CompuServe Thread

#JPEG question

10 messages in this thread
#31107From: Leslie T. BartiromoDec 3, 1991 6:53 PM
Can you tell me how transportable JPEG is across computer formats? I have a BBS loaded with Amiga images and I was wondering if Mac and IBM users could easily convert JPEG images. I'd use GIF format but the JPEG files are MUCH smaller. Thanks.
#31147From: John GagerDec 4, 1991 12:58 AM
Leslie, there are a couple of JPEG conversion programs for the IBM and Mac computers. For IBM, there is a program called "Image Alchemy", and I believe the latest version is 1.4. I know that ImageMaster can convert JPEG pictures saved with Alchemy, so you can probably be safe in assuming the reverse is true. I'm not sure about images saved with ADPro 2.0, because I haven't received my update yet (HINT HINT Perry 8^) . The Mac seems to be a different story. Seems like everyone wants to use their own proprietory JPEG format, so I'm not sure if the Mac programs can read the standard JPEG files or not. Perry will probably be able to give you some more information. John – K7KB (via Whap!)
#31172From: Leslie T. BartiromoDec 4, 1991 5:56 PM
Thanks for the information. (I didn't get ADPro 2.0 yet either. HINT HINT from me too!<g>) I am wondering if I should post pictures on my BBS in JPEG.
#31201From: John GagerDec 5, 1991 2:36 AM
You probably can post the pictures in JPEG format, but I wouldn't expect a lot of downloads from your BBS just yet. JPEG is still in the development stage and not a lot of IBM'ers or Mac'ers have JPEG conversion software. Give it a try and see what kind of response you get. John – K7KB (via Whap!)
#31207From: Leslie T. BartiromoDec 5, 1991 5:09 AM
I kind of thought JPEG was new. Maybe I'll post a question and a download on my board and see what kind of response I get. Thanks.
#31496From: ASDGDec 10, 1991 1:53 PM
First, if your source data is already in an Amiga displayable format (like 4 bit-planes or HAM) then JPEGing will not give you a space savings since it will convert to 24 bit-planes THEN compress. The JPEG file format we use is standard across many platforms including the IBM and MAC. It is called JFIF. pk
#31505From: Leslie T. BartiromoDec 10, 1991 5:13 PM
I was thinking about converting GIF's to 24 bit JPEG for file compression. I'm glad to hear JPEG will transfer across platforms. Do you know the names of the IBM and Mac programs (PD or shareware) that will convert JPEG files to pictures?
#31533From: ASDGDec 11, 1991 6:15 PM
I do not think you will derive the benefit you might expect if your source material is 256 color gif files. After all, JPEG will take the 8 bit-planes the image is already in…convert it out to 24 bit-planes (a three times expansion) and THEN compress it. JPEG is good for 24 bit-plane color images…limited color images may already be compressed pretty well (as compared to compressing them with JPEG). Image Alchemy on the PC, Photoshop on the Mac. And many others. pk
#31549From: J.R. BOOKWALTERDec 11, 1991 10:22 PM
PK, Which version of Photoshop on the Mac supports JPEG? Apparently mine is old, 'cause it doesn't show JPEG as a supported format. Serves me right for not upgrading…. J.R.
#31561From: ASDGDec 12, 1991 12:53 PM
I am not certain of the version…but I do believe PhotoShop now supports the JFIF standard. pk