I’ve transformed several CBZ files into PDF with success and nice quality with last Pre-release 3.2.11874. Good work !
I’d like to know if more recent acrobat versions are planned in further developpments with maybe user choice : 1.7; 2.0; pdf/A ?
1.4 was released a long time ago : in 2006
Newer PDF versions are probably a whole lot more complex to implement, plus since this is basically a bonus or nice extra feature in what’s primarily a pure reader and not an editor, I wouldn’t hold my breath if I were you.
Of course only the dev can talk about implementation for sure, however, just to make your case stronger, why do you want this? What advantage do you hope to gain with newer versions of the spec being supported, especially given that the sole purpose of this is only to bundle up a bunch of images into a PDF container?
When using GhostScript the version is now usually set to 1.7 so Acrobat 8 and above is recommended / required for viewing. Note Linux & Portable versions stopped with version 9.
The “version” is an indication of the files ability to be read by legacy viewers thus good if it is set at 1.4 (Acrobat 5) or for even more users if 1.3 (Acrobat 4)
The use of PDF/A flags indicates that amongst other requirements it will work with 1.4 compatible viewers and the fonts are included, in a particular fashion but that would not generally apply to CB image files anyway, thus most SumatraPDF image files meet PDF/A-1b – Level B (basic) conformance (except the version 1.7 ones)
Here I have taken PNG scanned pages in a folder and loaded that folder in SumatraPDF to generate a PDF then just for you set Irfanview to force PDF/A compliance NOTE Irfanview will keep the version at 1.4+ even if it was previously 1.7 from GhostScript
compatible 
Changing the version of generated PDF document makes no difference.
In fact, you do want the lowest possible version that works because more software will be able to read the files.
PDF format is versioned because they keep adding features.
If the document uses a feature introduced in 1.7, it has to set the version to 1.7 so that the software that e.g. only understands 1.4 features won’t attempt to render it (because it couldn’t).
But if the document only uses features available in 1.4, it should set the version to 1.4.
The main advantage is the format longevity.
My company doesn’t accept 1.4 format anymore and ask for 1.7 or above or pdf/A, So I’m not sure I will be able to read my comics in 20 years
What exactly does that mean?
And why do you care? Do you give your comic books to your company to read them?
Like I explained above, 1.4 is more compatible and therefore will be more supported than 1.7, today and in the future.
There’s no rational reason to not accept 1.4 format if you accept 1.7. It’s not my job to accommodate irrational companies.
Even if you’re able to access today’s comic files a couple of decades from now, what’s the guarantee that future software will be able to handle v1.7 PDFs? So is Sumatra supposed to add support for v2.x, then v3.x and so on, and you plan to update all your comic PDFs every few years to newer versions? No offence, but this sounds ridiculous TBH.
In any case you have the definitive answer from the dev himself above, so that’s that.
Thanks for all your responses
I can’t seem to understand the dilemma about versions. If you successfully converted cbr to pdf, just leave it like that. Core elements of the PDF file are not changed, the version should not worry you to much.
I normally would remove a link to a Software as a Service as not needed for a feature within SumatraPDF. However due to testing some issues that SumatraPDF is having I have left it for now as it does illustrate Online converters will also set PDF Version correctly to 1.4 (the reason for this topic)
Here is the result showing that 365 website has set PDF output to 1.4 but broke the input page badly dropping colour, rescaling down, degrading compression and spitting pages in this case.
the test file should look like this before and after
