[{"id":37940,"web_url":"https://patchwork.libcamera.org/comment/37940/","msgid":"<0e2d6b19-853c-4b44-a833-0f76c6187bca@ideasonboard.com>","date":"2026-01-26T11:30:37","subject":"Re: [PATCH 4/7] libcamera: shaders: Add LSC support","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"content":"Hi\n\n2026. 01. 26. 11:42 keltezéssel, Rick ten Wolde írta:\n> From: Xander Pronk \n> \n> Apply LSC after black-level and before CCM operations.\n> \n> Co-authored-by: Rick ten Wolde \n> Signed-off-by: Rick ten Wolde \n> Signed-off-by: Xander Pronk \n> ---\n> src/libcamera/shaders/bayer_1x_packed.frag | 10 ++++++++++\n> src/libcamera/shaders/bayer_unpacked.frag | 10 ++++++++++\n> 2 files changed, 20 insertions(+)\n> \n> diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag\n> index 23747f78..7993ea1d 100644\n> --- a/src/libcamera/shaders/bayer_1x_packed.frag\n> +++ b/src/libcamera/shaders/bayer_1x_packed.frag\n> @@ -70,6 +70,10 @@ uniform vec3 blacklevel;\n> uniform float gamma;\n> uniform float contrastExp;\n> \n> +uniform sampler2D lsc_tex_red;\n> +uniform sampler2D lsc_tex_blue;\n> +uniform sampler2D lsc_tex_green;\n> +\n> float apply_contrast(float value)\n> {\n> \t// Apply simple S-curve\n> @@ -227,6 +231,12 @@ void main(void)\n> \n> \trgb = rgb - blacklevel;\n> \n> +\t#if defined(DO_LSC)\n> +\trgb.r = rgb.r + rgb.r * 3.0 * texture2D(lsc_tex_red, textureOut).x;\n> +\trgb.g = rgb.g + rgb.g * 3.0 * texture2D(lsc_tex_green, textureOut).x;\n> +\trgb.b = rgb.b + rgb.b * 3.0 * texture2D(lsc_tex_blue, textureOut).x;\n> +\t#endif\n\nAny reason for not using a single texture? Feels to me that would be\nmore efficient? Am I missing why three separate ones are needed?\n\n\nRegards,\nBarnabás Pőcze\n\n> +\n> \t/*\n> \t * CCM is a 3x3 in the format\n> \t *\n> diff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag\n> index 1b85196a..f0b9a6cc 100644\n> --- a/src/libcamera/shaders/bayer_unpacked.frag\n> +++ b/src/libcamera/shaders/bayer_unpacked.frag\n> @@ -29,6 +29,10 @@ uniform vec3 blacklevel;\n> uniform float gamma;\n> uniform float contrastExp;\n> \n> +uniform sampler2D lsc_tex_red;\n> +uniform sampler2D lsc_tex_blue;\n> +uniform sampler2D lsc_tex_green;\n> +\n> float apply_contrast(float value)\n> {\n> // Apply simple S-curve\n> @@ -130,6 +134,12 @@ void main(void) {\n> \n> rgb = rgb - blacklevel;\n> \n> + #if defined(DO_LSC)\n> + rgb.r = rgb.r + rgb.r * 3.0 * texture2D(lsc_tex_red, center.xy).x;\n> + rgb.g = rgb.g + rgb.g * 3.0 * texture2D(lsc_tex_green, center.xy).x;\n> + rgb.b = rgb.b + rgb.b * 3.0 * texture2D(lsc_tex_blue, center.xy).x;\n> + #endif\n> +\n> /*\n> * CCM is a 3x3 in the format\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 9502DC3220\n\tfor ;\n\tMon, 26 Jan 2026 11:30:40 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 53D2661FCC;\n\tMon, 26 Jan 2026 12:30:40 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 664E261A35\n\tfor ;\n\tMon, 26 Jan 2026 12:30:39 +0100 (CET)","from [192.168.33.36] (185.221.142.123.nat.pool.zt.hu\n\t[185.221.142.123])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 38FC422F;\n\tMon, 26 Jan 2026 12:30:02 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; 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charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","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":38079,"web_url":"https://patchwork.libcamera.org/comment/38079/","msgid":"","date":"2026-02-04T15:12:49","subject":"Re: [PATCH 4/7] libcamera: shaders: Add LSC support","submitter":{"id":226,"url":"https://patchwork.libcamera.org/api/people/226/","name":"Bryan O'Donoghue","email":"bod.linux@nxsw.ie"},"content":"On 26/01/2026 10:42, Rick ten Wolde wrote:\n> From: Xander Pronk \n> \n> Apply LSC after black-level and before CCM operations.\n> \n> Co-authored-by: Rick ten Wolde \n> Signed-off-by: Rick ten Wolde \n> Signed-off-by: Xander Pronk \n> ---\n> src/libcamera/shaders/bayer_1x_packed.frag | 10 ++++++++++\n> src/libcamera/shaders/bayer_unpacked.frag | 10 ++++++++++\n> 2 files changed, 20 insertions(+)\n> \n> diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag\n> index 23747f78..7993ea1d 100644\n> --- a/src/libcamera/shaders/bayer_1x_packed.frag\n> +++ b/src/libcamera/shaders/bayer_1x_packed.frag\n> @@ -70,6 +70,10 @@ uniform vec3 blacklevel;\n> uniform float gamma;\n> uniform float contrastExp;\n> \n> +uniform sampler2D lsc_tex_red;\n> +uniform sampler2D lsc_tex_blue;\n> +uniform sampler2D lsc_tex_green;\n> +\n> float apply_contrast(float value)\n> {\n> \t// Apply simple S-curve\n> @@ -227,6 +231,12 @@ void main(void)\n> \n> \trgb = rgb - blacklevel;\n> \n> +\t#if defined(DO_LSC)\n> +\trgb.r = rgb.r + rgb.r * 3.0 * texture2D(lsc_tex_red, textureOut).x;\n\nA little bit of description about the calculation here would be nice.\n\nAlso since you do the same thing three times, consider a method.\n\n> +\trgb.g = rgb.g + rgb.g * 3.0 * texture2D(lsc_tex_green, textureOut).x;\n> +\trgb.b = rgb.b + rgb.b * 3.0 * texture2D(lsc_tex_blue, textureOut).x;\n> +\t#endif\n> +\n> \t/*\n> \t * CCM is a 3x3 in the format\n> \t *\n> diff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag\n> index 1b85196a..f0b9a6cc 100644\n> --- a/src/libcamera/shaders/bayer_unpacked.frag\n> +++ b/src/libcamera/shaders/bayer_unpacked.frag\n> @@ -29,6 +29,10 @@ uniform vec3 blacklevel;\n> uniform float gamma;\n> uniform float contrastExp;\n> \n> +uniform sampler2D lsc_tex_red;\n> +uniform sampler2D lsc_tex_blue;\n> +uniform sampler2D lsc_tex_green;\n> +\n> float apply_contrast(float value)\n> {\n> // Apply simple S-curve\n> @@ -130,6 +134,12 @@ void main(void) {\n> \n> rgb = rgb - blacklevel;\n> \n> + #if defined(DO_LSC)\n> + rgb.r = rgb.r + rgb.r * 3.0 * texture2D(lsc_tex_red, center.xy).x;\n> + rgb.g = rgb.g + rgb.g * 3.0 * texture2D(lsc_tex_green, center.xy).x;\n> + rgb.b = rgb.b + rgb.b * 3.0 * texture2D(lsc_tex_blue, center.xy).x;\n> + #endif\n> +\n> /*\n> * CCM is a 3x3 in the format\n> *\n> --\n> 2.51.0\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 A7A8CC31E9\n\tfor ;\n\tWed, 4 Feb 2026 15:12:57 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0956262039;\n\tWed, 4 Feb 2026 16:12:57 +0100 (CET)","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 C1EFC61FBF\n\tfor ;\n\tWed, 4 Feb 2026 16:12:55 +0100 (CET)","from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58])\n\tby tor.source.kernel.org (Postfix) with ESMTP id 53161600C4;\n\tWed, 4 Feb 2026 15:12:54 +0000 (UTC)","by smtp.kernel.org (Postfix) with ESMTPSA id 58C9FC4CEF7;\n\tWed, 4 Feb 2026 15:12:52 +0000 (UTC)"],"Message-ID":"","Date":"Wed, 4 Feb 2026 15:12:49 +0000","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH 4/7] libcamera: shaders: Add LSC support","To":"Rick ten Wolde ,\n\tlibcamera-devel@lists.libcamera.org","Cc":"xander.c.pronk@gmail.com, derekgielen@outlook.com,\n\t22012540@student.hhs.nl, johannes.goede@oss.qualcomm.com,\n\tRick ten Wolde ","References":"<20260126104256.119697-1-rick.w.ten.wolde@gmail.com>\n\t\n\t<20260126104256.119697-5-rick.w.ten.wolde@gmail.com>","From":"Bryan O'Donoghue ","Content-Language":"en-US","In-Reply-To":"<20260126104256.119697-5-rick.w.ten.wolde@gmail.com>","Content-Type":"text/plain; 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