Odoo PDF Attachment Compression
1- Compress pdf based on a set of rules
2Flexible rules for compression:
- By model where pdf are uploaded.
-By ratio; allows to compress images inside pdf to configured ratio.
-By minimum image width; allows to compress images inside pdf which width bigger than configured width.
-By quality; allows to compress images inside pdf to configured quality.
-By size; it allows to compress images having a bigger size than the configured size.

Checkout below step-by-step guide:
Configuration
- Configuration: Setup a compression rule
- Select the modules where pdf attachments to be compressed

- Set the compression ratio

- Set the optional minimum image width inside pdf attachment

- Set the optional minimum size of the image

- Set the optional newer than/older than days to compress.

- Set the quality of the compressed image (value between 0 and 100 where the larger the value, the higher the compression but the lower the quality).

- In Odoo, storage is done by content. Thus, if the same pdf was uploaded twice, it will be saved on the disk once.
- Thus, there is an option to match all similar pdf, compress them and delete the uncompressed pdf.
- To activate this feature, check the “Replace All”
- If you want the scheduled action to run this compression rule daily, keep it active.
Scheduled Action
- Upon installing the module, a daily scheduled action “Run attachments compression rules” is added automatically

How it works
- Add pdf: Add some pdf attachments that contains images in the models.
In the following example, we selected the sale model in my compression rule. So, we are adding 2 pdf files which contain images.

- Run the compression rule: Go to the corresponding compression rule and run it. The pdfs satisfying these rules should be compressed.
The system will show a pop up with the details of the compression:
compressed pdf and total size reduction

- Check the results: Go back to the model where the pdf was uploaded and verify the results.
Download the pdf and check the size reduction.

- File Store: Notice that upon running a compression rule or when the scheduled action runs them,
the size of the file store is reduced if Replace All was checked