DNG supports (lossy) JPEG compression starting with version 1.4.
Building the DNG SDK with JPEG support requires libjpeg.

For your convenience, a copy of libjpeg is included in this package.
You may also obtain libjpeg directly from:

http://www.ijg.org/files/jpegsrc.v9c.tar.gz

or

http://www.ijg.org/files/jpegsr9c.zip

Move the contents of the "jpeg-9c" folder into the "libjpeg" folder.

The DNG SDK includes a pre-built "jconfig.h" which works on macOS and
Windows.
