Chroma subsampling

[gez]

The current jpeg chroma subsampling method used by the plugin results in smal file sizes, however it is very destructive for images with saturated primaries, specially red. Because of this issue, the plugin becomes almost unusable for certain images that end up showing heavy artifacts despite the quality setting (the artifacts go away when the setting is close to 100, which is ultimately less effective than just saving regular jpgs from the export dialog). I think it would be very useful to have a chroma subsampling setting, or at least a "high quality" checkbox, to switch from the current subsampling setting (4:2:0 I guess) to 4:4:4

[ofnuts]

IMHO it should have the same options as the "advanced options" of the Gimp JPG save/export dialog.

[auris]

Pull requests for this feature are welcome.