Does a pdf retain file formats?

[Matthew_Lueders@adobeforums.com]

I am not sure this is the right wording for this; but the question is...When writing a pdf out of InDesign does the pdf retain the file formats of the graphics? Meaning do the images in the pdf retain the information and formatting of a tiff, png, jpeg and so on?

[Aandi_Inston@adobeforums.com]

The images remain images, a collection of pixels with colours. They
don't remain TIFF, JPEG, PNG files etc.

Aandi Inston

[Jon Bessant]

But to add to that - they typically get re-compressed using JPEG
compression if they're a typical image (or remain a JPEG if they're told
to retain in the Distiller / Advanced settings) ...

Launch Acrobat - go Advanced / Acrobat Distiller / now when it launches
you can go SETTINGS and EDIT JOB SETTINGS - now examine the IMAGES
section .. it's quite interesting.

However, although it typcially states JPEG (Automatic) Distiller will
auto-sense the incoming content and re-compress accordingly .. i.e.
different compression for a typical image object vs screen shot images
vs continous tone blend ... etc., etc ..

It gets more interesting with direct export from CS2 applications since
they can natively export to DeviceN and NChannel spaces ... another
discussion point ..

Jon