[libcamera-devel] [PATCH] utils: rkisp1: gen-csc-table: Specify coefficients with full precision
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Mon Aug 29 10:47:46 CEST 2022
The Rec01, Rec709, Rec2020 and SMTPE 240M standards specify the Cb and
Cr coefficients of the RGB to Y'CbCr conversion matrix using a quotient
of two values. Use the exact same formulas instead of hardcoding the
division results with a lower precision.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
utils/rkisp1/gen-csc-table.py | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/utils/rkisp1/gen-csc-table.py b/utils/rkisp1/gen-csc-table.py
index ca0187ec24c6..2fb702746421 100755
--- a/utils/rkisp1/gen-csc-table.py
+++ b/utils/rkisp1/gen-csc-table.py
@@ -12,24 +12,24 @@ import sys
encodings = {
'rec601': [
- [ 0.2990, 0.5870, 0.1140 ],
- [ -0.1687, -0.3313, 0.5 ],
- [ 0.5, -0.4187, -0.0813 ]
+ [ 0.299, 0.587, 0.114 ],
+ [ -0.299 / 1.772, -0.587 / 1.772, 0.886 / 1.772 ],
+ [ 0.701 / 1.402, -0.587 / 1.402, -0.114 / 1.402 ]
],
'rec709': [
- [ 0.2126, 0.7152, 0.0722 ],
- [ -0.1146, -0.3854, 0.5 ],
- [ 0.5, -0.4542, -0.0458 ]
+ [ 0.2126, 0.7152, 0.0722 ],
+ [ -0.2126 / 1.8556, -0.7152 / 1.8556, 0.9278 / 1.8556 ],
+ [ 0.7874 / 1.5748, -0.7152 / 1.5748, -0.0722 / 1.5748 ]
],
'rec2020': [
- [ 0.2627, 0.6780, 0.0593 ],
- [ -0.1396, -0.3604, 0.5 ],
- [ 0.5, -0.4598, -0.0402 ]
+ [ 0.2627, 0.6780, 0.0593 ],
+ [ -0.2627 / 1.8814, -0.6780 / 1.8814, 0.9407 / 1.8814 ],
+ [ 0.7373 / 1.4746, -0.6780 / 1.4746, -0.0593 / 1.4746 ],
],
'smpte240m': [
- [ 0.2122, 0.7013, 0.0865 ],
- [ -0.1161, -0.3839, 0.5 ],
- [ 0.5, -0.4451, -0.0549 ]
+ [ 0.2122, 0.7013, 0.0865 ],
+ [ -0.2122 / 1.8270, -0.7013 / 1.8270, 0.9135 / 1.8270 ],
+ [ 0.7878 / 1.5756, -0.7013 / 1.5756, -0.0865 / 1.5756 ],
],
}
base-commit: 3fad116f89e0d3497567043cbf6d8c49f1c102db
--
Regards,
Laurent Pinchart
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