ipa: ipu3: Add support for IPU3 AWB algorithm

The IPA will locally modify the parameters before they are passed down
to the ImgU. Use a local parameter object to give a reference to those
algorithms.

Inherit from the Algorithm class to implement basic AWB functions.

The configure() call will set exposure and gain to their minimum value,
so while AGC is not there, the frames will be dark.

Once AWB is done, a color temperature is estimated and a default CCM matrix
will be used (yet to be tuned).
Implement a basic "grey-world" AWB algorithm just for demonstration purpose.

The BDS output size is passed by the pipeline handler to the IPA.
The best grid is then calculated to maximize the number of pixels taken
into account in each cells.

As commented in the source code, it can be improved, as it has (at least)
one limitation: if a cell is big (say 128 pixels wide) and indicated as
saturated, it won't be taken into account at all.
Maybe is it possible to have a smaller one, at the cost of a few pixels
to lose, in which case we can center the grid using the x_start and
y_start parameters.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Tested-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/ipa/ipu3/meson.build b/src/ipa/ipu3/meson.build
index a241f617..1040698e 100644
--- a/src/ipa/ipu3/meson.build
+++ b/src/ipa/ipu3/meson.build
@@ -2,8 +2,13 @@
 
 ipa_name = 'ipa_ipu3'
 
+ipu3_ipa_sources = files([
+    'ipu3.cpp',
+    'ipu3_awb.cpp',
+])
+
 mod = shared_module(ipa_name,
-                    ['ipu3.cpp', libcamera_generated_ipa_headers],
+                    [ipu3_ipa_sources, libcamera_generated_ipa_headers],
                     name_prefix : '',
                     include_directories : [ipa_includes, libipa_includes],
                     dependencies : libcamera_dep,