Free Seattle FilmWorks/PhotoWorks image converter

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Last update: 1999-08-29

Free Seattle FilmWorks image converter

SFW2JPG.EXE is a small MS-DOS utility that will convert Seattle FilmWorks image files to plain vanilla JPEGs without reducing the already limited quality. Usage is straightforward. Bring up a MS-DOS box, go to your SFWs and type:

SFW2JPG *.SFW

Your original SFWs will not be overwritten. The program can also convert a single file or convert files between drives etc. If SFW2JPG.EXE is launched without parameters, it will display a brief help text.

Unfortunately all the resulting pictures has the wrong orientation. Instead of having this problem with portraits only, all the pictures will need a vertical flip and sometimes a rotate. There are other softwares out there which can fix this without quality reduction. For example Holger Jungk's PIE (Pic Info Extractor).

Background

During two years I used to process film at a lab which used the Seattle FilmWorks system and returned 640x437 images on diskette. I no longer use them, but I had this collection of ~200 pictures in their proprietary file format. Even though the picture quality was pretty poor, I still wanted to review the images without also diluting my hard disk with their PhotoWorks® software.

It's possible to open the images with PhotoWorks® and save them as JPEGs, but that is not attractive because the JPEG compression will reduce quality.

The size of SFWs are about the same as JPEGs, so I suspected the compression to be similar. After learning more about JPEGs (by reading Tom Lanes JPEG FAQ) I started to reverse engineer the SFW files with the MS-DOS debugger. I found the SFWs to be nothing but mangled JPEGs. With a little hint from Ed Hamrick (the author of VuePrint) I managed to collect the remaining info that was needed to write SFW2JPG.EXE

Enjoy! Bengt Cyrén

It doesn't work!

Well, it did for me. All my SFWs from 1996 and 1997 has been successfully converted by the program. I've been told that SFW has changed their file format a number of times. My pics are pretty old.

Anyway, if you're interested in taking up the work where I left, feel free to do whatever you like with the source:

   sfw2jpg.h
   sfw2jpg.c
   main.c

If you're interested in some weekend hacking, but doesn't have any SFWs around, you can use the sample below.

amanda.sfw (29 kB)