Add support for exporting pdf to image

[werenall]

Implement a namespace for exporting a PDF or PDDocument to a BufferedImage

[Re #55]
This PR also slightly changes the prerequisites for split function
Previously it only allowed strings as inputs. IMHO it should also
accept files.

[dotemacs]

Hi @werenall

thank you for the PR.

I'd like to think about this a little bit.

But from a quick look:

you seem to have extended the functionality of an existing function and added a new feature in the same commit message. I think that this should be split in separate commits.

This is just from a quick glance.

[werenall]

Yeah, I agree. Take all the time you need and just let me know in a bulk what I can improve.

[dotemacs]

To summarise:

The changes in pdfboxing.split are they in any way related to this pull request?
I don't see how they are.

The same with pdfboxing.merge, is it related to this pull request, feature wise?

I'd say that only the addition of pdfboxing.image is relevant for this pull request.

Since you mentioned in #55 why you've created it, I have some context, but maybe you can add an example on how it can be used in the README?

For me to add this PR, it would be nice to see the following:

• removal of the changes from this PR from pdfboxing.split & pdfboxing.mege
• a clear example of the usage of the function pdfboxing.image/export-to-image
• also, why does it only take the first page? I get that it satisfies your use case when creating thumbnails, but let's say that somebody wanted to use nth page from the PDF document, is this 0 on this line https://github.com/dotemacs/pdfboxing/pull/56/files#diff-f29a5a4bdf7329ef9a0076770cb59571R27 used to specify that first page? if it is, maybe it can be set as an option using :or in the destructuring argument?

Thank you for your work

[werenall]

Ok @dotemacs, I think I resolved all your comments. Let me know if you still would like some fine-tuning.

[glfeng318]

how is this PR going? i'm looking into this feature too

[jgrodziski]

HI @dotemacs, I wonder if you plan to merge this PR?
thank you for your work on this lib.

[avocade]

Gentle ping ☺️ Also re: this comment: #55