Convert pdf file to monochrome

[zain910128]

How can i convert a file to black and white / monochrome ?

[pubpub-zz]

There is no dedicated functions for that. for text and drawings, you should be able to look through contents looking for color operators (CS, cs, SC, SCN, sc, scn, G, g, RG, rg, K, k - see §4.5.7 in pdf 1.7 specification) and replace these lines with G or g operators with the adequate gray definition) but you will have to define your own translation rule.
for images, you can use the images[ ].replace() function to replace the image once converted to gray or black

[zain910128]

Thanks for your reply.

Is it intended to be added to pypdf as a feature at some point or is it out of scope for this library ?
Can you also point me to any other libraries that you recommend for such a transformation ?

Thanks

[pubpub-zz]

pypdf allows to have capabilities to access/modify data. It is not integrate such specific function.

[zain910128]

I see. Sometimes we are looking to make changes at page level or file level without going to each part of the page individually.
Based on what you're saying, it sounds like pypdf is more focussed towards modifying individual elements and parts of a page. Is that right ?
Do you have any recommendation for a library that operates on page level and file level transformations like scale and page size, greyscale colours, rotation, etc ?

[pubpub-zz]

pypdf can do page scaling, merging, rotation. for color changing, pypddf can helps you but you need to build your specific code. I know no other library

[stefan6419846]

Is it intended to be added to pypdf as a feature at some point or is it out of scope for this library ?

I would consider this out of scope for pypdf as it is too specific, although you are of course invited to share your own implementation under a free license or (depending on the implementation size) provide this as an example for our docs.