progressive to baseline jpeg

TGB_72 · Post by **TGB_72** » Thu Feb 22, 2007 3:51 am

Hi,

I've many pictures that were compressed as "progressive jpeg" but my pioneer dvd player can't play them, only can play baseline jpeg pictures, so I would like to know if it's possible a loosless jpeg conversion from progressive to baseline with xnview.

Thanks in advance for any help.

Post by **XnTriq** » Thu Feb 22, 2007 5:20 am

TGB_72, please stand by for a response from foxyshadis. In the meantime, here's what I've got:

JPEG image compression FAQ: [url=http://www.faqs.org/faqs/jpeg-faq/part1/section-11.html]What is progressive JPEG?[/url] wrote:It is possible to convert between baseline and progressive representations of an image without any quality loss. (But specialized software is needed to do this; conversion by decompressing and recompressing is *not* lossless, due to roundoff errors.)

OpenSourceInfo.org: Man Pages » [url=http://www.opensourceinfo.org/index.php/man_pages/cjpeg]cjpeg[/url] wrote:-baseline
Force baseline-compatible quantization tables to be generated. This clamps quantization values to 8 bits even at low quality settings. (This switch is poorly named, since it does not ensure that the output is actually baseline JPEG. For example, you can use -baseline and -progressive together.)

The Independent JPEG Group's JPEG software: jpeg6b32.zip (199 KB)

TGB_72 · Post by **TGB_72** » Thu Feb 22, 2007 5:34 am

Thanks for reply XnTriq, since I couldn't find loosless progressive=>baseline conversion in Xnview I tried with Irfanfiew (options=>jpg loosless operations=>check optimizing & cleaning options only) and it works perfect, now the pictures play perfectly in my dvd player. I hope that Xnview add this feature in a near future (of course if it was not already added and I couldn't see it).

marsh · Post by **marsh** » Thu Feb 22, 2007 6:04 am

TGB_72 wrote:Thanks for reply XnTriq, since I couldn't find loosless progressive=>baseline conversion in Xnview I tried with Irfanfiew (options=>jpg loosless operations=>check optimizing & cleaning options only) and it works perfect, now the pictures play perfectly in my dvd player. I hope that Xnview add this feature in a near future (of course if it was not already added and I couldn't see it).

Have you tried: Browser Menu... Edit>Metadata>Clean... ?
It improves Firefox's loading speed of a sample 'progressive' jpg which I created.

TGB_72 · Post by **TGB_72** » Thu Feb 22, 2007 6:32 am

thanks marsh, it worked great but I couldn't find the way to do it in batch mode like I did it with irfanview, do you know if it's possible?

marsh · Post by **marsh** » Thu Feb 22, 2007 6:37 am

TGB_72 wrote:thanks marsh, it worked great but I couldn't find the way to do it in batch mode like I did it with irfanview, do you know if it's possible?

Clean works on multiple selected files also. It doesn't currently operate in batch convert/nconvert because it alters directly the original file.

TGB_72 · Post by **TGB_72** » Thu Feb 22, 2007 6:41 am

strange then, I've selected 112 pictures and clean option is greyed/unavailable

TGB_72 · Post by **TGB_72** » Thu Feb 22, 2007 6:49 am

it was because among all those files I had selected 1 bmp, nowit works perfect, thanks for your help.

foxyshadis · Post by **foxyshadis** » Thu Feb 22, 2007 11:16 am

XnTriq wrote:TGB_72, please stand by for a response from foxyshadis. In the meantime, here's what I've got:

haha! cjpeg is exactly what I would have pointed to, though, didn't know irfanview had that option. Good to know, and I totally agree that a 'make progressive/non-progressive' would fit perfectly in the lossless transformation box.