Converting to PDF/A - images size goes way up in file size

[zarkogajic]

Hi Support,

I'm saving a document as PDF/A:

image.png

The original document has ~80 MB, with space usage as:

image(1).png

After the conversion, the PDFA has ~550 MB with:

image(2).png

Note the size of images in PDF/A version.

Is this to expect?


-žarko

[Daniel - PDF-XChange]

Hello, zarkogajic

The conversion to PDF/A should show a report at the end of the process. If it needed to recompress images to match PDF/A's requirements, or makes a similar notes of changes, than yes, such a change could be expected.

Could I ask for a copy of the document in question, and a screenshot of the conversion report you get after saving?

Kind regards,

[zarkogajic]

Hi Dan,

Sorry, cannot send the document as it is under NDA.

Report:

image.png

-žarko

[Daniel - PDF-XChange]

Hello, zarkogajic

If you uncheck the "rasterize unembedded fonts" option, does that help the situation at all?

Kind regards,

[zarkogajic]

Hi Dan,

I've tried - same result.

But, here's what I noted: PDF/A conversion recompressed all images and all now use "zip" compression - which has affected the size of the images. Images in the original document use "JPEG 2000" compression.

If I manually try to recompress an image, in the original document, and change, for test, the compress method to "zip" - this is what the end result in PDF/A is/would be:

image.png

So, the solution to this would be *not* to recompress images during the PDF/A conversion, OR add option to specify which compression to use (allowed by PDFA standard).

-žarko

[mCHSNUg5Pz8cPap]

But, here's what I noted: PDF/A conversion recompressed all images and all now use "zip" compression - which has affected the size of the images.

The same thing happens with the Enhance Scans - Deskew feature. It also takes the original images and recompresses them with zip. See viewtopic.php?p=193068#p193068
Maybe if they improve it here, the improvement can be applied to the Enhance Scans feature as well.

[Daniel - PDF-XChange]

Hello, mCHSNUg5Pz8cPap

It is possible that improvements to compression would help here, but as Zarko mentioned, there shouldn't be any need to do a recompression in the first place, unless there is some unique aspect of PDF/A forcing a recompression action, even though the current image format is supported by PDF/A...

I have passed this up to the team for review, but I cannot be certain which way this will go at the moment.

Kind regards,

[zarkogajic]

Hi Dan,

Thanks.

Please do update the topic when you have some info from devs..

-žarko