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PDF Compression not optimal (comparison with Webtools)

Hi Aspose team,

please find attached project with test project and documents where I compared compression between Aspose components and one of free Web tools.

- Original document (1.pdf) has size of 16.780.369 bytes
- Web tool compressed document (1.compressed (WebTool).pdf) has size of 6.731.730 bytes
- Aspose compressed document (1_compressed (ImageQuality 60).pdf) has size of 12.284.689 bytes
- Aspose compressed document (1_compressed (ImageQuality 10).pdf) has size of 10.044.083 bytes

Test documents are in BIN/DEBUG folder

Can you please try to figure out why Web tool (by comparing documents) has such a smaller size?

As you can see Web tool document does not have noticeable document quality reduction.

Through experimenting with ImageQuality I noticed that 60 is really border below which images will be noticeable bad. Even better would be to use ImageQuality of 70 but that will anyway increase document size.

Main point is like above written if you can find out why Web tool compressed file is almost 40% smaller.

Btw. I somewhere in forum red that in case when Adobe did compression you noticed that Color Palette? was changed thus document size decreased. Is it here also the case? What else is different?

If you can improve compression that would be excellent for my company case (probably some other customer will have same interest).

Download link is:


Thanks in advance,

Hi Oliver,

Thanks for your inquiry. I am afraid I am unable to download the project, It seems it is removed. Please share it again, so we will test the scenario and will provide you information accordingly.

We are sorry for the inconvenience caused.

Best Regards,
Hi Tilal,

can you try this link:


I jest tested and worked for me.


Hi Oliver,

Thanks for sharing the link again, it worked for me as well. I will look into the issue and will get back to you soon.

Best Regards,

HI Oliver,

Thanks for your patience. I have tested the scenario and noticed the optimization size difference. So I have logged an enhancement ticket PDFNEWNET-39316 in our issue tracking for further investigation and resolution. we will notify you as soon as we resolve the issue.

We are sorry for the inconvenience caused.

Best Regards,

any news here? It is now more than 12 months since issue was reported.
In a meantime you resolved some other PDF issues that I reported after this one :(.


Hi Oliver,

We are sorry for the inconvenience. I am afraid the issue is still not pending for investigation due to other high priority tasks. However, we have again requested our team for ETA and will notify you as soon as some update is available.

Thanks for your patience and cooperation.

Best Regards,

Hi Oliver,

Thanks for your patience. We have a good news for you, we have implemented two new properties in OptimizationOption class, RemovePrivateInfo and MaxResolution in December 2016 release of Aspose.Pdf for .NET i.e. 16.12.0. These properties will further improve the PDF document optimization feature. With new release you can use these properties as following.



LinkDuplcateStreams = true,

RemoveUnusedObjects = true,

RemoveUnusedStreams = true,

CompressImages = true,

RemovePrivateInfo = true,

ImageQuality = 50,

MaxResoultion = 75


Best Regards,

The issues you have found earlier (filed as PDFNEWNET-39316) have been fixed in Aspose.Pdf for .NET 16.12.0.

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