From 6e0e22d2ff65be2dc4d1d7a52726f9d5ace55d45 Mon Sep 17 00:00:00 2001 From: =?utf8?q?=C3=98yvind=20Kol=C3=A5s?= Date: Sun, 16 Nov 2014 03:11:36 +0000 Subject: [PATCH] roadmap: make statement about tentativeness more explicit also add comment about significance of rounding errors relative to sensor/CCD precision. --- docs/roadmap.txt | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/docs/roadmap.txt b/docs/roadmap.txt index db3a4f7..10b9cf6 100644 --- a/docs/roadmap.txt +++ b/docs/roadmap.txt @@ -74,6 +74,9 @@ specific) data types in babl - or have new ones registered. Limitations/roadmap: ==================== +Note that this roadmap doesn't document a final state of things, but a +direction that allows finer control over how things work. + Babl currently only supports formats using the sRGB primaries, quite a few editing operations including gamma adjustments and multiply compositing relies on the chromaticities of the space used, permitting at least linear formats @@ -94,7 +97,8 @@ void babl_define_named_rgb_space ( To keep existing code relying on existing behavior working, such named spaces would not be addressed through the same babl-format names as the existing formats. Instead a space registered for the name "sensor" would be addressed -as babl_format(babl, "wide:RGBA float") or babl_format(babl, "sensor:RaGaBaA half") etc. +as babl_format(babl, "wide:RGBA float") or babl_format(babl, "sensor:RaGaBaA +half") etc. Babl would also be extended with light-weight sub-babl contexts; so that different documents or parts of a workflow have their own name space within @@ -109,7 +113,7 @@ For questions, please join #gegl on the GIMP/GNOME irc network. -- To further pencil out what the situation would be at the end of this -refactoring, focusing only on the formats and what they would mean. +(incomplete) roadmap, focusing only on the formats and what they would mean. For formats where all components have the same type, the type is suffixed at the end, conversions within a given model but different types only needs to do @@ -171,4 +175,11 @@ Once a format has been resolved using babl_format(babl, "bar:RGBA float") the returned pointer would refer to the babl context that looked up "bar"'s definition of bar. This makes it easy to define specific names, like camera / chromaticicities / compositing / target and other similar concerns per -document; with the corresponding space configuration loaded into each. +document; with the corresponding space configuration loaded into each. And +allows rigging up a situation where the user has control over the RGB space +used for chromaticity dependent operations. + +Floating point rounding errors are not a significant issue; since single +precision floating point which is the intermediate formats mostly used by GEGL +have 24bits significand precision - which is much higher than the bitdepth of +most imaging sensors. -- 2.30.2