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Here's the first paragraph: A well-known image format using .jpg, .jpeg, or .jpe extension. JPG does not store projection information. If a JPG image file is accompanied by a JPGW world file, Manifold will use the information in the world file, if possible, to assign an initial coordinate system. JPG files with correctly formed JPGW world files are rare: most GIS users many years ago switched to TIFF or GeoTIFF as a GIS image format. When exporting, .prj and .mapmeta files are written. See the Exporting topic.
So why are you still asking, like in your other post, if Manifold can read a .jpg file accompanied by a .jpgw file? Can either manifold 8 or 9 open .Jpg with associated .jpgw that is spatially orientated in the right part of the world? and if so how?
Don't double-post the same question in multiple threads. If you don't understand the sentence "If a JPG image file is accompanied by a JPGW world file, Manifold will use the information in the world file, if possible, to assign an initial coordinate system" then post something like "I don't understand what this means..." Reading the Exporting topic there is explicit discussion of what Manifold exports in the section captioned "Exporting Coordinate Systems / Projections". There's also explicit discussion of what Manifold writes when exporting JPEG, as in JPG, JPEG, JPE - A well-known image format using .jpg, .jpeg, or .jpe extension. .prj and .mapmeta files are written.
If you don't understand something in that topic, state what it is you don't understand. Then people can answer it. If you write something like "I read everything and I don't understand it," well, most people will think you skimmed over topics instead of reading them because the answers to your questions are right there in black and white, like in the example of the sentence I gave above. If, on the contrary, you quote a sentence you don't understand then people can explain it to you. I get the feeling you don't understand the basics of what worldfiles (.jpgw) are and how they differ from .prj, or perhaps you're unfamiliar with projections and coordinate systems. If you don't reproject an image you can usually simply recycle the .jpgw. But none of that should be necessary for exporting something from 9 to 8. An even more sensible approach is to save the file as a GeoTIFF and then read it in 8. Why mess around with a format like .jpg which is not spatially aware when you want to work with projected data? Using a spatially aware format like GeoTIFF makes everything pretty much one-click automatic, while if you insist on using non-spatial formats to store spatial data you have to acquire a lot of expertise in obsolete, Rube Goldberg approaches like world files or even prj. If you must do that, well, OK, you can do it in Manifold, but you have to learn a lot more to get it right than simply using a modern, spatial format.
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