PDF Compression Types

[joleneb38156190]

Is there a tool that can be used to view the compression type used in a pdf file?  Thank you.

[Dov Isaacs · Accepted solution]

There is no such thing as the compression type used in a PDF file. For different aspects of a PDF file, there are different forms of compression used. Beginning with PDF 1.5, object streams within the PDF file are compressed using lossless Flate (ZIP) compression. In terms of raster images, each image may be compressed differently in terms of type, degree, etc.

Text and vector objects as well as other PDF commands are stored in the compressed object streams, per above.

To determine the compression used for a particular raster image, in Acrobat Pro DC, go to Production Tools and select Output Preview. Within the Output Preview windows, Go to Preview and select Object Inspector. Move your cursor to the object you wish information about (including compression type) and click. The information regarding all objects under the cursor will appear in the window of the dialog. You will be surprised how useful this tool is!

          - Dov

[joleneb38156190]

Thank you.