From e91f6c384f837f8cf685c9d32355ea1b3b77d5ec Mon Sep 17 00:00:00 2001
From: Stefan Klug <stefan.klug@ideasonboard.com>
Date: Fri, 14 Jun 2024 12:35:50 +0200
Subject: libtuning: lsc: rkisp1: Do not calculate ratios to green

The current LSC algorithm for the rkisp1 just forwards the LSC tables to
the hardware, so absolute factors are needed and not ratios compared to
green. Therefore every channel needs to be calculated independently.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
---
 utils/tuning/libtuning/modules/lsc/rkisp1.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'utils/tuning')

diff --git a/utils/tuning/libtuning/modules/lsc/rkisp1.py b/utils/tuning/libtuning/modules/lsc/rkisp1.py
index 512233ae..c02b2306 100644
--- a/utils/tuning/libtuning/modules/lsc/rkisp1.py
+++ b/utils/tuning/libtuning/modules/lsc/rkisp1.py
@@ -33,13 +33,13 @@ class LSCRkISP1(LSC):
     #         table, flattened array of (blue's) green calibration table
 
     def _do_single_lsc(self, image: lt.Image):
-        cgr, gr = self._lsc_single_channel(image.channels[lt.Color.GR], image)
-        cgb, gb = self._lsc_single_channel(image.channels[lt.Color.GB], image)
-
-        # \todo Should these ratio against the average of both greens or just
-        # each green like we've done here?
-        cr, _ = self._lsc_single_channel(image.channels[lt.Color.R], image, gr)
-        cb, _ = self._lsc_single_channel(image.channels[lt.Color.B], image, gb)
+        # Perform LSC on each colour channel independently. A future enhancement
+        # worth investigating would be splitting the luminance and chrominance
+        # LSC as done by Raspberry Pi.
+        cgr, _ = self._lsc_single_channel(image.channels[lt.Color.GR], image)
+        cgb, _ = self._lsc_single_channel(image.channels[lt.Color.GB], image)
+        cr, _ = self._lsc_single_channel(image.channels[lt.Color.R], image)
+        cb, _ = self._lsc_single_channel(image.channels[lt.Color.B], image)
 
         return image.color, cr.flatten(), cb.flatten(), cgr.flatten(), cgb.flatten()
 
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