Page PDF export size significantly increases if page consist of .jpeg/jpg images

Issue Summary

Page PDF export size significantly increases if page consist of .jpeg/jpg images

Environment

Confluence 7.0.1, 6.15.9

Steps to Reproduce

1. Prepare  .jpeg and .png files. Note the size of both files.
2. Create two Confluence pages. Add .jpeg image to the page A and .png attachment to page B
3. Export both pages to PDF
4. Check the size of generated PDF export files

Expected Results

Size of PDF export is similar to the size of the images (or smaller due to the compression)

Actual Results

• PDF export from page A with .jpeg attachment (85KB) is 422kb
• PDF export from page B with .png attachment (355KB) is 180kb

Notes

• For jpeg attachment (3.2mb) page pdf export increases to 17mb
• Adding multiple jpeg attachments multiplies the increase in PDF export size

Workaround

We found a 2 steps workaround which consists of:

• Using the Export to Word feature to get the Confluence page saved as a doc file first
• Then, open the doc file in Microsoft Word, go to File > Print and select the Microsoft Print to PDF in the printer dropdown list to save the .doc file to a .pdf file.