neareat possible match to print.
I've tried Googling and reading up about the Blend modes, it says something about changing the option in Edit > Transparency Blend Space
I changed it to RGB and now the white space has gone but the article I found did not explain too much about what this means changing it and how it works when printing the finished artwork.
Can anyone give me advice on this?
Always appreciated
Regards
James

I've tried Googling and reading up about the Blend modes, it says something about changing the option in Edit > Transparency Blend Space
When you use Screen for the blend mode your black background has to be absolute black for to be completely transparent. If you want to keep your Transparency Blend Space as CMYK and your logo is a CMYK object, the black background has to be absolute CMYK black (100|100|100|100 and not 0|0|0|100):

Formulas for blending modes

Hi,
I want to truly understand layer blending modes so I can use them better and predict their impact. I know from Bruce Fraser's books that the formula for the Multiply Mode is:
result = (top_pixel * bottom_pixel) / 255
This is great for me (I have a BS in Math). The question is: how are the other modes calculated? For instance, i am having trouble figuring out the Color Burn Mode...
Thanks,
Juan Dent

Color burn is a little easier to calculate in CMYK because the numbers are expressed as %
Base % / (1 – Blend %)
For example, bottom layer is 40M. Make a layer above with Color Burn, fill with 50M
.4 / (1 – .5) = .8
The color result is 80M
Because of this relationship, if the base % is half of the blend % the color result matches the blend color:
.25 / (1 – .5) = .5
You could probably arrive at a reliable result using a similar formula in RGB, but the numbers get crunched differently when dealing with 0 - 255
To get multiply in CMYK I always use
(Base % + Blend %) – (Base % x Blend %)
So if bottom layer is 40M. Layer above is multiply, 50M
(.4 + .5) – (.4 x .5) = .7
Perhaps this formula is wrong somehow but it seems to work for me.

Flattening Blend Mode/Layer Effects CS4

Greetings,
Working in PS CS4 Mac 10.6
CMYK document with a simple image layer with Drop Shadow layer effect and blend mode: Overlay.
I can't get the layer to flatten! When I try to flatten, it ends up looking like the original layer without blend mode or drop shadow.
I'm using the method of creating a new empty layer above image layer and merging the two together.
Is this unique to CMYK mode? (I usually work in RGB mode.)
Any suggestions?
Thanks!

an additional layer with a stroke
Are you sure they want a stroke and not a Path?
Hard Light seems to be pretty much the opposite of Overlay, so you could try
• duplicating the background Layer,
• setting it to Hard Light,
• Clipping Masking it so the the Layer in question and
• setting that to Normal –
that should then be able to be merged.
The Drop Shadow however would of course lose its Blending Mode if it is merged to the Layer.

Converting from RGB to CMYK alters shadows

When working with our product photos, I keep them in RGB and add drop shadows to them by drawing rectangular marquees on a separate layer, fill them with black and then apply gaussian and motin blur to them. Works quite well. Plus with the shadow on it's own layer, I can turn it off in InDesign if need be. The problem is when I convert the photo to CMYK for offset printing. It's asks if I want merge the layers to which I say no since I want to be able to turn the shadows off if need be, but when I say no, then the shadows get bigger and do not look as good as they did in RGB. If I say yes to merge, then the shadows look the same as they did in RGB but I lose the ability to turn them off in InDesign.
Is there a way to keep the shadows looking the same when converted to CMYK without having to merge the layers? Using PS CS6 64 bit. Thanks.

gator soup wrote:
... i would think any conversion would be subject to the same anomaly that Photoshop is showing
but i don't know... maybe convert to the destination cmyk before setting any layer effects or adjustment layers
Effects, like gradients, drop shadows, etc are not converted by the color management pixel by pixel because Photoshop doesn't see them as pixels but as a procedure (formula) with key colors for generating the effect in the destination color space. So, for drop shadow, only the shadow color is converted to its closest match in the destination color space but all other parameters affecting the color like the blending mode, opacity, etc are applied in the destination color space which gives different appearance - first, because color space characteristics like gamma curve is different and second in case of a different model (CMYK), the blending of colors is based on entirely different algorithms.
So, basically effects is best to be recreated in the destination color space or flattened before conversion.

Blending mode not looking correct

Hey all. I'm using Photoshop CS6 on a Mac (OS X 10.8.2), and I've run into a wierd problem I've never seen before. I'm creating a seperate layer over a photo, and filling that layer with 50% gray. I then set that layer's blending mode to Overlay. When things are working correctly (and they always have in the past) setting the 50% gray layer to Overlay should render that layer invisible, and it should have no visual effect on the photo underneath. Suddenly this is not the case, and it looks like the grayscale in the photo beneath the gray layer is much brighter. What's really weird is that I tried to recreate this problem on a couple of other pic files, and the Overlay blending mode works fine there! So the problem seems to be only with this one file. Changing the file from CMYK to RGB seems to lessen the effect, but it's still present. I'm sure I'm missing something, but I'm totally stumped. Any help or ideas would be most appreciated. Thanks in advance!

Well, here's a screenshot of my layers pallette, if that's any help. I'd be glad up upload any other setting shot that would help. Thank you.

Convert image from RGB to CMYK and back to RGB

Hey.
I wonder if anyone has experience with converting image from RGB to CMYK and back to RGB?
I had a TIF in RGB then converted to CMYK but I figured that it might be better to keep in RGB, so I converted back. I read that it supposed to cause some loss in the data, but I can't see anything on the image, it is still very huge and the 2 RGB files has the same size as well. Is there a way to compare the resolution of 2 images somehow, or how can I see what I lost through the 2 conversions?
Thanks for help

I had a TIF in RGB then converted to CMYK but I figured that it might be better to keep in RGB, so I converted back.
The original RGB data is not being restored by converting from the CMYK version, so the term "keep" seems inappropriate.
What are the actual Color Spaces (ICC profiles) involved?
Is there a way to compare the resolution of 2 images somehow, or how can I see what I lost through the 2 conversions?
How did resolution come into this?
To determine how large a portion of the image has been changed you could
• make a flattened copy of the original image
• place a flattened copy of the RGB->CMYK->RGB image on top of that and set it to Blend Mode Difference
• add an Adjustment Layer (Curves for example) to brighten the image

RGB to CMYK conversion issue- Pulling my hair out@

Hi there-
I have downloaded a VECTOR image from Shutterstock, and it was built as an RGB file. When I try to convert it to CMYK (File-->Document Mode-->Concert to CMYK), it totally whacks out the image. I have tried everything I know how to do, and can't figure this out. I've tried changing the colors in the palette to CMYK, but it doesn't convert them permanently.
I'm attaching two files (as JPEGS so you can see the problem), one shows the sunshine image nice and smooth. The other is after the conversion to CMYK.
If you have any ideas, or want to see the actual file, please email me at [email protected] and I will send you the actual .eps file.
THANK YOU!
Brent

Original file above.
Select all
Object> Flatten transparency (check preserve alpha transparency with slider to 100 vector)
Change color settings (edit> color settings) to emulate Illustrator 6.
Convert to cmyk mode
Results
There were two main issues converting to cmyk.
Use of screen blending mode and the gradients themselves.
Screen blending mode was described in previous posts.
The gradients look also changed when converting from rgb to cmyk. If the screen blending mode was switched to normal, when converting to cmyk, the gradients would not look the same.
Flattening transparency is not an elegant solution, but it is a quick and dirty one.
Mario described this method in a previous post.
Depending on your color settings, it may yield unwanted artifact colors. Turning off CM, setting to Illustrator 6 emulation, will not yield the artifacts.

Need Info on RGB to CMYK

Hi,
I am new to Illustrator (CS5) and not fully comfortable with RGB vs CMYK. For instance, I created a logo for use on the web using Document Color Mode: RGB where my background color in RGB is 0, 0, 130. When I create a Print document using Document Color Mode: CMYK and copy the logo into the print document, it converts that background color to CMYK (C:100, M:98, Y:16 K:18) where the RGB is now (44, 45, 111).
Is there a way to get a closer match to the original RGB color 0, 0, 130? When the specifications for the print advertisement says images must be in CMYK, I hope I am accomplishing this by using the Print Document Color Mode of CMYK vs RGB? I feel somewhat ignorant on utilizing the RGB vs CMYK color modes and if anyone can give me a tip on what techniques they use to get a closer match of colors for RGB to CMYK or vice versa, I would love to hear it.
Thank you,
Keith

Keith,
First, be aware that you have posted to the Photoshop forum, not the Illustrator forum. The general concepts of color and color management are the same across the spectrum of digital imaging. However, its implementation is slightly different from application to application, so you may also want to post your question to the Illlustrator forum.
[EDIT: Brain fart on my part... This is the color management forum, NOT the Photoshop forum, so you are in the right place! (I spend most of my time in the Photoshop forum; I lost track of where I was...)]
That said, you're running up against a general concept: color gamut.
The color you've spec'd in your RGB file (0/0/130 - and we'll assume for now that it's in the sRGB color space) is outside the gamut of every CMYK color space. That means that the RGB color you see can not be reproduced using a mix of the four CMYK process colors (cyan, magenta, yellow, black). When converting to CMYK, the software picks the closest color that is within the gamut of the CMYK space, hence the color shift.
When you're designing for CMYK, it's best to work in soft-proof mode which allows you to see a pretty close approximation of what your colors will look like in the final color output space - in your case, CMYK.
In Photoshop, to turn on soft-proof, go to View > Proof Setup> Custom... and choose the CMYK output space that matches the press conditions you are designing for.
There are books written about this, but hopefully this short answer points you in the right direction.
Message was edited by: Rick McCleary

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

Blending modes, RGB to CMYK

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