No conversion appears to take place and the save goes through, so if you open a file as one format and save as another you end up with identical data but different extensions.
I have a fix for this locally, along with 381774 and 381830. Just need a bit more testing.
Git commit b4b9021616edcfb1e6bfd084c5567f69da7668fa by Victor Wåhlström. Committed on 14/07/2017 at 19:27. Pushed by victorw into branch 'master'. Add support for non-square heightmap import/export and various related improvements/bugfixes * Support for non-square heightmap files (.r8, .r16) * New heightmap import/export dialog * Fixed issue where imported heightmap is "transposed" * Fixed issue where saving an r16 heightmap file as r8 or vice versa only changes the extension Related: bug 381774, bug 381830 Differential Revision: https://phabricator.kde.org/D6460 M +10 -0 libs/ui/kis_config.cc M +3 -0 libs/ui/kis_config.h M +4 -0 plugins/impex/heightmap/CMakeLists.txt M +39 -44 plugins/impex/heightmap/kis_heightmap_export.cpp M +1 -17 plugins/impex/heightmap/kis_heightmap_export.h M +50 -35 plugins/impex/heightmap/kis_heightmap_import.cpp M +1 -1 plugins/impex/heightmap/kis_heightmap_import.h A +230 -0 plugins/impex/heightmap/kis_wdg_options_heightmap.cpp [License: LGPL (v2.1+)] A +52 -0 plugins/impex/heightmap/kis_wdg_options_heightmap.h [License: LGPL (v2.1+)] M +170 -59 plugins/impex/heightmap/kis_wdg_options_heightmap.ui A +10 -0 plugins/impex/heightmap/tests/CMakeLists.txt A +- -- plugins/impex/heightmap/tests/data/results/test_512x256.r16.png A +- -- plugins/impex/heightmap/tests/data/results/test_512x256.r8.png A +- -- plugins/impex/heightmap/tests/data/results/test_512x512.r16.png A +- -- plugins/impex/heightmap/tests/data/results/test_512x512.r8.png A +- -- plugins/impex/heightmap/tests/data/sources/test_512x256.r16 A +1 -0 plugins/impex/heightmap/tests/data/sources/test_512x256.r8 A +- -- plugins/impex/heightmap/tests/data/sources/test_512x512.r16 A +1 -0 plugins/impex/heightmap/tests/data/sources/test_512x512.r8 A +36 -0 plugins/impex/heightmap/tests/kis_heightmap_test.cpp [License: GPL (v2+)] A +31 -0 plugins/impex/heightmap/tests/kis_heightmap_test.h [License: GPL (v2+)] https://commits.kde.org/krita/b4b9021616edcfb1e6bfd084c5567f69da7668fa