Xnview image viewer and converter supports many, even less known and long forgotten image file types, so it is your best bet for exporting old JBG images (JBIG-1) as PDF documents.
Convert Image JBIG 1-bit raster image to Adobe Portable document format.
We have found one software suitable in our database for this conversion.
Multiplatform software - convert jbg to pdf on any platform
A free (for non-commercial purposes) powerful cross-platform media browser, viewer and converter. Compatible with more than 500 formats and also supports export to 70 different file formats. It works on Windows, Linux and macOS (OS X).
Convert from jbg file
|Yes, XnView MP supports jbg file conversion as a source file type.||No||No||No||No||No||No||No|
to pdf file
|Yes, XnView MP supports pdf file conversion as a target file type.||No||No||No||No||No||No||No|
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.