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{ "id": 25525, "url": "https://patchwork.libcamera.org/api/1.1/patches/25525/?format=api", "web_url": "https://patchwork.libcamera.org/patch/25525/", "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": "<20251212002937.3118-11-bryan.odonoghue@linaro.org>", "date": "2025-12-12T00:29:21", "name": "[v8,10/26] libcamera: shaders: Add support for contrast", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "d6ede263ceeb9481d7f326b36781ecb2b49b871d", "submitter": { "id": 175, "url":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/25525/mbox/", "series": [ { "id": 5657, "url": "https://patchwork.libcamera.org/api/1.1/series/5657/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5657", "date": "2025-12-12T00:29:11", "name": "Add GLES 2.0 GPUISP to libcamera", "version": 8, "mbox": "https://patchwork.libcamera.org/series/5657/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/25525/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/25525/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 8A8F7BD1F1\n\tfor <parsemail@patchwork.libcamera.org>;\n\tFri, 12 Dec 2025 00:33:58 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 42A906168E;\n\tFri, 12 Dec 2025 01:33:58 +0100 (CET)", "from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com\n\t[IPv6:2607:f8b0:4864:20::42d])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E42F261635\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tFri, 12 Dec 2025 01:33:55 +0100 (CET)", "by mail-pf1-x42d.google.com with SMTP id\n\td2e1a72fcca58-7e1651ae0d5so592164b3a.1\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 11 Dec 2025 16:33:55 -0800 (PST)", "from inspiron14p-linux (p99250-ipoefx.ipoe.ocn.ne.jp.\n\t[153.246.134.249]) by smtp.gmail.com with ESMTPSA id\n\t41be03b00d2f7-c0c26eb0f6bsm3317282a12.14.2025.12.11.16.33.51\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tThu, 11 Dec 2025 16:33:53 -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=\"hKteUxNY\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=linaro.org; s=google; t=1765499634; x=1766104434;\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=hKteUxNYqaFPD0AXzSSJCPoSWv5u4LGGq8fiYjz12DBEHslvpsV4yZGGO8acUR1g2/\n\tgHHTf0iM2sYKvrsR9aEFaGtfq1aIqTmhryT6fej6HiFBoGOqZpKrOCDYqT3c3r89j+H7\n\tDRiVRdO5OzlvblsDl/TNSX4vlw0gMcO7/VRvoFcohrignYH/83DDxIKE3KZOGe8cn6yp\n\tU3qMydgW/p1ZfAkmRMA8n/X3Sw0MeUDs2/dV7ZHIO86hoe1CkCVRbETEQ3p/fkWjnszJ\n\tWztF9twKrUFITUifJ+/7A1VAT8lV9jaUdps3xTqBfpEwAaFduU6Bwxu5KaktR0C2OM0p\n\tmchQ==", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1765499634; x=1766104434;\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=LZMgoVhGm5kVFseH1s8aBbHTM6PDaoddZLbkLB7HGPMUHAvQqquVgitrbrKxRAegE3\n\tuvItCnePl3Y7Y8Thkx2nXFc01lAQ5Wf7S0dzW7hCWsEv1z/aym9X4eeyuQvLmr3h89U9\n\t+O0Pq/x7xid83zQCtFNHe59iLFxjAdP00kJA0GOk6Spk95gp3M1Yd28Rfg1vWQM0ssSA\n\tRIxqkSaba1g4+mY1fuAGcac62Evusnet5pGuzWEcjO8z21lImBEgmHx08tlPlXuw6SlA\n\tDC+kkqqLKPGV5mmSnjhMP+hN9mgZeaLRJeXuHdb1ryX6xyIJlE/j3DwW6f42gHGJ77cN\n\tqNaA==", "X-Gm-Message-State": "AOJu0YxmNR3LzhPhVMq3fdP5RpJrpzOK3FsVkGM/W8rzZPE++5HwQcSP\n\t9N80VR0UHMgKp+QXZjWUkVgutFFOZ0ZCpRwjVEuX9t9GOt0hnRqFnuVsYo8+UfI61V8s4upC02k\n\taf/Jm", "X-Gm-Gg": "AY/fxX6emuY6rFDiREVEX7sspcZvWp7tKweeHkUzHsC+LKWxAHawpZsjqSeYckMYnn2\n\tVkzULQpVzvq6OzM7+xO5nIexHSK+QZdipbfwEbbym9ePQSNn5q3UNz0EZrTG9qQtpYDtV/+tdLt\n\tPx3QoA7IsgP/6illN7cU26ShzE3b9f78iHqcmBJ82oVEpyx85h+L5HgL/SSPpe5X3s4f3ZsuRpT\n\t8lbPTuvsR4uGy8HuMGbGFovriywJtYI4gtIQU86wUXqGijflDm80KygmPxID6VmCZlXDW4mV68k\n\t0CELlaM0ORT2cpz9rOJgNoyx6A3HyGgPQpE9HWRW5HDzqFtCh1OR+MWm6Nr+VKDkvGv+7H/J+vO\n\tZjH1Iy31JoAK6Kqh0lrQQC3peGMhpO1uWIwd9xWLVDe8l5uG8hbFy4n9iCTDlAe/lNf2ACAJ7Of\n\ty1u6fZJGcsW4T5X/TQ/fm+6HgUg3QHqzcYGX0J0wej5ySB71s+IcaA32Kgo2HbB4s5CJlG8A==", "X-Google-Smtp-Source": "AGHT+IFrlauqKahU3yInGY0OzEsCeCYb7WzxgMij7edjwKkoRIGg540bRyLP6D5+zDeouPgYSH0ETA==", "X-Received": "by 2002:a05:6a20:6a21:b0:35f:27d:2ded with SMTP id\n\tadf61e73a8af0-369adfb33b3mr335863637.25.1765499634196; \n\tThu, 11 Dec 2025 16:33:54 -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 v8 10/26] libcamera: shaders: Add support for contrast", "Date": "Fri, 12 Dec 2025 00:29:21 +0000", "Message-ID": "<20251212002937.3118-11-bryan.odonoghue@linaro.org>", "X-Mailer": "git-send-email 2.52.0", "In-Reply-To": "<20251212002937.3118-1-bryan.odonoghue@linaro.org>", "References": "<20251212002937.3118-1-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": [ "v8", "10/26" ] }