If you are working with paper negatives or you are intended to create cyanotype or gum bichromate print from a digital photo, you have to turn the photo to negative. Fortunately, you don’t need other software, with a dirty trick, Capture One can do it for you.
I have already scanned and imported a paper negative of pinhole photo of the Mai Manó House that used to be the home and workplace of Manó Mai, the former imperial and royal court photographer of the Austro-Hungarian Empire. The Hungarian House of Photography can be found here today.
Now you should go to the Exposure tool tab (that little histogram like icon over the tools) and make a cross in the Levels tool. Grab the white point slider on the right side, below the histogram and drag almost all the way left (to make a little space for dragging the black point slider) then drag the black point slider all the way right. Now, you can drag the white point to all the way left and you are done.