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{ "id": 25664, "url": "https://patchwork.libcamera.org/api/1.1/patches/25664/?format=api", "web_url": "https://patchwork.libcamera.org/patch/25664/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20260106170059.56193-12-bryan.odonoghue@linaro.org>", "date": "2026-01-06T17:00:46", "name": "[v11,11/24] libcamera: shaders: Add support for contrast", "commit_ref": "e4effc1e3010211ea5f815f17ebac45b0dbdbd42", "pull_url": null, "state": "accepted", "archived": false, "hash": "f854a2739fe98e72907eff354a38e7735bf1ffc1", "submitter": { "id": 175, "url": "https://patchwork.libcamera.org/api/1.1/people/175/?format=api", "name": "Bryan O'Donoghue", "email": "bryan.odonoghue@linaro.org" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/25664/mbox/", "series": [ { "id": 5689, "url": "https://patchwork.libcamera.org/api/1.1/series/5689/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5689", "date": "2026-01-06T17:00:35", "name": "Add GLES 2.0 GPUISP to libcamera", "version": 10, "mbox": "https://patchwork.libcamera.org/series/5689/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/25664/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/25664/checks/", "tags": {}, "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "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 51842C3213\n\tfor <parsemail@patchwork.libcamera.org>;\n\tTue, 6 Jan 2026 17:01:21 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 19C606200C;\n\tTue, 6 Jan 2026 18:01:21 +0100 (CET)", "from mail-wr1-x434.google.com (mail-wr1-x434.google.com\n\t[IPv6:2a00:1450:4864:20::434])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id A77CC61FF4\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue, 6 Jan 2026 18:01:16 +0100 (CET)", "by mail-wr1-x434.google.com with SMTP id\n\tffacd0b85a97d-42fbc305552so816362f8f.0\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue, 06 Jan 2026 09:01:16 -0800 (PST)", "from inspiron14p-linux.ht.home (188-141-3-146.dynamic.upc.ie.\n\t[188.141.3.146]) by smtp.gmail.com with ESMTPSA id\n\tffacd0b85a97d-432bd0dadcfsm5515322f8f.3.2026.01.06.09.01.14\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tTue, 06 Jan 2026 09:01:15 -0800 (PST)" ], "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (2048-bit key;\n\tunprotected) header.d=linaro.org header.i=@linaro.org\n\theader.b=\"KiaeBcaV\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=linaro.org; s=google; t=1767718876; x=1768323676;\n\tdarn=lists.libcamera.org; \n\th=content-transfer-encoding:mime-version:references:in-reply-to\n\t:message-id:date:subject:cc:to:from:from:to:cc:subject:date\n\t:message-id:reply-to;\n\tbh=x/vTDR1Id8mqE5zdziJRdnnrmiapjAEMf9XvNPsLCKY=;\n\tb=KiaeBcaVsPxNDfZdZEg/rCPj6gmDYENJTWEH2o7D8Z5XnahcHemsa1L8Cq5Ppphzde\n\tYvfKycAdbVQUi7cZW7rXY3Vh6vfjKX6bEaZu6jfJTJPVtOFcrHGGkAnH+VUmY7EgqM9d\n\tivwkX02XSqFoW1j0VUTUmMF2SvCzQXS2BuvuqZZQsC/oCCPkLejGVXfzCGizpKs+GIJp\n\tYNkSCr6wr67EM6UwfR7plgRvpsrO9JJ9ce20rM3u9LP4DznDVaZZdejiFU3oJd6Atm9p\n\tVcJcSlaYjGSAkMXN55TTAQ80Uj+WdD8xWc0xU+SMC2O8qbck5UlZhHW/UPnuLadMgayd\n\tLTKg==", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1767718876; x=1768323676;\n\th=content-transfer-encoding:mime-version:references:in-reply-to\n\t:message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from\n\t:to:cc:subject:date:message-id:reply-to;\n\tbh=x/vTDR1Id8mqE5zdziJRdnnrmiapjAEMf9XvNPsLCKY=;\n\tb=kkS3/bA9Z1yQn5wvpw6Tcejz0/YD5FptvaXcGCD6y9z39t1+meiZr3dtWvgoaosW1R\n\tacUv1XH07aqI+esfnW5smHTcxcGKwgvjty52ohLVIfl+DUNT5KOqiTliobaNkrNv153t\n\tixQYCfcF+fSjOyOBOcn8EZOWn77hoT0zuN0+aM1hgE0VZbA30rBpcT/3BBc/eOshPaEq\n\tMVIfqtiPoXl/tJw/zxoZD8bfEzwOBaZMTsE8iE1XFj14hqFG+l7P+HiLlUtopwTNA+cF\n\tgYemRtZOZtwiN43jPBWH0h/0EfBKjXux6NaLDwduX4mheuwbejJryd/I/DUgmkkpv0fe\n\tis1A==", "X-Gm-Message-State": "AOJu0YysIIvyXp6/FeX3TPGSgYgrsbsiMaxmRqWwyvDLDZyA6JjW2DEQ\n\t6eCkhSgclsrKqmEPY3vn7AXYoPdr33uVCEGoHiJ7Q1KmLygIGa0w1xmnLv0jxQxZFGlBJNZiC8C\n\thCxl7yhI=", "X-Gm-Gg": "AY/fxX7FtN+EedTmS51w8bEsOfmPMLFzLmrqdLX0jY+ifj3tF9wuP1A546uDXwoH028\n\to1QM5h11gHHkDrhMqvPrwWqpxqXupJZ7P5PAmkrH6H/i3ekoTwJDsASoMPQ7pQ75igtqktQccWB\n\tQ1Ny3V4Pnh5lzmQC+RqRU5XUGS63eOLQ0/Rvw3NXqfrqgzSeKNfl9MoHtYH0T48NTrT3UkBjRSr\n\tLUNh6GT5RLRQM+IPlKuV0OhIKtlZ6GK8DoM12LJIh+rNF3IjgYgBKi7B+7fRd3HjKNgmp7jRjBr\n\tgnDNe0EEzyRMzKhsmwGs8HRiSRNIch5W4cJHyPXUcw8y0GxyZ70qeTGIcdv6G2wHDWLenji3W9Z\n\tXvwIbujUAfwFOyneeckhrPCVlX25A5Q3vvxYshQSp7EDUrJqGhgqm0RvV1kIyWXrFS+vYh726fD\n\tBjbL+HI2wWoUTAB2aOwg/5hOyxwo4ybSUzv1c8QbpNxSfnaEHgEUEzp6j5SgjnvN29QvE=", "X-Google-Smtp-Source": "AGHT+IH5psgNQ1Q2PXksIOut5FJSMKzpTAdyvJItUlBfbrks7UyevVqPrdO0Tz7CoGVTyLZhEl9ilQ==", "X-Received": "by 2002:a05:6000:2504:b0:430:f742:fbb2 with SMTP id\n\tffacd0b85a97d-432bc9d0bcdmr4626777f8f.19.1767718875854; \n\tTue, 06 Jan 2026 09:01:15 -0800 (PST)", "From": "Bryan O'Donoghue <bryan.odonoghue@linaro.org>", "To": "libcamera-devel@lists.libcamera.org", "Cc": "pavel@ucw.cz, Bryan O'Donoghue <bryan.odonoghue@linaro.org>,\n\tMilan Zamazal <mzamazal@redhat.com>", "Subject": "[PATCH v11 11/24] libcamera: shaders: Add support for contrast", "Date": "Tue, 6 Jan 2026 17:00:46 +0000", "Message-ID": "<20260106170059.56193-12-bryan.odonoghue@linaro.org>", "X-Mailer": "git-send-email 2.52.0", "In-Reply-To": "<20260106170059.56193-1-bryan.odonoghue@linaro.org>", "References": "<20260106170059.56193-1-bryan.odonoghue@linaro.org>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "Apply contrast after black-level and CCM operations.\n\nSuggested-by: Milan Zamazal <mzamazal@redhat.com>\nReviewed-by: Milan Zamazal <mzamazal@redhat.com>\nSigned-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>\n---\n src/libcamera/shaders/bayer_1x_packed.frag | 19 +++++++++++++++++++\n src/libcamera/shaders/bayer_unpacked.frag | 18 ++++++++++++++++++\n 2 files changed, 37 insertions(+)", "diff": "diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag\nindex 77d9fbfa7..23747f78a 100644\n--- a/src/libcamera/shaders/bayer_1x_packed.frag\n+++ b/src/libcamera/shaders/bayer_1x_packed.frag\n@@ -68,6 +68,16 @@ uniform sampler2D tex_y;\n uniform mat3 ccm;\n uniform vec3 blacklevel;\n uniform float gamma;\n+uniform float contrastExp;\n+\n+float apply_contrast(float value)\n+{\n+\t// Apply simple S-curve\n+\tif (value < 0.5)\n+\t\treturn 0.5 * pow(value / 0.5, contrastExp);\n+\telse\n+\t\treturn 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp);\n+}\n \n void main(void)\n {\n@@ -261,6 +271,15 @@ void main(void)\n \trgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]);\n \trgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]);\n \n+\t/*\n+\t * Contrast\n+\t * contrastExp 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2)\n+\t */\n+\trgb = clamp(rgb, 0.0, 1.0);\n+\trgb.r = apply_contrast(rgb.r);\n+\trgb.g = apply_contrast(rgb.g);\n+\trgb.b = apply_contrast(rgb.b);\n+\n \t/* Apply gamma after colour correction */\n \trgb = pow(rgb, vec3(gamma));\n \ndiff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag\nindex aba11a87f..af4a30c4b 100644\n--- a/src/libcamera/shaders/bayer_unpacked.frag\n+++ b/src/libcamera/shaders/bayer_unpacked.frag\n@@ -27,6 +27,16 @@ varying vec4 xCoord;\n uniform mat3 ccm;\n uniform vec3 blacklevel;\n uniform float gamma;\n+uniform float contrastExp;\n+\n+float apply_contrast(float value)\n+{\n+ // Apply simple S-curve\n+ if (value < 0.5)\n+ return 0.5 * pow(value / 0.5, contrastExp);\n+ else\n+ return 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp);\n+}\n \n void main(void) {\n vec3 rgb;\n@@ -156,6 +166,14 @@ void main(void) {\n rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]);\n rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]);\n \n+ /*\n+ * Contrast\n+ */\n+ rgb = clamp(rgb, 0.0, 1.0);\n+ rgb.r = apply_contrast(rgb.r);\n+ rgb.g = apply_contrast(rgb.g);\n+ rgb.b = apply_contrast(rgb.b);\n+\n /* Apply gamma after colour correction */\n rgb = pow(rgb, vec3(gamma));\n \n", "prefixes": [ "v11", "11/24" ] }