What is .COS file extension?
Image settings file created by Capture One, a program used for editing and organizing digital photos; saves image adjustments (exposure, color temperature, white balance, etc.) and other nondestructive edits for a photo.
When image adjustments are made, Capture One saves a COS file that has the same name as the original image but with the added ".cos" extension. For example, if you make adjustments to myphoto.jpg, Capture One saves a myphoto.jpg.cos file. When final adjustments are made, you can process, or "bake," the settings and photo together into an output image with all adjustments applied.
You can see a list of software programs here on easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.