From patchwork Tue Dec 2 13:45:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bryan O'Donoghue X-Patchwork-Id: 25319 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id D7895C32EF for ; Tue, 2 Dec 2025 13:46:14 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 005C960D17; Tue, 2 Dec 2025 14:46:13 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b="cx1rFdu3"; dkim-atps=neutral Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 9795A60D1A for ; Tue, 2 Dec 2025 14:46:07 +0100 (CET) Received: by mail-wm1-x331.google.com with SMTP id 5b1f17b1804b1-4779d47be12so44926835e9.2 for ; Tue, 02 Dec 2025 05:46:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1764683166; x=1765287966; darn=lists.libcamera.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=C/sV5SonuYN3A35MLfu7GzsniU0bzqMrcJSwifQ1Hik=; b=cx1rFdu3zr+rQDeRvuCQRCpd9PQrDwhkYY12hpOPpI5FYd7gCoZDT2Hr5T1+m0Ik/p A/lRp2bKNevHDjzXI0+SOholmNzck3YnjlYOXhHDLSzveKe9zlWq/ajp+oQtnGe5Bl7G rFsgRbEw5YoNdgY8GFIV/5rqSgq6b3bnGMB8nlAMMY8S6TYKnSwHQJFpouePascGW+XQ lZb4XdEu2mb1e5gtxv4oXdpD478PX315hLjrZrxoTIruBYOdlQe8RVM7cbNuUpO4ub9V mwlSkUUxVAzRoD4kLy9ENSndIRRB1hv5OzGgBjdOR88Uga6O7BwdgDHRuv8cmrzTrVKj PWMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764683166; x=1765287966; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=C/sV5SonuYN3A35MLfu7GzsniU0bzqMrcJSwifQ1Hik=; b=pSQzomaen7i8gDfaNxvLPBDnnuNSGgFfKelNuHECxhvbhH+fbj0CaYznCvLm+8pRP4 qRVDSu5hDFndUWMVbhhJy7kcw9gotjf/i6SEa1UXzxiKcq3+7I5Ue//OmUygcfF/BSNK 1/AB+2tHM248swqW1uexKhCJUgkEVGlKmClU3qzd0ReHHc0rjG/nWpzgGPWpYkFwVP0z kQ0IhvhSrGA6ZVijO5XesqB8f08KAK1Aj0GPWMt2gM9vNsyEFbt+bexvkTuPxtNz4/fu pBFWhfHMVNyuwhq/c+iL2WuujxlcBnjc4UY7wFDTiRfXF096QKgCFAsyuk48+rmXcGKk SsFQ== X-Gm-Message-State: AOJu0YxMcMGJMd21sbCOp0N+UvpCrC1z8XOc66gDOt83irdWushEFWZi WZco44GCuWmza+yiMbXvZBt8V3fGe7AB/S6UNbX3fKcUu3ucbeYne/MBbsbVF2WNfIK6zRSGVhQ uW4xa X-Gm-Gg: ASbGncvwm43dB0l+kTp7WdPynYWOvwNxeN9M/XeponXyN0p3KoMQQVWjoRg8/eoDVmz 2WLB3TH8KgT4lc6GJFb5dYBnrU/emTLBr073I+yxu5ETL9GqcsbmichZpEmakaYhlbsOmL6ZL5A T+EBtPBcsBe/fsICUANCFyLWmqtOlzw0TgHW2VyavjsdcKHLhYaC4dX8zQrhJqBLG9MHHplJ5XM TGQz0qi6vDMizeRy/81hd4nm9Ms7ert6IhlJfrOk5/nwKzkNBnYezm1BaleapF4uM5J95poJPGT wK2V3XzWGgu0nkC+6QTEeZg0zYNokOf7QJaEFsI93guJxxcw8Qu7t+C7+BxoY69BS/CG5cY3hHo aRmxNnVOIJ2cU5gFx8pO9tRNHrahOLfyj6JfaIivPZ/yDCUVZWqDTvTC39cvyiahxjQewR/5PjR bTDY8bB+zfCKqhK+Vef1SAaPydGk+tzv1OAIayIyLAdavGSApJnqdxArwLy7u8fwONLa0= X-Google-Smtp-Source: AGHT+IFofNvOacnLduLBPdUDH62M9if1OU5eoHP6UlGVwUjxgqWnAot+k6CNhiXEtjbAoaJJ0QrLFw== X-Received: by 2002:a05:600c:5494:b0:477:93f7:bbc5 with SMTP id 5b1f17b1804b1-477c0184c3amr404258905e9.10.1764683166581; Tue, 02 Dec 2025 05:46:06 -0800 (PST) Received: from inspiron14p-linux.ht.home (188-141-3-146.dynamic.upc.ie. [188.141.3.146]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47926f0ec69sm19383375e9.1.2025.12.02.05.46.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Dec 2025 05:46:05 -0800 (PST) From: Bryan O'Donoghue To: libcamera-devel@lists.libcamera.org Cc: pavel@ucw.cz, Bryan O'Donoghue , Milan Zamazal Subject: [PATCH v6 10/24] libcamera: shaders: Add support for contrast Date: Tue, 2 Dec 2025 13:45:30 +0000 Message-ID: <20251202134544.662446-11-bryan.odonoghue@linaro.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251202134544.662446-1-bryan.odonoghue@linaro.org> References: <20251202134544.662446-1-bryan.odonoghue@linaro.org> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Apply contrast after black-level and CCM operations. Suggested-by: Milan Zamazal Signed-off-by: Bryan O'Donoghue --- src/libcamera/shaders/bayer_1x_packed.frag | 19 +++++++++++++++++++ src/libcamera/shaders/bayer_unpacked.frag | 19 +++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag index 77d9fbfa7..2fc9952e2 100644 --- a/src/libcamera/shaders/bayer_1x_packed.frag +++ b/src/libcamera/shaders/bayer_1x_packed.frag @@ -68,6 +68,19 @@ uniform sampler2D tex_y; uniform mat3 ccm; uniform vec3 blacklevel; uniform float gamma; +uniform float contrast; + +float apply_contrast(float normalise, float contrast_in) +{ + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) + float contrastExp = tan(clamp(contrast_in * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); + + // Apply simple S-curve + if (normalise < 0.5) + return 0.5 * pow(normalise / 0.5, contrastExp); + else + return 1.0 - 0.5 * pow((1.0 - normalise) / 0.5, contrastExp); +} void main(void) { @@ -261,6 +274,12 @@ void main(void) rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); + /* Contrast */ + rgb = clamp(rgb, 0.0, 1.0); + rgb.r = apply_contrast(rgb.r, contrast); + rgb.g = apply_contrast(rgb.g, contrast); + rgb.b = apply_contrast(rgb.b, contrast); + /* Apply gamma after colour correction */ rgb = pow(rgb, vec3(gamma)); diff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag index aba11a87f..caa0ba15d 100644 --- a/src/libcamera/shaders/bayer_unpacked.frag +++ b/src/libcamera/shaders/bayer_unpacked.frag @@ -27,6 +27,19 @@ varying vec4 xCoord; uniform mat3 ccm; uniform vec3 blacklevel; uniform float gamma; +uniform float contrast; + +float apply_contrast(float normalise, float contrast_in) +{ + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) + float contrastExp = tan(clamp(contrast_in * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); + + // Apply simple S-curve + if (normalise < 0.5) + return 0.5 * pow(normalise / 0.5, contrastExp); + else + return 1.0 - 0.5 * pow((1.0 - normalise) / 0.5, contrastExp); +} void main(void) { vec3 rgb; @@ -156,6 +169,12 @@ void main(void) { rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); + /* Contrast */ + rgb = clamp(rgb, 0.0, 1.0); + rgb.r = apply_contrast(rgb.r, contrast); + rgb.g = apply_contrast(rgb.g, contrast); + rgb.b = apply_contrast(rgb.b, contrast); + /* Apply gamma after colour correction */ rgb = pow(rgb, vec3(gamma));