PdfCMYKerLite is a wxPython GUI front-end for Ghostscript gs
and ImageMagick convert
, which uses the Ghostscript tiffsep
device to obtain CMYK separations of a PDF document, which are displayed in the application. The application then offers a limited possibility to "remix" the CMYK channels (for instance, copy the K channel to the three other ones to obtain a rich black), and then finally uses gs
and convert
to obtain a rasterized version of the currently browsed page with remixed CMYK channels.
(1). Choose a path to PDF file to open, by either:
Note that either of these three methods simply set the file path to be opened - but do not open the file directly. When a file path for opening is set, it will be colored gray.
(2). With a file path set, press the 'Open' button
PdfCMYKerLite calls Ghostscript to obtain .tiff
thumbnail separations, and shows them in the application. The top part of the application shows the "input" thumbnails: the color image, and then the original CMYK separations of the given file and page. The bottom part of the applications shows the "output" thumbnails: the separations mapped accordingly to the mapping settings, and then a color version derived from the mapped separations. The file path in the top text field changes to black color, to indicate that the file is opened.
(3). Use the numeric spin control (either click on the arrows, or type a number and press ENTER) to get to the page of interest. Each time a new page is set, a new set of "input" and "output" thumbnails is derived and shown accordingly. Also, each time a new page is set, the text field on the bottom of the window is updated with a new PDF output filename (in the same directory as the original file).
(4). Set the output CMYK channel mapping; you can choose one of the mapping presets:
You may also want to change the output resolution at the desired ammount of DPI (dots per inch) at this point, by typing in the desired value in the 'Output' text field at the top right of the application. Also, you do not have to use the mapping presets - you can also manually change the mapping for each individual channel.
(5). Confirm the Output PDF file path
If you're not happy with the autogenerated Output PDF file path, you can either:
Once you're happy with the output PDF file path, you can now press the "Save" button on the bottom right of the application window - and after some seconds, the output file should be generated. At this point, if you have a valid path to a PDF viewer set in PdfCMYKerSettings.py
, it will be started with the output PDF file, so you can inspect the output.
The PdfCMYKer
part is because, well, the application deals with PDF and CMYK. The Lite
part is because originally I wanted to make this application by pulling in Python API interfaces to ImageMagick and Ghostscript inside the application, and do the rasterization and CMYK channel manipulation through that. However, that turned out to be too much work, so I decided to just make the GUI (wxPython) part of the application call the ghostscript
and convert
executables instead, and in that sense it is a much more Lite
solution than the one originally intended.