[{"id":32266,"web_url":"https://patchwork.libcamera.org/comment/32266/","msgid":"<874j43h5o1.fsf@redhat.com>","date":"2024-11-19T10:35:58","subject":"Re: [PATCH v3 14/17] ipa: libipa: colour: Use Vector and Matrix for\n\tlinear algebra","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Laurent Pinchart writes:\n\n> Replace the manual vector and matrix calculations with usage of the\n> Vector and Matrix classes. This simplifies the code and improves\n> readability.\n>\n> Signed-off-by: Laurent Pinchart \n\nReviewed-by: Milan Zamazal \n\n> ---\n> src/ipa/libipa/colours.cpp | 26 +++++++++++++++++---------\n> 1 file changed, 17 insertions(+), 9 deletions(-)\n>\n> diff --git a/src/ipa/libipa/colours.cpp b/src/ipa/libipa/colours.cpp\n> index 6c597093ddf8..97124cf460d4 100644\n> --- a/src/ipa/libipa/colours.cpp\n> +++ b/src/ipa/libipa/colours.cpp\n> @@ -31,7 +31,11 @@ namespace ipa {\n> */\n> double rec601LuminanceFromRGB(const RGB &rgb)\n> {\n> -\treturn (rgb.r() * .299) + (rgb.g() * .587) + (rgb.b() * .114);\n> +\tstatic const Vector rgb2y{{\n> +\t\t0.299, 0.587, 0.114\n> +\t}};\n> +\n> +\treturn rgb.dot(rgb2y);\n> }\n> \n> /**\n> @@ -54,17 +58,21 @@ double rec601LuminanceFromRGB(const RGB &rgb)\n> */\n> uint32_t estimateCCT(const RGB &rgb)\n> {\n> -\t/* Convert the RGB values to CIE tristimulus values (XYZ) */\n> -\tdouble X = (-0.14282) * rgb.r() + (1.54924) * rgb.g() + (-0.95641) * rgb.b();\n> -\tdouble Y = (-0.32466) * rgb.r() + (1.57837) * rgb.g() + (-0.73191) * rgb.b();\n> -\tdouble Z = (-0.68202) * rgb.r() + (0.77073) * rgb.g() + (0.56332) * rgb.b();\n> +\t/*\n> +\t * Convert the RGB values to CIE tristimulus values (XYZ) and divide by\n> +\t * the sum of X, Y and Z to calculate the CIE xy chromaticity.\n> +\t */\n> +\tstatic const Matrix rgb2xyz({\n> +\t\t-0.14282, 1.54924, -0.95641,\n> +\t\t-0.32466, 1.57837, -0.73191,\n> +\t\t-0.68202, 0.77073, 0.56332\n> +\t});\n> \n> -\t/* Calculate the normalized chromaticity values */\n> -\tdouble x = X / (X + Y + Z);\n> -\tdouble y = Y / (X + Y + Z);\n> +\tVector xyz = rgb2xyz * rgb;\n> +\txyz /= xyz.sum();\n> \n> \t/* Calculate CCT */\n> -\tdouble n = (x - 0.3320) / (0.1858 - y);\n> +\tdouble n = (xyz.x() - 0.3320) / (0.1858 - xyz.y());\n> \treturn 449 * n * n * n + 3525 * n * n + 6823.3 * n + 5520.33;\n> }","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 22D69C32F1\n\tfor ;\n\tTue, 19 Nov 2024 10:36:08 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 5BA9A65EF0;\n\tTue, 19 Nov 2024 11:36:07 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.133.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id A9C4A65EEB\n\tfor ;\n\tTue, 19 Nov 2024 11:36:05 +0100 (CET)","from mail-ej1-f69.google.com (mail-ej1-f69.google.com\n\t[209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-618-PkSENoy6NcSqEc35zTd8yw-1; 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\n\tTue, 19 Nov 2024 02:36:01 -0800 (PST)","by 2002:a17:907:2d90:b0:aa3:5ca5:2ca4 with SMTP id\n\ta640c23a62f3a-aa483441d9cmr1526575266b.25.1732012561081; \n\tTue, 19 Nov 2024 02:36:01 -0800 (PST)"],"X-Google-Smtp-Source":"AGHT+IF1/LImV7D8i6znnDwDJ7dy5YIBwdrUORHoxtLRLlwVHsA+Qn4sAe/70mfnK2ZvTEB0kaB9Fw==","From":"Milan Zamazal ","To":"Laurent Pinchart ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [PATCH v3 14/17] ipa: libipa: colour: Use Vector and Matrix for\n\tlinear algebra","In-Reply-To":"<20241118221618.13953-15-laurent.pinchart@ideasonboard.com>\n\t(Laurent Pinchart's message of \"Tue, 19 Nov 2024 00:16:15 +0200\")","References":"<20241118221618.13953-1-laurent.pinchart@ideasonboard.com>\n\t<20241118221618.13953-15-laurent.pinchart@ideasonboard.com>","Date":"Tue, 19 Nov 2024 11:35:58 +0100","Message-ID":"<874j43h5o1.fsf@redhat.com>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"TU5WNVDcSMlZPxvn-F71S7EpxUHxf7QgOLEjgVCvbbk_1732012562","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]