NetPBM sillyness

jetheller · Post by **jetheller** » Fri Apr 15, 2005 7:25 pm

So I install netpbm and tell ZM that it is there. I notice a huge drop in bandwidth usage and the images become much more fuzzy. That's fine, and what I expected. But then I look at the actual images being stored to disk and see the netpbm option isn't just sending me low quality images, it is storing them to disk. For some reason, turning on netpbm turned my "store jpegs at 95% quality" to storing them at around 10% (eyeballing it). Is this what is supposed to happen, or do I have something misconfigured?

For the record I have
saved event files at 95
streamed 'live' images at 10

FTPing a jpeg over with netpbm turned off, I get a 95 quality jpeg.
FTPing a jpeg over with netpbm turned on, I get a 10 quality jpeg.

No biggie, just thought it was odd.

jetheller · Post by **jetheller** » Fri Apr 15, 2005 8:00 pm

On further messing around, I find I cannot resolve the problem. My normal 95% compressed jpegs are taking about 38K of space. Now that I've turned on netpbm (and then turned it off), I can't create jpegs of anymore quality than 3K, even though I've turned up the quality of files saved to disk to 100. It appears that turning on netpbm has permanently set my 'save to disk' setting about about 10% jpeg.

I've tried changing settings hoping this would reset something, but to no avail. And let me tell you, a 3k 320X240 jpg is a BLURRY image

jetheller · Post by **jetheller** » Sat Apr 16, 2005 3:40 pm

Okay, nevermind. The problem appeared to be a lack of patience. After turning off netpbm and messing with the jpg quality settings, the jpg quality settings eventually started having an effect. It took about an hour, but now the jpg quality settings have an instant effect on restart.

I'm not even sure I understand exactly what netpbm is supposed to do. It would appear the functionality of netpbm is overlapping with turning the jpg stream quality down. I guess I'll have ot experiment more

Post by **zoneminder** » Mon Apr 18, 2005 4:11 pm

The Netpbm tools are really only used for creating thumbnails etc. The actual recorded images are created by ZM using libjpeg. Any changes to the JPEG quality you set in ZM will take effect next time you restart ZM or the individual processes.

Phil