ADpro JPEG error

[FerociousAmiga]

Trying to convert a JPEG from my Linux FS-UAE ADPro v2.5.1 to IFF (ILBM) and get the following error when loading the JPEG:

Error During Load
Bad JPEG Header
' 'unsupported JPEG SOF
type' '


Does anyone know what is causing this error and how to fix?
Thx in advance.

[Matt_H]

What’s the source of the jpeg? Meaning web, image program, camera, etc.
Best guesses I can come up with are that it either uses some modern jpeg extension that ADPro doesn’t understand (can other vintage tools open it, like ViewTek or an old datatype?) or it’s not actually a jpeg and just has a .jpg file name. Could the file be crunched/corrupt/incomplete?

[fxgogo]

Double check what colour model the jpg. It could be CMYK rather than the more common RGB. That has caught me more than a few times.

[Thomas Richter]

Originally Posted by FerociousAmiga

Trying to convert a JPEG from my Linux FS-UAE ADPro v2.5.1 to IFF (ILBM) and get the following error when loading the JPEG:

Error During Load
Bad JPEG Header
' 'unsupported JPEG SOF
type' '


Does anyone know what is causing this error and how to fix?

SOF is one of the JPEG markers, and it indicates which scan type was used to generate the JPEG file. Unfortunately, there are plenty SOF types, and only a few of them came into practical use. Essentially, 3 are important today, and that's the baseline process, the extended Huffman process, and the progressive mode. (As said, there are plenty more, but those 3 are common). Maybe Adpro only supports baseline and none of the others.


Nothing helps then except loading the JPEG by a more capable program and storing it back, probably enforcing the baseline scan type.


It's not CMYK. That's indicated by an APP-marker, and programs ignoring this marker would just show wrong colors.

[FerociousAmiga]

Thanks Matt_H, fxgogo, Thomas Richter!

It was a web image. Agree, has to be a modern JPEG variation that ADPro can't read properly. I was able to use PPaint 7 to load the JPEG and save it as IFF.