Rgb or cmyk is there a gain/advantage working on photos?

Hi
i use almost every time RGB
but now i'm thinking if there is a gain/advantage using CMYK in photo editing
well i don't know
is there a gain advantage in the CMYK ?
if yes , why and when ?
thanks
have a great day

There is absolutely nothing to be gained.
CMYK has a more limited colour gamut than RGB and is intended for images that are to be printed on a printing press where the colours are also restricted.
To all intents and purposes you can forget CMYK.

Similar Messages

Smart Objects: RGB inside CMYK

Just two days before completing a two week job the client decided (still dont know why) the job had to be delivered with open layers on CMYK.
After two weaks and 6 jobs and hundred of layers latter had almost all work done..in RGB. I started to panic thinking of the time I would waste just appling curves,levels,etc... to every layer,while keeping things open if they wanted last minute changes.
Thats when it struck me..why not leaving everything as it was (RGB) and convert it to a smart object and then convert the parrent file to CMYK?
I has suprised how it works just fine.In the end the client agreed it was better to keep things as they were,but it sounds a really nice possibility and to some extend makes perfect sense as one would retain the full Gamut of RGB (AdobeRGB or any other) and could convert to proper CMYK acording to needs.
As anyone experienced this?

Mark -
There are a few gross errors in Photoshop that are seen as bugs, but go uncorrected for years due to the amount of work needed to fix them - not to mention - get it worked into the correction cycle in development. Marketing is steering the train. Go think about that oxymoron for a few weeks...
;o)
One major problem is the conundrum of being able to open an untagged file, assign a color space, then look at it. That in itself is counter intuitive and basically a HUGE hole in the application with respect to color management. With the new proposed architecture of creating the entire application Smart Photoshop - You not only eliminate this issue, but also have created a new and improved workflow - integrating source color images into the working space, tagged or untagged, with consistency for all. Adobe products are now far and wide enough to have the majority rule, so why not capitalize on it and implement a global workflow. This logic works for many industries Adobe serves. From 2d, 3d to motion video, cell phone, bio medical, and who knows what's next. It's image history preservation in its simple form.
In English, whittle down 9 options to 2 for color policies and change the logic between RGB and CMYK file handling. Convert to working space. Have the working space 32 bit Pro Photo RGB. Files flow into it as well as color space conversions. Now remember, this is a choice feature and not a force fit. It's a marketing born inception that caters to the masses for best practice. If you want to work outside that environment, its your choice, but it's not advisable unless you are resurrecting trash, re-assigning really bad pictures, or it does not work for your requirement and a new additional per-dim needs to be created. I'm offering a choice. Two choices to be specific. Road or off road travel. For here now, and tomorrow. It's a creature of growth, just like the implementation of Smart Objects that has morphed more possibilities as well as options. But Smart Objects is a representation of Adobe's expanded free for all mentality to push the envelope of development for market share. My advice is to back on the whizz bang wow factor and get some damn control of the features grained in deep rooted experience from power users....
Smart Photoshop is needed because users are not getting it Gentleman and Ladies. Expecting most users to become geeks is not going to happen. It's a given from a marketing stand point, but they refuse to see how to address it for one reason or another. Maybe too busy dealing with the company merge and product integration. Im pretty sure its quite an undertaking, but its time to make the best - better....
I remember Bruce Fraser talking about Chris and Thomas wanting 12 ish choices for color policies fearing too much restrain for growth. Thank you Bruce for 9, but my friend, we need even less.... Smart Photoshop gives 2 choices. Structure or Chaos. Right now we only have chaos. My vote is to have uniformity with very little user understanding and awareness. That's good implementation. The software has to become intelligent people.....
I'm game. Who has balls here?
nice to see ur pair Rich.

Is there a menu option in basic Adobe Reader than will enable me to check if a PDF is set in RGB or CMYK?

Is there a menu option in basic Adobe Reader than will enable me to check if a PDF is set in RGB or CMYK?

No. Acrobat Pro's preflight is the tool for checking this sort of thing but you should be aware that it isn't a simple RGB versus CMYK. A file can contain any mixture of either, as well as other colour spaces (greyscale, Lab, spot colour). So in preflight you are looking to be told not "is this file CMYK" but "does this file contain any non-CMYK elements". Preflight can also check other prepress needs like a minimum resolution.

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.

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

Conversion formulas from RGB to CMYK

Hi,
I've been writing a Colour swatch tool (in excel! hell yeah!) which allows me to pick a bunch of colours, generate complimentary colours from them, blend between 2 colours in a set number of steps and a whole bunch of other cool stuff, and then output this as a photoshop or illustrator swatch file.
As part of this tool I want to be able to covert the rgb values to cmyk. There is very little information on this on the web and what there is is fairly inaccurate.
For example,
RGB:50,128,128
Converts to CMYK 61,0,0,50 (%) using the formula found at easyrgb.com (this formula is the most prevalent one on the web/web forums)
Photoshop converts these RGB values as CMYK: 80,33,48,8 (%)
While these two colour values are *similar* the ones generated by the easyrgb formulas are nowhere near the photoshop values.
See? stupid useless formulas. (I am aware of the differences and overlap of the two gamuts)
Whilst I know that the conversion done in photoshop is done using ICC templates, and that often these conversions are device dependant, there must be a more realiable way of converting from one colour space to another using good old reliable cold hard maths.
Does anyone know what that might be? you guys at Adobe: I AM LOOKING AT YOU.
Hope you guys can help,
~silvery~
For reference I have included and commented the easyrgb formulas:
First: RGB -> CMY
C = 1 - ( R / 255 )
M = 1 - ( G / 255 )
Y = 1 - ( B / 255 )
Second: CMY -> CMYK
var_K = 1
Initally sets var_K as 1, although this is dependant on variables below
if ( C < var_K )   var_K = C
if ( M < var_K )   var_K = M
if ( Y < var_K )   var_K = Y
This bit finds the smallest value from the CMY range and sets this value as var_K
if ( var_K == 1 ) { //Black
    C = 0
    M = 0
    Y = 0
If var_K (the value that K is calculated from) is 1, then all the CMY values are reset to 0
else {
    C = ( C - var_K ) / ( 1 - var_K )
    M = ( M - var_K ) / ( 1 - var_K )
    Y = ( Y - var_K ) / ( 1 - var_K )
If the value of var_K is anything other than 1 then use the smallest value from the CMY range
K = var_K
The value of K as filtered out from the conditions above

Oliver,
I'm not sure what you mean by the term 'meta' color profiles, but I'll take a stab at what I "think" you are asking. There are some fairly widely accepted "standards" out there for both RGB and CMYK.
In the RGB world, for example, sRGB, Adobe RGB (and to some extent, ProPhoto RGB) have a fairly wide following. These are all ICC profiles, which nail down the boundaries of the color gamut and the definitions of any tri-stimulus combination of red, green and blue. Basically, they are matrix profiles that establish the positions of the Red, Green and Blue primaries, and these positions define the outer limits, or color gamut, of the color space. sRGB is a relatively small color space, so some viewable and printable colors get clipped (sRGB is the general internet, email standard and is widely assumed for many non-color managed appplications, printers, etc). sRGB can handle a fairly wide range of colors, but does clip some colors in brightly colored originals. It has the advantage of being the most widely adopted standard, plus the steps between colors are very close together. I use sRGB for average images, most people pictures, etc. Adobe RGB spreads the primaries further apart, so it describes a wider color gamut. Because the primaries are further apart, the steps are slightly larger from one color to the next, but marginally so. I use Adobe RGB for most of my brightly colored images that will get clipped in sRGB. Adobe RGB is also generally a good choice for images that will ultimately go to a printing press or inkjet. ProPhoto RGB pushes the primaries WAY apart, so it describes a HUGE color gamut...in fact, many of the colors that can be defined in ProPhoto fall outside human vision, and certainly monitors and printers.Due to the wide spacing of steps in ProPhoto RGB, images should be worked in in 16 bit, otherwide you may see some banding and posterization if large edits are made.
In the CMYK world, certain "standards" have been established, mainly for commercial offset printers (both web and sheetfed presses). By creating a standard, they are trying to establish the ink limit, densities, color gamut, dynamic range, gray balance, etc, of a "generic" sheet of commercial printing paper on the average well-maintained press using standard ISO inks, using good process control, mesurements, etc. By it's nature, this process has to encompass a wide cross section of presses, so it may act as a limitation on what some modern presses are capable of, but that's what standards usually do. If a good printer, with a modern press and great process control decides to sidestep the standard, they can probably extend color gamut, dynamic range, etc, but at the cost of no longer being "standardized". If commercial printers are "truly" trying to meet the standard, they will run tests, take measurements, and adjust their entire workflow so it matches the standard, within acceptable tolerances. Lots of shops "claim" to adhere to SWOP or GRACoL standards, but the majority of them don't. Standards for presses make some sense, because blending CMYK inks together (especially if they use ISO standard inks) on paper usually has a reasonably narrow range that works, though the paper makes a huge difference. (the same cannot be said for inkjets, monitors and many other processes, so they generally do not have standards). So for presses, there are standards for matte and coated papers, web presses, sheetfed presses, newsprint, etc. Each of these standards has its own ICC profile (or a family of profiles) that establishes ink limits, color gamuts, etc.
All ICC profiles have the necessary tags and data to comply with the ICC specification. One of those requirements is a "profile connection space", which is usually L*a*b* or a variant. So, an file on your computer may be tagged as an Adobe RGB file, and if you wish to prepare it for a sheetfed press using glossy stock, you could convert the file to GRACoL2006_Coated1v2.ICC (an industry standard profile for No. 1 coated stock on a sheetfed press). Since both files have the ability to "speak Lab" a translation can be made from one color space to the other. The numbers in the Adobe RGB file will be converted to L*a*b* (the universal translator), and then the L*a*b* numbers will be converted to CMYK, specifically GRACoL2006_Coated1v2.ICC. So, now you have a file in CMYK space with new numbers. It is worth noting that RGB has only three colorants to define colors, but CMYK has four. So, while in RGB there is only one way to define a specific color, in CMYK, there are many possible combinations that can generate many colors. This adds complexity to the equation. The CMY colors are called subtractive primaries, and are opposites of RGB (additive primaries). The "K" (black ink) is added for text, line art, neutrality, extra Dmax, and because the CMY inks are not pure and don't deliver a true black all by themselves. If the inks and paper were perfect, you could theoretically get away with CMY all by themselves, except for registration issues, text, line art, etc. Also, the additional "K" ink can help reduce the total ink limit, save ink, reduce costs, and improve quality.
Sorry for the book. This is not a simple subject, and we have only touched the surface.
Lou

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

Rgb to cmyk

Is there a way to change the color makeup of ads from rgb to cmyk? I was not the creator of these ads for my newspaper but the printer needs me to change them and get rid of the built black. So, I guess I just need to change the black to pure black.

switch to CMYK color, add a Selective Color adjustment layer and change the Blacks

Rgb to cmyk turns white brown

Hi Guys
In previous versions - changing from RGB to CMYK or vice versa would change the colours slightly but ever since CC when I change one to the other my white
goes brown and there is a yellow tone to the image.
Has anyone else experienced this - it's not slight either see image. I haven't adjusted anything - the original CMYK is on the left and
when I make it RGB - it goes brown.
Has anyone else had this issue?

I'd try a new display profile first. Recalibrate, or if you don't have a calibrator use sRGB (or Adobe RGB if your display is wide gamut).
Everything in Photoshop passes through the display profile. If there's a problem with the profile it can happen that one conversion goes bad but not another.
On Windows a common cause for this is bogus manufacturer profiles pushed through Windows Update. Mac isn't as susceptible to this, but there you have an added complication called ColorSync (which is where the actual profile conversions are done). So if a new profile doesn't fix it, you probably need someone with Mac OS X expertise.

RGB to CMYK gives me a white glaze? how to get rid of it

In photoshop cs5 when i convert an image i am working on from RGB to CMYK i get a white glaze over the image? as if i have added a photo filter or something? do you know how to prevent this on a mac computer?

Apple Custard Studios wrote:
…yes i can see that it is broke, but if you look in your last post the before image is in there for some reason, and the after picture is at the top in the earlier discussions.
Sorry, I don't understand what you're trying to say here. How can the "before" image be in any post of mine if I have never been able to see it?
The image I posted in my post, was your "after" image CORRECTED by me as explained in that post:
"Converting it to sRGB and setting the black and white points via a quick Auto Levels adjustment, brings about an improvement."
In other words, I downloaded your "after" image, opened in Photoshop, went to the Edit menu and used Convert To Profile to convert it to the sRGB color space, then I ran and Auto Levels adjustment. That's how I fixed your mess.
Apple Custard Studios wrote:
Hi station_two
…When i convert from rgb to cmyk, i SIMPLY GO: Image > mode> then click cmyk?…
Geebus Chrysler! No, that is indeed not just "primitive" but totally wrong. Go to the CONVERT TO PROFILE menu item in the Edit menu in Photoshop, and from that menu select the specific CMYK profile you want (or your printer requests). Be careful to select CONVERT TO PROFILE, do not under any circumstances choose "Assign Profile"! Converting to the appropriate CMYK profile will also automatically change the image mode to CMYK mode.
Apple Custard Studios wrote:
…which i am unsure it it may mean i have wrong profiles set, but if so what would i need to change it to?…
Apple Custard, it's obvious that you have no clue as to what Color Management is, and teaching you Color Management step by step here exceeds the scope of what can be accomplished in a forum. A good place to start reading up on it is here:
http://www.gballard.net/psd/cmstheory.html
In a nutshell: Your Monitor profile should be the file resulting from your calibrating and profiling your monitor with a hardware calibrator puck. Calibrate and profile your monitor regularly and often. Your monitor profile thus will be device-dependent, specific to your monitor.
Your working space, on the other hand, should be a device-independent profile, such as Adobe RGB or sRGB. It should NEVER, ever be your monitor profile.
Your target profile when printing should be device-dependent and specific to the combination of ink, paper and printer model you'll be using. For the web, create a copy of your image file and convert it to sRGB, then save it as a JPEG as needed.
Good luck!

RGB to CMYK to commercial printer

We are using CS2 InDesign and Photoshop 7 on a PC. I am putting together two
large books. One insert section of the first book has color photos. I have
to prepare these color photos for a printer located in China. They want all
images to be CMYK .tiff.
I have an assortment of about 100 images from various sources around the
world, there are .tif, .jpg. .bmp, and .psd. All of them appear to be RGB.
There are images with: 1) no color profile, 2) sRGB IE60966-2.1, and Adobe
RGB 1998. Do all images need to have the same RGB color profile before
converting to CMYK?
I have been converting all of these to .tif (and using a single dpi/pixel
resolution for
all images).
Do I just select/save as color mode CMYK? Or are there special
settings/profiles I need to know about. Is there anything special for China?
The printer's English is not that clear . I was hoping that someone in this
group would be familiar with RGB to CMYK conversion.
Also, it appears that the final PDF pages (with embedded Tiff images) will
be very large. The first complete book for this project (there are two
books) looks like it will be about 20GB. The second book looks like it could
be 12GB. Both books together equal about 1,000 pages and have about 1,000
images. 90% of the images are grayscale. What are the current technologies
for sending large projects like this to a printer?
Thanks
ps, the Photoshop group suggested that I write to this group.

Tech....
In the conversions, are you referring to conversions of B&W or color images? I'll assume color for the moment.
Assuming your monitor is properly calibrated, and assuming you are viewing your color images on your monitor, your conversions should keep "in gamut" colors the same. You will, however, probably see some loss of dynamic range, color, and saturation as you enter CMYK. If the color and dynamic range of the original is all within the destination CMYK gamut, you should see very little, if any, shift. The sad fact is that CMYK on press has limited dynamic range and color, especially compared to a bright monitor. This is generally true, though CMYK can print some colors that lie outside the typical monitor's gamut.
If you have a brightly colored original in RGB mode, then you should experiment with both perceptual and relative colorimetric rendering to see which one looks best. This is an image by image thing. Relative colorimetric will reproduce all "in gamut colors" as accurately as possible, then will take out of gamut colors and bring them to the closest printable color. This can cause loss of detail and 'piling up of colors' as you near the boundaries of the image's color gamut in the destination CMYK space. Perceptual scales ALL colors and preserves the relationships between colors, which sacrifices color accuracy and saturation, but sometimes looks more natural, especially if there are a LOT of out of gamut colors. Pick whichever ones looks best overall.
Then, once in CMYK, make minor curves adjustments to tweak if for CMYK. Just be careful not to push it too far, especially in the deep shadows, since you may push beyond the ink limit of the press. For example, if you convert to US Web Coated SWOP v2, the ink limits are set at 300 total. If you drastically darken the shadow areas, you could end up with an ink limit of 320, 330, 350, etc. Knowing the ink limit of the press will help you stay within those limits. Final tweaking in CMYK is usually a good thing.
How did you determine that the images were dull with too much magenta? Did you print a proof on a calibrated printer, or is this just your screen display? Or is this from a printed image off the press? I have a well calibrated monitor and accurate custom profiles for my inkjet. If I am sending a job to a press that supposedly prints to US Web Coated SWOP, I can proof that file on my inkjet and get a very good match. We need more information to know exactly what you are doing and how you are assessing your images.
Normally, I do the conversion in Photoshop, using the rendering intent that looks best. Then I tweak the image in CMYK to get it looking its best. I usually have the press profile, but sometimes work with a standard profile if no custom profile is available. I leave the image tagged with my conversion profile. Then, I usually place these images into InDesign, with the profile intact (color management turned on in InDesign). I right click on the placed image to be sure that the profile and rendering intent are set to what I want. Then, I can either supply the InDesign file to the printer, or convert to PDF (leave color unchanged) and make sure that all profiles are included. InDesign should export each image to the PDF properly, along with profile and intent. I have never sent to job to press using Photoshop...only InDesign or Illustrator.
BTW, rendering intent is only used when getting an image from one color space to another, such as a conversion from RGB to CMYK. You do that, choosing the one that looks the best. Once it is in the destination CMYK space, rendering intent is no longer needed, since all the colors and tones have already been remapped into the final space. Rendering intent is just used to help us handle those out of gamut colors.
Hope this helps.
Lou

How can you tell if a PDF is RGB or CMYK?

From the screeshto below I am finding the only way to tell if a PDF I receive is RGB or CMYK, is by the transparency blending space. Are there any other ways?
The drop shadow on the chip is showing cyan, along with the yellow arrow. The original files do not have cyan in these areas. Is this because the PDF is being saved as smallest file size, which converts CMYK to RGB, then in Acrobat we are coverting RGB values back to CMYK, and with those color conversions you cannot proof Smllest file size PDFs for CMYK breakdowns.
What are others using out there in proffing PDFs for color, smallest file size with color conversion set to no? Doing that makes our PDFs about 150% to 200% larger and they often wont fit in email then. Are there any secret ways of proofing a standard smallest file size PDFs for accurate CMYK breakdowns?

In Acrobat Pro 9:
Advanced Menu to Preflight
Upper Right corner of Preflight dialog box click on "Options"
then select "Create Inventory"
deselect everything except colors and click "OK"
it will analyze your document and return with the number of "plates" as well as the names of the plates...

How to make a script to convert RGB to CMYK as black 100%?

Hi guy
my customer sent me a book (144 pages) for print but all of them are RGB and Tiff, she scan them. there are on the page some texts and pictures. The text are R=30 G=30 B=30.I think if I can make a script I will do it very soon to black 100%, but unfortunately I dont know anything to make script
anybody can help me ?anybody can make it for me ?

We need to know some more information.
1. The book consists of 144 pages, and each page is in fact an RGB image in TIFF format.
    Correct?
    That means, the text is already rasterized, but with low resolution (no more than 300ppi).
    A very bad starting point, in my humble opinion. For offset printing this is not acceptable.
2. Is the printing process offset printing or by digital printing?
Nevertheless we may think about a conversion of these images into CMYK K-only (one plate
per page) .
a) Increase contrast until R=G=B=0 for text.
b) Convert each image into Grayscale, using a so-called Black-Ink-Profile, for instance
    Black-Ink-ISOCoated-v2-eci (can be explained later)
c) Make empty CMYK image, here for ISOCoated-v2-eci, and paste the Grayscale into the
    K-channel. All further handling happens as CMYK file for the process ISOCoated-v2-eci.
    Void plates CMY don't matter.
    Post #12 here:
    Re: Colour shift (from CMYK = 0 0 0 20 to Grayscale K = 22 !)
All this can be done by an action (I hope so...).
Much better would be a new start by InDesign with typographical text (K-only vector instead of raster)
with images in RGB or CMYK, taking into account the intended process.
Note: Photoshop can deliver vector text, if exported as PDF.
Best regards --Gernot Hoffmann

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).

RGB vs. CMYK Colorspace - Which is best to work in?

I'm designing a document for a client, within in InDesign. Up until my last save, I've been ignoring the notice about InDesign being set in the RGB colorspace. On my last save, I changed it to the CMYK colorspace and all my linked images got lighter (some not in a good way). I understand the difference, but my question is - for sending this to print, what is the standard colorspace that most printers use? Should I be designing in the CMYK colorspace or RGB?
Also, when I edit my photos, I switch back and forth between modes to get the best results, but what is the best mode to save them in - RGB or CMYK? I've heard conflicting answers.
I realize that printers print in CMYK and while it would make sense to save photos and InDesign docs in CMYK, I've heard people say it's best to save in RGB. Please help. If you could also please explain your answer, just so I can gain the knowledge on this subject and understand why I'm doing what I'm doing.
I should also mention that I'm working in CS3, but I save to a PDF from CS5.

InDesign by default is set in the CMYK colorspace which is what most people who use InDesign would need. The only way to set InDesign into RGB is to declare your document intent as "web" which is a bad idea for any document that you might eventually print. If you know from the get-go you will be printing your document, set InDesign to the print intent. If you are designing for the web, set it up in RGB (web intent).
As for your images, I used to convert them to my CMYK profile early on and work that way but changed my methods a few years back as Photoshop has less editing options for CMYK images. My advice would be to keep the photo's/images in RGB until you are ready to send the document to print, then convert to your CMYK profile - IF sending to a conventional 4 color print press. If you are sending to a digital printer (including desktops), it matters less about converting to CMYK.
Of course you could keep the images in RGB anyway and let InDesign (or the PDF export) convert them all to the same CMYK profile but you might see color shifts, as you have been experiencing. By converting them yourself in Photoshop before you send to print, you see the changes and can adjust accordingly.

Rgb or cmyk is there a gain/advantage working on photos?

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