2008.12.16 22:49 "Re: [Tiff] Converting JPEG to TIFF to use EFAX", by Lee Howard

Rick Cone,Secure Payment Systems wrote:

I have a several JPEG images that I want to send as a fax using efax (efix).

Seems I need to convert the JPEG's to TIFF.

Does anybody know of a good convert tool, or perhaps a better method when using efax?

efax doesn't support color faxing, and so I assume, therefore, that you're taking some kind of (color) JPEG and turning it into monochrome "fax" (MH, MR, MMR) data in a TIFF.

This will, therefore, involve some kind of dithering process in order to change the colors into a representative pattern of black dots on a white background.

There is a "jpeg2ps" tool out there by Thomas Merz (I use 1.9). You can then take that Postscript output and feed it through Ghostscript to one of its TIFF drivers to create a TIFF.

However, I find the default dithering in Ghostscript to be poor. You can improve it by involving Ghostscript's stocht.ps to do the dithering, however, my preferred method is to involve libtiff's own tiff2bw and tiffdither tools for Floyd-Steinberg dithering.

If you're not needing to automate it, I certainly would advise using a GUI tool and visually inspect the dithering before faxing.

Thanks,

Lee.