jdeps needs to support something like javac -release option. Before it's supported, it should provide an interim solution to flag any JDK internal APIs that may be removed/renamed in JDK 9.

$ jdk8u/bin/jdeps -jdkinternals batik-all-1.8.jar
JDK Internal API Suggested Replacement
---------------- ---------------------
com.sun.image.codec.jpeg.JPEGCodec Use javax.imageio @since 1.4
com.sun.image.codec.jpeg.JPEGDecodeParam Use javax.imageio @since 1.4
com.sun.image.codec.jpeg.JPEGEncodeParam Use javax.imageio @since 1.4
com.sun.image.codec.jpeg.JPEGImageDecoder Use javax.imageio @since 1.4
com.sun.image.codec.jpeg.JPEGImageEncoder Use javax.imageio @since 1.4
com.sun.image.codec.jpeg.JPEGQTable Use javax.imageio @since 1.4

com.sun.image.codec.jpeg has been removed from JDK 9. jdk9/bin/jdeps does not flag references to com.sun.image.codec.jpeg as internal API since it doesn't find it from the system image.