macintosh packbits compression

581 views7 repliesLast post: 2/16/2004
I have a .jpg file that I am unable to open on the pc. Irfanviewer reports its compression as Macintosh Packbits. It is viewable in InDesign 2 but Photoshop and ImageReady can't open it.

I can have the mac user resave it but is there any way I can use or unpack it on the pc? Any help appreciated.

Bob
#1
JPEG files can't use any compression other than JPEG (it does have some optioins, but PackBits isn't one of them).

I suspect that this is not a JPEG file, and it somehow got mislabeled.
#2
Thanks, it sounded strange that a jpg would use another compression to me. Anyhow, you are right. Named it a tif and it works!! Bob

wrote:

JPEG files can't use any compression other than JPEG (it does have some optioins, but PackBits isn't one of them).

I suspect that this is not a JPEG file, and it somehow got mislabeled.
#3
Packbits is so old that you can only get them from a time machine. I actually did receive a packbits file from Europe a few years ago and read it in Graphic Converter. A black and white architectural drawing from one of those original macs.
#4
I'm having a problem opening some packbit-compressed TIFF files in Photoshop CS for PC.

I could not open a file in Photoshop (the error message was "Could not complete your request because of a program error"), but I can open the same file using Paint Shop Pro. When I re-save the file in Paint Shop Pro, it gets about 4MB bigger in size, and then it will open in Photoshop.

I have many files that are packbit compressed, and would like to avoid the open/re-save step in Paint Shop. Any help is appreciated.

Steve.
#5
Steve - what version of Photoshop? Photoshop should always handle PackBits compression without any problems.

Also, if this was 7.0 or CS, it would help if I could get some sample files that gave an error.
#6
Hi Chris,
I'm using Photoshop CS. The error pops up after a second or two of processing.

The file is a scanned map, and is quite big (about 176 MB). Can I put it on an FTP server and e-mail you the address?

Thanks,
Steve.
#7
Steve - sure. Email me at
#8