2001.10.04 22:42 "Re: OJPEG & Wang Images (long)", by Tim Bell
Hi Scott (and everyone else),
During the past year or so, there have been frequent queries to this discussion group about the TIFF Library's capacity to manipulate files created according to the now-deprecated TIFF Version 6 method of encapsulating JPEG-compressed images.
I'm an old UNIX hacker who knows little about world of Wintel software (I wrote "tif_ojpeg.c" to improve the popular "xv(1)" viewer for my local users), but I became curious about where those grotty Wang TIFF files are coming from, so I asked a coworker for a "guided tour" of his PCs in order to find information about this software: who wrote it, and why any sensible person would use it.
I find this quite ironic! A year ago (to the day!), I sent an email to this list on a related topic:
On Thu 05 Oct 2000 at 11:20:44 +1100, Tim Bell wrote:
> We've got an HP 9100C Digital Sender (network connected scanner) and
> it seems to be producing Old-style JPEG TIFFs, which libtiff says it
> can't read.
Despite an in-depth email discussion with HP engineers (via an HP support person, which may have added some noise to the exchange ;), it appeared that HP's position was that they weren't going to change the format of TIFFs produced by the Digital Sender.
The appearance of OJPEG support in libtiff (thanks to Scott Marovich) was quite unexpected, and caused me to wonder if this was HP's roundabout way of addressing the problem we had. The fact that you [Scott] seem unaware of HP's own OJPEG-producing product suggests that this isn't the case.
In any case, I built libtiff 3.5.7beta yesterday, and tested it on an image produced by the HP 9100C. xv gave a couple of "Huffman table too big.." errors, and then died. I just now tried Imagemagick, which gave the same errors and then correctly displayed the (very large) image. So it seems to work. (I'll do another test today with xv and a smaller image.) Many thanks to Scott Marovich for his hard work, and for sharing it with us.
However, I still believe that the proper solution to this problem is to have HP supply us with updated firmware for the 9100C which doesn't create OJPEG tiffs. Scott, I wonder if you would be in a position to bring this up with the appropriate people in HP, seeing that you understand the implications of creating OJPEG tiffs? It may also be worth mentioning it to Bruce Perens (Open Source Strategist for HP) -- although now that there is open source support for reading OJPEG files, he would have less of a case to make.
Thanks again Scott,
Tim Bell - email@example.com - System Administrator & Programmer
Trinity College, Royal Parade, Parkville, Victoria, 3052, Australia