Re: Color faxes have incorrect colors

Thanks for the detailed answer. See further questions inlined.

On Wed, Feb 27, 2019 at 09:31:51AM -0800, Lee Howard wrote:
> Color fax uses ITULAB color space.  So, the received TIFFs that you're
> getting are using ITULAB color space.  Unfortunately, most TIFF and JPEG
> viewers don't know how to properly handle ITULAB color space, and so
> they mess it up.

So are there any TIFF to PDF converters that would handle this properly?

> 
> Years and years ago when color fax reception support was introduced into
> HylaFAX (2005) the plan/thought was to get libtiff and libjpeg
> enhanced/modified to compensate for that.  There was a patch circulated,
> but it never made it into libjpeg.  And, ultimately the plan/thought was
> modified to just change the JPEG data colorspace before writing it into
> the TIFF for portability reasons, but that was after HylaFAX+ came into
> existence.  So, the v6.0.6 release is still using the ITULAB colorspace
> in its received color faxes.
> 
> In HylaFAX+ v5.4.0 (2009) it began using LittleCMS to modify the JPEG
> data colorspace before writing it into the TIFF.  Also, color fax
> sending support was added.
> 
Sounds like I might need to switch to HylaFax+. Why is it not in Debian 
and Mint repositories? Does this mean it must be installed from source? 

> To send a color fax with HylaFAX+ you can use the sendfax -O "usecolor"
> option.  (See 'man sendfax'.)  You will probably need to be using a
> Class 1/1.0 modem (unless you have one of a few Class 2.0/2.1 modems
> that support color) and have "Class1ColorJPEGSupport" set to "true" or
> "yes" in your modem config file.
> 
> Thanks,
> 
> Lee.
Thanks Lee.
--
Jason 

> On 02/26/2019 06:26 PM, Jason wrote:
> > Hi,
> >
> > On Linux Mint 18.1 using the version of HylaFax that is packaged with 
> > the distribution (6.0.6). Using a ZOOM 3095 56K V.92/V.90 USB modem.
> >
> > When I turn on color fax reception with (in 
> > /var/spool/hylafax/etc/config.ttyACM0):
> >
> > 	Class1ColorJPEGSupport: Yes
> >
> > color faxes are received but have a badly messed up color scheme, the 
> > most prominent feature being a bright orange color across the whole page 
> > background and wherever something ought to be white. Do I have the 
> > wrong setting or what might be the problem? 
> >
> > Another question I have is how do I *send* a color fax?
> >
> > Thank you.
> 
> 
> 
> 
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