Message ID | 20220930190711.13834-1-laurent.pinchart@ideasonboard.com |
---|---|
State | Accepted |
Headers | show |
Series |
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Related | show |
Quoting Laurent Pinchart via libcamera-devel (2022-09-30 20:07:11) > Add a -i/--invert command line argument to invert the YCbCr encoding and > output a YCbCr to RGB matrix. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> > --- > Changes since v1: > > - Fix inverted CSC calculation > - Perform simple rounding for inverted CSC > --- > utils/rkisp1/gen-csc-table.py | 31 +++++++++++++++++++++---------- > 1 file changed, 21 insertions(+), 10 deletions(-) > > diff --git a/utils/rkisp1/gen-csc-table.py b/utils/rkisp1/gen-csc-table.py > index 2fb702746421..f93e7cfacab6 100755 > --- a/utils/rkisp1/gen-csc-table.py > +++ b/utils/rkisp1/gen-csc-table.py > @@ -7,6 +7,7 @@ > > import argparse > import enum > +import numpy as np > import sys > > > @@ -63,9 +64,8 @@ class Quantization(enum.Enum): > LIMITED = 1 > > > -def scale_coeff(coeff, quantization, luma, precision): > - """Scale a coefficient to the output range dictated by the quantization and > - the precision. > +def scale_coeff(coeff, quantization, luma): > + """Scale a coefficient to the output range dictated by the quantization. > > Parameters > ---------- > @@ -75,9 +75,6 @@ def scale_coeff(coeff, quantization, luma, precision): > The quantization, either FULL or LIMITED > luma : bool > True if the coefficient corresponds to a luma value, False otherwise > - precision : int > - The desired precision for the scaled coefficient as a number of > - fractional bits > """ > > # Assume the input range is 8 bits. The output range is set by the > @@ -91,7 +88,7 @@ def scale_coeff(coeff, quantization, luma, precision): > else: > out_range = 240 - 16 > > - return coeff * out_range / in_range * (1 << precision) > + return coeff * out_range / in_range > > > def round_array(values): > @@ -150,6 +147,8 @@ def main(argv): > description='Generate color space conversion table coefficients with ' > 'configurable fixed-point precision.' > ) > + parser.add_argument('--invert', '-i', action='store_true', > + help='Invert the color space conversion (YUV -> RGB)') > parser.add_argument('--precision', '-p', default='Q1.7', > help='The output fixed point precision in Q notation (sign bit excluded)') > parser.add_argument('--quantization', '-q', choices=['full', 'limited'], > @@ -171,13 +170,25 @@ def main(argv): > luma = True > scaled_coeffs = [] > for line in encoding: > - line = [scale_coeff(coeff, quantization, luma, precision.fractional) for coeff in line] > + line = [scale_coeff(coeff, quantization, luma) for coeff in line] > scaled_coeffs.append(line) > luma = False > > + if args.invert: > + scaled_coeffs = np.linalg.inv(scaled_coeffs) > + > rounded_coeffs = [] > for line in scaled_coeffs: > - line = round_array(line) > + line = [coeff * (1 << precision.fractional) for coeff in line] > + # For the RGB to YUV conversion, use a rounding method that preserves > + # the rounded sum of each line to avoid biases and overflow, as the sum > + # of luma and chroma coefficients should be 1.0 and 0.0 respectively > + # (in full range). The the YUV to RGB conversion, there is no such The the Presumably that should be 'In the', or 'For the'. Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > + # constraint, so use simple rounding. > + if args.invert: > + line = [round(coeff) for coeff in line] > + else: > + line = round_array(line) > > # Convert coefficients to the number of bits selected by the precision. > # Negative values will be turned into positive integers using 2's > @@ -188,7 +199,7 @@ def main(argv): > # Print the result as C code. > nbits = 1 << (precision.total - 1).bit_length() > nbytes = nbits // 4 > - print(f'static const u{nbits} rgb2yuv_{args.encoding}_{quantization.name.lower()}_coeffs[] = {{') > + print(f'static const u{nbits} {"yuv2rgb" if args.invert else "rgb2yuv"}_{args.encoding}_{quantization.name.lower()}_coeffs[] = {{') > > for line in rounded_coeffs: > line = [f'0x{coeff:0{nbytes}x}' for coeff in line] > > base-commit: ed591e705c451d0ce14988ae96829a31a2ae2f9a > -- > Regards, > > Laurent Pinchart >
diff --git a/utils/rkisp1/gen-csc-table.py b/utils/rkisp1/gen-csc-table.py index 2fb702746421..f93e7cfacab6 100755 --- a/utils/rkisp1/gen-csc-table.py +++ b/utils/rkisp1/gen-csc-table.py @@ -7,6 +7,7 @@ import argparse import enum +import numpy as np import sys @@ -63,9 +64,8 @@ class Quantization(enum.Enum): LIMITED = 1 -def scale_coeff(coeff, quantization, luma, precision): - """Scale a coefficient to the output range dictated by the quantization and - the precision. +def scale_coeff(coeff, quantization, luma): + """Scale a coefficient to the output range dictated by the quantization. Parameters ---------- @@ -75,9 +75,6 @@ def scale_coeff(coeff, quantization, luma, precision): The quantization, either FULL or LIMITED luma : bool True if the coefficient corresponds to a luma value, False otherwise - precision : int - The desired precision for the scaled coefficient as a number of - fractional bits """ # Assume the input range is 8 bits. The output range is set by the @@ -91,7 +88,7 @@ def scale_coeff(coeff, quantization, luma, precision): else: out_range = 240 - 16 - return coeff * out_range / in_range * (1 << precision) + return coeff * out_range / in_range def round_array(values): @@ -150,6 +147,8 @@ def main(argv): description='Generate color space conversion table coefficients with ' 'configurable fixed-point precision.' ) + parser.add_argument('--invert', '-i', action='store_true', + help='Invert the color space conversion (YUV -> RGB)') parser.add_argument('--precision', '-p', default='Q1.7', help='The output fixed point precision in Q notation (sign bit excluded)') parser.add_argument('--quantization', '-q', choices=['full', 'limited'], @@ -171,13 +170,25 @@ def main(argv): luma = True scaled_coeffs = [] for line in encoding: - line = [scale_coeff(coeff, quantization, luma, precision.fractional) for coeff in line] + line = [scale_coeff(coeff, quantization, luma) for coeff in line] scaled_coeffs.append(line) luma = False + if args.invert: + scaled_coeffs = np.linalg.inv(scaled_coeffs) + rounded_coeffs = [] for line in scaled_coeffs: - line = round_array(line) + line = [coeff * (1 << precision.fractional) for coeff in line] + # For the RGB to YUV conversion, use a rounding method that preserves + # the rounded sum of each line to avoid biases and overflow, as the sum + # of luma and chroma coefficients should be 1.0 and 0.0 respectively + # (in full range). The the YUV to RGB conversion, there is no such + # constraint, so use simple rounding. + if args.invert: + line = [round(coeff) for coeff in line] + else: + line = round_array(line) # Convert coefficients to the number of bits selected by the precision. # Negative values will be turned into positive integers using 2's @@ -188,7 +199,7 @@ def main(argv): # Print the result as C code. nbits = 1 << (precision.total - 1).bit_length() nbytes = nbits // 4 - print(f'static const u{nbits} rgb2yuv_{args.encoding}_{quantization.name.lower()}_coeffs[] = {{') + print(f'static const u{nbits} {"yuv2rgb" if args.invert else "rgb2yuv"}_{args.encoding}_{quantization.name.lower()}_coeffs[] = {{') for line in rounded_coeffs: line = [f'0x{coeff:0{nbytes}x}' for coeff in line]