libtuning: Add initial AWB module

This AWB module uses the awb function from Raspberry Pi to calculate the
needed white balance gains per colour temperature. It stores these gains
in the tuning file.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

utils/tuning/libtuning/modules/awb/awb.py

@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2024, Ideas On Board
+
+import logging
+
+from ..module import Module
+
+from libtuning.ctt_awb import awb
+import numpy as np
+
+logger = logging.getLogger(__name__)
+
+
+class AWB(Module):
+    type = 'awb'
+    hr_name = 'AWB (Base)'
+    out_name = 'GenericAWB'
+
+    def __init__(self, *, debug: list):
+        super().__init__()
+
+        self.debug = debug
+
+    def do_calculation(self, images):
+        logger.info('Starting AWB calculation')
+
+        imgs = [img for img in images if img.macbeth is not None]
+
+        gains, _, _ = awb(imgs, None, None, False)
+        gains = np.reshape(gains, (-1, 3))
+
+        return [{
+                    'ct': int(v[0]),
+                    'gains': [float(1.0 / v[1]), float(1.0 / v[2])]
+                } for v in gains]