cmyk

Is there a place where I can get the formula which photoshop uses to convert rgb to cmyk? I know there are formulas on the web, but photoshop does not use this formula. It converts the collors different. Can someone tell me the photoshop formula? Thanks! Most likely, Photoshop uses a color profile for converting RGB to CMYK. If you want to do the same with a .NET language on Windows, then there's an API for it: float[] colorValues = new float[4]; colorValues[0] = c / 255f; colorValues[1] = m / 255f; colorValues[2] = y / 255f; colorValues[3] = k / 255f; System.Windows.Media.Color color = Color

I am having much trouble to get ImageMagick's identify to, well, identify a PDF as CMYK. Essentially, let's say I'm building this file, test.tex , with pdflatex : \documentclass[a4paper,12pt]{article} %% https://tex.stackexchange.com/questions/13071 \pdfcompresslevel=0 %% http://compgroups.net/comp.text.tex/Making-a-cmyk-PDF %% ln -s /usr/share/color/icc/sRGB.icm . % \immediate\pdfobj stream attr{/N 4} file{sRGB.icm} % \pdfcatalog{% % /OutputIntents [ << % /Type /OutputIntent % /S/GTS_PDFA1 % /DestOutputProfile \the\pdflastobj\space 0 R % /OutputConditionIdentifier (sRGB IEC61966-2.1) % /Info

I need to convert RGB PDF into CMYK PDF. I need to have pure black color for texts. It seems (thanks to comments below) term "black point compensation" is wrong. I took it from Adobe Acrobat where it works exactly how i need. I thought gs has same feature. I use ghostscript 9.16 If i got it right there is -dBlackPtComp option, but it does not work for me. Ghostscript command I have tried is: "c:/Program Files/gs/gs9.16/bin/GSWIN64C.EXE" -o testing_black_cmyk.pdf -sColorConversionStrategy=CMYK -sDEVICE=pdfwrite -dOverrideICC=true -sOutputICCProfile=c:/Windows/System32/spool/drivers/color

I am working on a project that requires me to separate out each color in a CYMK image and generate a halftone image that will be printed on a special halftone printer. The method used is analogues to silk screening in that the process is almost identical. Take a photo and break out each color channel. Then produce a screen for the half tone. Each color screen must have it's screen skewed by 15-45 (adjustable) degrees. Dot size and LPI must be calculated from user configurable values to achieve different effects. This process I am told is used in silk screening but I have been unable to locate

Is it possible to write a script for Adobe Illustrator or some other tool that will read the contents of a number of PDF files and convert all the RGB colours to CMYK? If so, could somebody please point out some of the steps involved, or where to find more information on this? This answer is not for Illustrator, but for 'some other tool' , namely Ghostscript (download gs871w32.exe or gs871w64.exe ). Ghostscript allows you to 're-distill' PDFs ( without an intermediate conversion to PostScript, the dreaded 'refrying' detour). Try this command: gswin32c.exe ^ -o c:/path/to/output-cmyk.pdf ^