| Message ID | 20211020154607.180161-5-jeanmichel.hautbois@ideasonboard.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
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| Related | show |
Hi Jean-Michel, Thank you for the patch. On Wed, Oct 20, 2021 at 05:45:58PM +0200, Jean-Michel Hautbois wrote: > When zones are used for the grey world algorithm, they are only > considered if their average green value is at least 32/255 to exclude > zones that are too dark and don't provide relevant colour information > (on the opposite side of the spectrum, saturated regions are excluded by > the ImgU statistics engine). > > The algorithm requires a minimal number of zones that meet this criteria > in order to run. Now that we correct the black level, the 32/255 minimal > value is a bit high and prevents the algorithm for running in low-light > conditions. Lower the value to 16/255 to fix it. > > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> > Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > src/ipa/ipu3/algorithms/awb.cpp | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp > index 62c72cce..1ffb431b 100644 > --- a/src/ipa/ipu3/algorithms/awb.cpp > +++ b/src/ipa/ipu3/algorithms/awb.cpp > @@ -17,7 +17,13 @@ namespace ipa::ipu3::algorithms { > > LOG_DEFINE_CATEGORY(IPU3Awb) > > -static constexpr uint32_t kMinGreenLevelInZone = 32; > +/* > + * When zones are used for the grey world algorithm, they are only considered if > + * their average green value is at least 16/255 to exclude zones that are too * their average green value is at least 16/255 (after black level subtraction) * to exclude zones that are too ... > + * dark and don't provide relevant colour information (on the opposite side of > + * the spectrum, saturated regions are excluded by the ImgU statistics engine). > + */ > +static constexpr uint32_t kMinGreenLevelInZone = 16; > > /* Minimum proportion of cells counted within a zone for it to be relevant */ > static constexpr double kMinRelevantCellsRatio = 0.8;
diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp index 62c72cce..1ffb431b 100644 --- a/src/ipa/ipu3/algorithms/awb.cpp +++ b/src/ipa/ipu3/algorithms/awb.cpp @@ -17,7 +17,13 @@ namespace ipa::ipu3::algorithms { LOG_DEFINE_CATEGORY(IPU3Awb) -static constexpr uint32_t kMinGreenLevelInZone = 32; +/* + * When zones are used for the grey world algorithm, they are only considered if + * their average green value is at least 16/255 to exclude zones that are too + * dark and don't provide relevant colour information (on the opposite side of + * the spectrum, saturated regions are excluded by the ImgU statistics engine). + */ +static constexpr uint32_t kMinGreenLevelInZone = 16; /* Minimum proportion of cells counted within a zone for it to be relevant */ static constexpr double kMinRelevantCellsRatio = 0.8;