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{ "id": 25427, "url": "https://patchwork.libcamera.org/api/1.1/patches/25427/?format=api", "web_url": "https://patchwork.libcamera.org/patch/25427/", "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": "<20251210005354.44726-11-bryan.odonoghue@linaro.org>", "date": "2025-12-10T00:53:38", "name": "[v7,10/26] libcamera: shaders: Add support for contrast", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "80a9b183b0bdc2e3d46d30c962434460e01cd193", "submitter": { "id": 175, "url":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/25427/mbox/", "series": [ { "id": 5645, "url": "https://patchwork.libcamera.org/api/1.1/series/5645/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5645", "date": "2025-12-10T00:53:28", "name": "Add GLES 2.0 GPUISP to libcamera", "version": 7, "mbox": "https://patchwork.libcamera.org/series/5645/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/25427/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/25427/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 DD732C3257\n\tfor <parsemail@patchwork.libcamera.org>;\n\tWed, 10 Dec 2025 00:54:44 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9DA986146C;\n\tWed, 10 Dec 2025 01:54:44 +0100 (CET)", "from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com\n\t[IPv6:2607:f8b0:4864:20::42e])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id A33756144E\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tWed, 10 Dec 2025 01:54:43 +0100 (CET)", "by mail-pf1-x42e.google.com with SMTP id\n\td2e1a72fcca58-7aa2170adf9so5242854b3a.0\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue, 09 Dec 2025 16:54:43 -0800 (PST)", "from inspiron14p-linux (p96936b06.osaknt01.ap.so-net.ne.jp.\n\t[150.147.107.6]) by smtp.gmail.com with ESMTPSA id\n\t41be03b00d2f7-bf6875cc8eesm16057762a12.16.2025.12.09.16.54.40\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tTue, 09 Dec 2025 16:54:41 -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=\"S+/bpJv0\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=linaro.org; s=google; t=1765328082; x=1765932882;\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=6jMRVHzcG6H3MVoD6kRHlh/HsNgMJfbon1fvfVhm+Ns=;\n\tb=S+/bpJv0OEzTE5t3znoJuAg5MgDY2uR6LTsg9lRsVS/vJRHGPM9vH3iZhB7x5MNPLo\n\tqUR8GDVDpa8G41Fh/cftK7FxqGiE/Pseuq50W4zAGdipULnlpZTc2QGGTUvrEs5Q9OP1\n\tKwCxzn/7U5O+pFiaD8HtCYlnGNv3cTfWX1SS1NpkQUdEi/bp4pkOQnsVIRoMOhApDLMU\n\tQLDXmpaf/uRRWLlkWIuIBHbBquQCMGAHdFsCkNJ6jKAihW5VetweFeYdTeP9makR+IvV\n\tCOlMZyk218jF5ISyeIhULgnlqfX4xgImvgGYalqX2v8ph7txwIzdJ5SA9U9PBvwu0LhA\n\t3GRQ==", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1765328082; x=1765932882;\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=6jMRVHzcG6H3MVoD6kRHlh/HsNgMJfbon1fvfVhm+Ns=;\n\tb=dB1Xo1NTK29Za9HPRs7kLeRwEGQ6s6qRj66AiCqn2whzA02Sg6++WYHLde4Q6UXMhc\n\tUmFtprkcKxoCdLAgG61ez+d6LHaUoXCLcfZG5O2u/OdjjSVhUM5H3e08mQ/F729dvhp/\n\t9oKw9p81p032cF6AS2+4MZp2MGzp9RNKYAh2DF47f8RRBQNbQdwk3GTqHatTlLUG+uAR\n\tbUqPhErFo8/D8x8TlnVTP/c94NDL5TWjzIMzGJnfxTaOHnmKYbT00ZgCpl3bVBTneN+m\n\t6qif2Wq1Dg+GHE60tj+Vb6IBjQw8CJyt6mwGmZ2rNl3KEw7bDE5jjYtlPM7naA7OZJI9\n\tamcA==", "X-Gm-Message-State": "AOJu0Yy9tZrZhEGMgKbirzSCJpo0BuacL1dpbeWTJQr0g9OU1alvczVc\n\tg/cSZFF3JvTDNJMBQNck+iwam2h2S6Upejqd5o4/VhuhfIYXoEClUck8np8sLsCuE6Bd6hCMCxj\n\tkOBkx", "X-Gm-Gg": "ASbGncvjsRcJmeGwty/yrrJI3HKOrLYaStOqHotF3Lq5Zf4MUMeT3XPJqz7aB3SBCgW\n\teuAkRpy1QTgN/jQVjej9jZeiAwDmh7zcGrjeRP66d8fs/RczReXbw88cEEMC+QACFoz7gidxXru\n\t0ozFuCO0w82QCtcQEG4pBnuSw7XwvamOKEPZeklQRZYOvM820Ia0bV8o96D1n+1aVjL5PrGPdbV\n\t4hSirxUbtSwiKdXEBRKMsw2+qh4ltPYkZsNAtwx9cvM92bx2gqiI1azfBt2G1Rlv3Lpy9UjETxp\n\tzvMDPhX0E/WiQoAyY/0v6FPAejkNXfDFCJsZHi3eAy2bY6B+sEz6CERMcKoiyW4XMwU7ngrwz3B\n\tDQMaYwyjLnFy/R5xdF0UZ3O7TZ8uBaZv0ST7aQTvNiOXlZCxYOev6nDFe8/aNvBsvAnYIZzSOVs\n\t4x9CBqIyPxuRQ7Y2TmBUIjCRFmtQC5voXwo3VkrZubvGvkzJKP8ulhsW3QNnz5o1+j", "X-Google-Smtp-Source": "AGHT+IEeSPSpK/rguyjCKRW2kAwlC7govDR4w678Ro82xhEEDy8BEmlUGZZG6CBFtMNs7l8C54n2uQ==", "X-Received": "by 2002:a05:6a20:5483:b0:35f:6e12:186f with SMTP id\n\tadf61e73a8af0-366e07dacbamr530449637.23.1765328081907; \n\tTue, 09 Dec 2025 16:54:41 -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 v7 10/26] libcamera: shaders: Add support for contrast", "Date": "Wed, 10 Dec 2025 00:53:38 +0000", "Message-ID": "<20251210005354.44726-11-bryan.odonoghue@linaro.org>", "X-Mailer": "git-send-email 2.52.0", "In-Reply-To": "<20251210005354.44726-1-bryan.odonoghue@linaro.org>", "References": "<20251210005354.44726-1-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>\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 | 19 +++++++++++++++++++\n 2 files changed, 38 insertions(+)", "diff": "diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag\nindex 77d9fbfa7..eea237dfc 100644\n--- a/src/libcamera/shaders/bayer_1x_packed.frag\n+++ b/src/libcamera/shaders/bayer_1x_packed.frag\n@@ -68,6 +68,19 @@ uniform sampler2D tex_y;\n uniform mat3 ccm;\n uniform vec3 blacklevel;\n uniform float gamma;\n+uniform float contrast;\n+\n+float apply_contrast(float value)\n+{\n+\t// Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2)\n+\tfloat contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001));\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 +274,12 @@ 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// Contrast\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..1226fe075 100644\n--- a/src/libcamera/shaders/bayer_unpacked.frag\n+++ b/src/libcamera/shaders/bayer_unpacked.frag\n@@ -27,6 +27,19 @@ varying vec4 xCoord;\n uniform mat3 ccm;\n uniform vec3 blacklevel;\n uniform float gamma;\n+uniform float contrast;\n+\n+float apply_contrast(float value)\n+{\n+ // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2)\n+ float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001));\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 +169,12 @@ 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+ // Contrast\n+ rgb = clamp(rgb, 0.0, 1.0);\n+ rgb.r = apply_contrast(rgb.r, contrast);\n+ rgb.g = apply_contrast(rgb.g, contrast);\n+ rgb.b = apply_contrast(rgb.b, contrast);\n+\n /* Apply gamma after colour correction */\n rgb = pow(rgb, vec3(gamma));\n \n", "prefixes": [ "v7", "10/26" ] }