JPG Compression Pipeline - General Discussion and Assistance - CHDK Forum

JPG Compression Pipeline

  • 2 Replies
JPG Compression Pipeline
« on: 15 / January / 2009, 21:09:21 »
Quick question.  Noticed some discussion of the jpg compression routines.  Are these routines something which could be accessed from within CHDK (didn't see hooks in the platform of the main branch)?    Effectively I would like to write multiple JPG images from a single capture.  Can I dump data into the compression pipeline post raw processing?  Can I call them directly if I found the right hook? 

If they dont exist in any branch, it is simply something that has not been found in the firmware meaning I could start hunting or is it that it is located in a coprocessor DSP of some type and not accessible from the main DIGIC chip?

Thanks in advance.



Offline dzsemx

  • ****
  • 302
  • [SX40HS][A650][A630]
Re: JPG Compression Pipeline
« Reply #1 on: 16 / January / 2009, 06:16:58 »
noise reduction and jpeg compression is a huge white spot on the map of the firmware :(


Offline fudgey

  • *****
  • 1705
  • a570is
Re: JPG Compression Pipeline
« Reply #2 on: 16 / January / 2009, 12:41:55 »
Yep, not found but:,2941.msg27691.html#msg27691.

But we do know a way to create multiple JPEGs (with different settings obviously) from the same shot using Canon's RAW->JPEG development process (the RAW develop functionality, available via CHDK file browser and from Lua scripts too,,2646.msg25030.html#msg25030). To automate it you need to write a script.

This may be too slow for your purposes, though.


Related Topics