[{"id":32226,"web_url":"https://patchwork.libcamera.org/comment/32226/","msgid":"<87mshwhcom.fsf@redhat.com>","date":"2024-11-18T13:52:09","subject":"Re: [RFC PATCH v2 12/12] ipa: rkisp1: awb: Replace manual\n\tcalculations with Vector and Matrix","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Laurent Pinchart writes:\n\n> Processing of the statistics and estimation of the colour temperature\n> involve linear algebra. Replace the manual calculations with usage of\n> the Vector and Matrix classes.\n>\n> Signed-off-by: Laurent Pinchart \n\nReviewed-by: Milan Zamazal \n\n> ---\n> Changes since v1:\n>\n> - Adapt to Vector::normalize() being dropped\n> ---\n> src/ipa/rkisp1/algorithms/awb.cpp | 44 +++++++++++++++++++------------\n> 1 file changed, 27 insertions(+), 17 deletions(-)\n>\n> diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp\n> index 1c572055acdd..97163e0fa45c 100644\n> --- a/src/ipa/rkisp1/algorithms/awb.cpp\n> +++ b/src/ipa/rkisp1/algorithms/awb.cpp\n> @@ -169,17 +169,21 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,\n> \n> uint32_t Awb::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> }\n> \n> @@ -215,9 +219,11 @@ void Awb::process(IPAContext &context,\n> \t\trgbMeans.b() = awb->awb_mean[0].mean_cb_or_b;\n> \t} else {\n> \t\t/* Get the YCbCr mean values */\n> -\t\tdouble yMean = awb->awb_mean[0].mean_y_or_g;\n> -\t\tdouble cbMean = awb->awb_mean[0].mean_cb_or_b;\n> -\t\tdouble crMean = awb->awb_mean[0].mean_cr_or_r;\n> +\t\tVector yuvMeans({\n> +\t\t\tstatic_cast(awb->awb_mean[0].mean_y_or_g),\n> +\t\t\tstatic_cast(awb->awb_mean[0].mean_cb_or_b),\n> +\t\t\tstatic_cast(awb->awb_mean[0].mean_cr_or_r)\n> +\t\t});\n> \n> \t\t/*\n> \t\t * Convert from YCbCr to RGB.\n> @@ -231,12 +237,16 @@ void Awb::process(IPAContext &context,\n> \t\t * [1,1636, -0,4045, -0,7949]\n> \t\t * [1,1636, 1,9912, -0,0250]]\n> \t\t */\n> -\t\tyMean -= 16;\n> -\t\tcbMean -= 128;\n> -\t\tcrMean -= 128;\n> -\t\trgbMeans.r() = 1.1636 * yMean - 0.0623 * cbMean + 1.6008 * crMean;\n> -\t\trgbMeans.g() = 1.1636 * yMean - 0.4045 * cbMean - 0.7949 * crMean;\n> -\t\trgbMeans.b() = 1.1636 * yMean + 1.9912 * cbMean - 0.0250 * crMean;\n> +\t\tstatic const Matrix yuv2rgbMatrix({\n> +\t\t\t1.1636, -0.0623, 1.6008,\n> +\t\t\t1.1636, -0.4045, -0.7949,\n> +\t\t\t1.1636, 1.9912, -0.0250\n> +\t\t});\n> +\t\tstatic const Vector yuv2rgbOffset({\n> +\t\t\t16, 128, 128\n> +\t\t});\n> +\n> +\t\trgbMeans = yuv2rgbMatrix * (yuvMeans - yuv2rgbOffset);\n> \n> \t\t/*\n> \t\t * Due to hardware rounding errors in the YCbCr means, the","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 EAA3AC32DD\n\tfor ;\n\tMon, 18 Nov 2024 13:52:16 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9EA58658D8;\n\tMon, 18 Nov 2024 14:52:16 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 5DF0860532\n\tfor ;\n\tMon, 18 Nov 2024 14:52:15 +0100 (CET)","from mail-wm1-f70.google.com (mail-wm1-f70.google.com\n\t[209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-611-kpqzGtdhOFifSNetK1xTAA-1; 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\n\tMon, 18 Nov 2024 05:52:11 -0800 (PST)","by 2002:a05:600c:3b96:b0:431:53db:3d29 with SMTP id\n\t5b1f17b1804b1-432df74d944mr98771195e9.18.1731937931344; \n\tMon, 18 Nov 2024 05:52:11 -0800 (PST)"],"X-Google-Smtp-Source":"AGHT+IH+4VDnZ98PSlGccIXlDO2m7xQ+/klSr1Pigu7PycmMveMddpIL4rUbwbXCj1boJLgER1+Axw==","From":"Milan Zamazal ","To":"Laurent Pinchart ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [RFC PATCH v2 12/12] ipa: rkisp1: awb: Replace manual\n\tcalculations with Vector and Matrix","In-Reply-To":"<20241118000738.18977-13-laurent.pinchart@ideasonboard.com>\n\t(Laurent Pinchart's message of \"Mon, 18 Nov 2024 02:07:38 +0200\")","References":"<20241118000738.18977-1-laurent.pinchart@ideasonboard.com>\n\t<20241118000738.18977-13-laurent.pinchart@ideasonboard.com>","Date":"Mon, 18 Nov 2024 14:52:09 +0100","Message-ID":"<87mshwhcom.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":"pumcxo3g19b0fZ07n0vGB2TYsDai3Tm5SvhEKDHQ8ZY_1731937932","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\" "}}]