To convert RGB to CMYK, input your RGB color codes to RGB area, for example, rgb (30, 100, 220) To convert RGB to HEX, input codes to RGB area. To convert HEX to CMYK, input your HEX color codes to HEX area, for example, #3b5376. To convert HEX to RGB, input codes to HEX area. Our color code converter will show results interactively. Photoshop will complain, and righlty so, but will do what you ask. Theres no way to convert a 3 channel curves layer to a 4 channel curves layer. Because they adjust differnet things. See CMYK is the inevrse of RGB so even the curves layer is now totally different. * Now you can be smart about this and merge down the adjustment before conversion. Get a color chart that cross-references RGB, CMYK and PMS. Work from those numerical settings, not what you see on the screen. I would just work in CMYK, but if you work in RGB you can convert to CMYK when you export to PDF for printing. Supply the CMYK reference numbers with the file to the printer. So you would basically use OpenCV to write the raw C bytes, then the raw M bytes, then the raw Y bytes and the raw K bytes into a single file and use system () to call that utility. I used this command line: raw2tiff -w 1024 -l 768 -b 4 -i band -c lzw -p cmyk CMYK result.tif. So my image was 1024 pixels wide, 768 pixels tall, consisting of 4 In the “Source” section, click the “Browse” button and select the folder that contains the images you want to convert. 3. Make sure the “Destination” is set to “Save and Close”. 4. Under the “Action” drop-down menu, select the action you want to perform on the images (in this case, “Convert to CMYK”). 5. Exporting .psd to .jpeg changes CMYK to RGB. I know JPEG is not ideal for printing, but when for whatever reason the printer requires a JPEG rather than a TIFF Photoshop is not making it easy. When I want the ease of exporting using the export dialog, the JPEG is ALWAYS converted to RGB. When "Convert to sRGB is unchecked. Anyway, after converting to CMYK mode, just use File > Save, and Photoshop will not let you save it but will ask you to "Save As" where you can choose from all available file formats that can save CMYK images. Even though Photoshop does let you save your PNG file in CMYK it still does not show the change in InDesign. Convert RGB image to CMYK and match blacks to rich black. I'm working on a CD packaging which will be printed in 4-colour offset. I have a rich-black background over which is placed an RGB image bitmap image. On one side, the image has a opacity mask so that it fades out over the black background. The blacks in the RGB image are virtually 0R 0G Press Option + I + M + R keys Photoshop shortcut to convert CMYK to RGB mode. Note To convert RGB mode to CMYK mode, press Option + I + M + C keys together. Pro Tip: Check if the image has converted or not by repeating steps 5 & 6 of Method 1 and see if the option RGB color is ticked or not. The Image > Mode command was around long before Convert to Profile. Image > Mode uses the “locked in” colour settings, while Convert to Profile can change settings “on the fly” with live preview. For most conversions Image > Mode has been depreciated and Convert to Profile is recommended as it is more flexible. MOVI.