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{ "id": 25583, "url": "https://patchwork.libcamera.org/api/1.1/patches/25583/?format=api", "web_url": "https://patchwork.libcamera.org/patch/25583/", "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": "<20251217100138.82525-11-bryan.odonoghue@linaro.org>", "date": "2025-12-17T10:01:22", "name": "[v9,10/26] libcamera: shaders: Add support for contrast", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "d6ede263ceeb9481d7f326b36781ecb2b49b871d", "submitter": { "id": 175, "url":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/25583/mbox/", "series": [ { "id": 5669, "url": "https://patchwork.libcamera.org/api/1.1/series/5669/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5669", "date": "2025-12-17T10:01:12", "name": "Add GLES 2.0 GPUISP to libcamera", "version": 9, "mbox": "https://patchwork.libcamera.org/series/5669/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/25583/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/25583/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 0F404C3257\n\tfor <parsemail@patchwork.libcamera.org>;\n\tWed, 17 Dec 2025 10:02:08 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 7D75D61EF2;\n\tWed, 17 Dec 2025 11:02:07 +0100 (CET)", "from mail-wm1-x329.google.com (mail-wm1-x329.google.com\n\t[IPv6:2a00:1450:4864:20::329])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DA77961A62\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tWed, 17 Dec 2025 11:01:54 +0100 (CET)", "by mail-wm1-x329.google.com with SMTP id\n\t5b1f17b1804b1-4779cc419b2so55738595e9.3\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tWed, 17 Dec 2025 02:01:54 -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\t5b1f17b1804b1-47bdc1583fbsm32292585e9.0.2025.12.17.02.01.52\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tWed, 17 Dec 2025 02:01:53 -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=\"n4Svz3os\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=linaro.org; s=google; t=1765965714; x=1766570514;\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=dN8UZt6qlRDwenuDplOdpGWNKDU85eQ9zmywwDQb0Cg=;\n\tb=n4Svz3os/ZSF1ubDiTvqlnqNBDZeBk5MV/Vhmg0oh7nWIuExvYLC4uwNGJedbbnih6\n\tnQ9HitrmFKHoHtv/A60DTYDZQY4XToefZ0H2qcXDs+F3nEqNhcGndKUxvxU7PQEJOi03\n\tWaBIiOIr+KTTEyW4ETEQ6nKIvgakGbTrok45LnhAHDqIguw/A92ZkiKy6lFpkLwPomMW\n\tG3bTUPvBaA4Z4gE1joZmZ8URQmlQQSdh2z61tb6ZpSBHAGDYePMigJ+7WaSQlAHblISu\n\tuMTW2QyyVTqFPh3j6BDrOAnrCkTm1k0ohsnjFHKOSE2pIqCYA8RkGAhxIh0y87Yhx7aI\n\tBr9Q==", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1765965714; x=1766570514;\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=dN8UZt6qlRDwenuDplOdpGWNKDU85eQ9zmywwDQb0Cg=;\n\tb=eGXW5vDpNILcPYsZZptIJ8HxLwwg7L6ty2rQPe5NPNYK3zuOTP72NPXD2B2SqYsz8k\n\tJ2wcmT362Wix14kClf8R99sO6FrDcuzCbnQwH7rqgVA2gQkdPhd0uIIPWL0TSWJi5lA5\n\tveTwqOp9N7LuNRaviDh9p3gI9niYmY83YX1fWHVdujoBkpXzZojfh4p+2tblfKx7bAD4\n\ttbLvm+Qs5fY5j/NM6qkTLu9l5QfUSFzBkeY0VA2SSfQ6v9I/MdslUPMxr4JyoLS2cddJ\n\tRMxRH5/t793ob+jh27GAocdSuYaYOjpD8zfZV+j08QpX5ERD12gqoSsGCo/gCzDyweRP\n\tbMdw==", "X-Gm-Message-State": "AOJu0YzpJ+DlPIPrvtrLFDpEOmPItOQ6+q+nRFHklw0CAuCOIhndF5Kd\n\tJu+mQhRGfAJ+EdpK0B8surHXFu5W3xEd32slO/6hy/7K1AwZc5ExSGhmJnGHGi3Yx17XmVszXGu\n\t5P79W", "X-Gm-Gg": "AY/fxX57E85XbO0YQpLlLS3MpIfl/GjIRseiyYRM0A2XF6Qr8+i5ZaJps06qG81hgMJ\n\tShDbU9N6jWbrYM48yOFTAJZosdQou/ct5UbBSp/tUSuhCxiZhV2JuaMui0y2ZBM2DYQvNNu6jCj\n\tpQ+hXdj3ZghmW/tOS1kSE/DexuPLvh5NXf3FnBGIubLLTLXwAMb6dVEN2UijgBm9kbPncA+KelA\n\tGq6j8NdGlhBioCjcGqFDJn20N2DVcxzQ+U9QPtvZ1S1vSpxcof6u5cDUjI2asCAdObylUZPviXw\n\tum50imzco0imFseXmn/uBp43JnelnKWq7PUdm2Z2d449yezh4SyMzlx3/u0YJyRB0UAq1S9uH0g\n\tECt5TOKcxej4SszLlc30GZ3goCZVSZzQeJYEdQe/XBBDF1NmvwaJLlJ407+BibezQA6fL6UD+Hr\n\tIoSxKI6mh0WMF4ip23w3f+xHq5T59tT0f5R2IpvYXoWVQAruSPuvhN+PH9FsoHU0D2qq9v0oQZ0\n\tER2rQ==", "X-Google-Smtp-Source": "AGHT+IHT248ilUmvEhxuKRiaCo+h+yFbzkDYPSfpUx0aBzdzbV56JKyZ1hxs7fKMdo0wq1jQ0E7oHQ==", "X-Received": "by 2002:a05:600c:1994:b0:477:a978:3a7b with SMTP id\n\t5b1f17b1804b1-47a8f905675mr155006335e9.22.1765965714017; \n\tWed, 17 Dec 2025 02:01:54 -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 v9 10/26] libcamera: shaders: Add support for contrast", "Date": "Wed, 17 Dec 2025 10:01:22 +0000", "Message-ID": "<20251217100138.82525-11-bryan.odonoghue@linaro.org>", "X-Mailer": "git-send-email 2.52.0", "In-Reply-To": "<20251217100138.82525-1-bryan.odonoghue@linaro.org>", "References": "<20251217100138.82525-1-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 | 21 +++++++++++++++++++++\n src/libcamera/shaders/bayer_unpacked.frag | 21 +++++++++++++++++++++\n 2 files changed, 42 insertions(+)", "diff": "diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag\nindex 77d9fbfa7..0b730070e 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 contrast;\n+\n+float apply_contrast(float value, float contrastExp)\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 +271,17 @@ 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+\tfloat contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001));\n+\n+\trgb = clamp(rgb, 0.0, 1.0);\n+\trgb.r = apply_contrast(rgb.r, contrastExp);\n+\trgb.g = apply_contrast(rgb.g, contrastExp);\n+\trgb.b = apply_contrast(rgb.b, contrastExp);\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..114e32058 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 contrast;\n+\n+float apply_contrast(float value, float contrastExp)\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 +166,17 @@ 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+ * Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2)\n+ */\n+ float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001));\n+\n+ rgb = clamp(rgb, 0.0, 1.0);\n+ rgb.r = apply_contrast(rgb.r, contrastExp);\n+ rgb.g = apply_contrast(rgb.g, contrastExp);\n+ rgb.b = apply_contrast(rgb.b, contrastExp);\n+\n /* Apply gamma after colour correction */\n rgb = pow(rgb, vec3(gamma));\n \n", "prefixes": [ "v9", "10/26" ] }