Compare with the discrete labelmaps of [Rosenberger09] & [Lockerman16]

Note that in [Lockerman16] the discrete labelmaps contain multiple scales,
which are indicated as C4, C3, C2 and C1 below. For more information, please refer to their paper.

exemplar	Our progression map	[Rosenberger09]	[Lockerman16] - C4	[Lockerman16] - C3	[Lockerman16] - C2	[Lockerman16] - C1

Further comparison on controlled synthesis between our continuous progression map and discrete label map of [Lockerman16].
Note that for [Lockerman16], C4 label maps are used for the first two exemplars and C3 for the third one.
And when designing the target discrete maps, we force the propotions of different labels be the same as the source label maps as far as possible.

1.jpg	bump	invbump	refined_bump	refined_invbump
[Lockerman16]	bump_discrete	invbump_discrete	refined_bump_discrete	refined_invbump_discrete
2.jpg	bump	invbump	refined_bump	refined_invbump
[Lockerman16]	bump_discrete	invbump_discrete	refined_bump_discrete	refined_invbump_discrete
3.jpg	bump	invbump	refined_bump	refined_invbump
[Lockerman16]	bump_discrete	invbump_discrete	refined_bump_discrete	refined_invbump_discrete