[{"id":39705,"web_url":"https://patchwork.libcamera.org/comment/39705/","msgid":"","date":"2026-07-15T00:26:27","subject":"Re: [RFC PATCH v7 2/6] libcamera: software_isp: Add LSC data to\n\tDebayerParams","submitter":{"id":226,"url":"https://patchwork.libcamera.org/api/people/226/","name":"Bryan O'Donoghue","email":"bod.linux@nxsw.ie"},"content":"On 08/07/2026 21:18, Milan Zamazal wrote:\n> From: Xander Pronk \n> \n> Add a lookup table for grid-based lens shading correction to debayer\n> params. The lookup table is in the format of an RGB texture to be\n> passed to debayering.\n> \n> The parameter is filled in by Lsc algorithm implemented in a followup\n\nLSC\n\nfollow-up\n\n> patch. If the algorithm is not enabled, the parameter content is\n> arbitrary and the parameter may not be used. The parameter is currently\n> unused, its handling is implemented in a followup patch.\n> \n> There is no special meaning about the selected grid size, it's\n> just one of the smaller common sizes.\n> \n> Co-developed-by: Rick ten Wolde \n> Signed-off-by: Rick ten Wolde \n> Signed-off-by: Xander Pronk \n> Signed-off-by: Milan Zamazal \n> ---\n> .../internal/software_isp/debayer_params.h | 9 +++++\n> src/libcamera/software_isp/debayer.cpp | 33 +++++++++++++++++++\n> 2 files changed, 42 insertions(+)\n> \n> diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h\n> index 1074720d7..4eb6c7e8d 100644\n> --- a/include/libcamera/internal/software_isp/debayer_params.h\n> +++ b/include/libcamera/internal/software_isp/debayer_params.h\n> @@ -10,6 +10,7 @@\n> \n> #pragma once\n> \n> +#include \n> #include \n> \n> #include \"libcamera/internal/matrix.h\"\n> @@ -25,6 +26,14 @@ struct DebayerParams {\n> \tfloat gamma = 1.0;\n> \tfloat contrastExp = 1.0;\n> \tRGB gains = RGB({ 1.0, 1.0, 1.0 });\n> +\n> +\tstatic constexpr unsigned int kLscGridSize = 16;\n> +\tstatic constexpr unsigned int kLscValuesPerCell = 3;\n> +\tusing LscValueType = float;\n> +\tusing LscLookupTable =\n> +\t\tstd::array;\n\nIs there really a use-case for having LscvalueType at all - we will \npretty much be float forever right ?\n\nOtherwise seems reasonable to me.","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 D7A13C32CE\n\tfor ;\n\tWed, 15 Jul 2026 00:26:35 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 4E87C66155;\n\tWed, 15 Jul 2026 02:26:34 +0200 (CEST)","from tor.source.kernel.org (tor.source.kernel.org\n\t[IPv6:2600:3c04:e001:324:0:1991:8:25])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 23CE766152\n\tfor ;\n\tWed, 15 Jul 2026 02:26:33 +0200 (CEST)","from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18])\n\tby tor.source.kernel.org (Postfix) with ESMTP id 9B058600BB;\n\tWed, 15 Jul 2026 00:26:31 +0000 (UTC)","by smtp.kernel.org (Postfix) with ESMTPSA id DA9BE1F000E9;\n\tWed, 15 Jul 2026 00:26:29 +0000 (UTC)"],"Message-ID":"","Date":"Wed, 15 Jul 2026 01:26:27 +0100","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [RFC PATCH v7 2/6] libcamera: software_isp: Add LSC data to\n\tDebayerParams","To":"Milan Zamazal , libcamera-devel@lists.libcamera.org","Cc":"Xander Pronk ,\n\tHans de Goede ,\n\tLaurent Pinchart ,\n\tRick ten Wolde ","References":"<20260708201816.299983-1-mzamazal@redhat.com>\n\t\n\t<20260708201816.299983-3-mzamazal@redhat.com>","From":"Bryan O'Donoghue ","Content-Language":"en-GB","In-Reply-To":"<20260708201816.299983-3-mzamazal@redhat.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"7bit","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\" "}},{"id":39710,"web_url":"https://patchwork.libcamera.org/comment/39710/","msgid":"<85zezsn0r3.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-07-15T07:57:36","subject":"Re: [RFC PATCH v7 2/6] libcamera: software_isp: Add LSC data to\n\tDebayerParams","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Bryan O'Donoghue writes:\n\n> On 08/07/2026 21:18, Milan Zamazal wrote:\n>> From: Xander Pronk \n>> Add a lookup table for grid-based lens shading correction to debayer\n>\n>> params. The lookup table is in the format of an RGB texture to be\n>> passed to debayering.\n>> The parameter is filled in by Lsc algorithm implemented in a followup\n>\n> LSC\n\nLSC = Lens Shading Correction\nLsc = the name of the LSC algorithm in `simple' pipeline\n\n> follow-up\n\nack\n\n>> patch. If the algorithm is not enabled, the parameter content is\n>> arbitrary and the parameter may not be used. The parameter is currently\n>> unused, its handling is implemented in a followup patch.\n>> There is no special meaning about the selected grid size, it's\n>> just one of the smaller common sizes.\n>> Co-developed-by: Rick ten Wolde \n>> Signed-off-by: Rick ten Wolde \n>> Signed-off-by: Xander Pronk \n>> Signed-off-by: Milan Zamazal \n>> ---\n>> .../internal/software_isp/debayer_params.h | 9 +++++\n>> src/libcamera/software_isp/debayer.cpp | 33 +++++++++++++++++++\n>> 2 files changed, 42 insertions(+)\n>> diff --git a/include/libcamera/internal/software_isp/debayer_params.h\n>> b/include/libcamera/internal/software_isp/debayer_params.h\n>> index 1074720d7..4eb6c7e8d 100644\n>> --- a/include/libcamera/internal/software_isp/debayer_params.h\n>> +++ b/include/libcamera/internal/software_isp/debayer_params.h\n>> @@ -10,6 +10,7 @@\n>> #pragma once\n>> +#include \n>> #include \n>> #include \"libcamera/internal/matrix.h\"\n>> @@ -25,6 +26,14 @@ struct DebayerParams {\n>> \tfloat gamma = 1.0;\n>> \tfloat contrastExp = 1.0;\n>> \tRGB gains = RGB({ 1.0, 1.0, 1.0 });\n>> +\n>> +\tstatic constexpr unsigned int kLscGridSize = 16;\n>> +\tstatic constexpr unsigned int kLscValuesPerCell = 3;\n>> +\tusing LscValueType = float;\n>> +\tusing LscLookupTable =\n>> +\t\tstd::array;\n>\n> Is there really a use-case for having LscvalueType at all\n\nSince it is used only in two locations close to each other, it's not\nworth it, I'll remove it.\n\n> - we will pretty much be float forever right ?\n\nWould you like to take a bet? :-)\n\n> Otherwise seems reasonable to me.","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 3092DC3304\n\tfor ;\n\tWed, 15 Jul 2026 07:57:45 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 6334066168;\n\tWed, 15 Jul 2026 09:57:44 +0200 (CEST)","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 9E2E866157\n\tfor ;\n\tWed, 15 Jul 2026 09:57:42 +0200 (CEST)","from mail-wm1-f69.google.com (mail-wm1-f69.google.com\n\t[209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-94-0fdA5nXIMh2A-u0oYwkhAg-1; Wed, 15 Jul 2026 03:57:40 -0400","by mail-wm1-f69.google.com with SMTP id\n\t5b1f17b1804b1-493bdaf8549so49024745e9.2\n\tfor ;\n\tWed, 15 Jul 2026 00:57:39 -0700 (PDT)","from mzamazal-thinkpadp1gen7.tpbc.csb\n\t(ip-77-48-47-4.net.vodafone.cz. 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