From patchwork Wed Jul 8 14:14:28 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 27301 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 4F35BC3306 for ; Wed, 8 Jul 2026 14:14:51 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 12CDE66089; Wed, 8 Jul 2026 16:14:50 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="YP87j+B6"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id CCF4765FF1 for ; Wed, 8 Jul 2026 16:14:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783520086; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=fLXqOU7RmRd0+PY3n/eGW5KC/m6P5LSAPnJxhGVgQTk=; b=YP87j+B6/20Kmn6xrq22t4PHzFt7+9SyNGdN/uin/DBYYNi5XVq65FOU7r0mhhYE9kgyFO IusTR77dQDbIXmsfzn0HIDKSCHc/EQURrtTrd0BabF5toOdjFHsBUpUiITblHnjE+4i7rs NZmc98GbL6hwdLY8K5x9b6wrWcJsOCE= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-125-YzajMsMjPyeB_jDUVLI-DQ-1; Wed, 08 Jul 2026 10:14:45 -0400 X-MC-Unique: YzajMsMjPyeB_jDUVLI-DQ-1 X-Mimecast-MFC-AGG-ID: YzajMsMjPyeB_jDUVLI-DQ_1783520084 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 57BD41955D87; Wed, 8 Jul 2026 14:14:43 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.48.228]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D3BC13EEDE; Wed, 8 Jul 2026 14:14:40 +0000 (UTC) From: Milan Zamazal To: libcamera-devel@lists.libcamera.org Cc: Milan Zamazal , Bryan O'Donoghue , Hans de Goede , Laurent Pinchart Subject: [RFC PATCH v6 0/6] LSC for SoftISP simple pipeline Date: Wed, 8 Jul 2026 16:14:28 +0200 Message-ID: <20260708141436.119165-1-mzamazal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: hPKdx3cMKmBjsxyNngyAbkeRa9s-iCxyqbnL5nI6ARo_1783520084 X-Mimecast-Originator: redhat.com 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" Lens shading correction for software GPU ISP. Based on the initial work by Hans’s students, taken over and significantly modified and eventually reworked to use LSC from libipa (the ongoing work by Jacopo and others). The LSC is not implemented for CPU ISP within this series; it may be added later if needed. It’s RFC because: - It’s not yet completely tested although it seems to be working in my environment. - It’s based on the libipa patches not yet merged. - Further changes will be needed once GPU ISP multipass is merged. Changes in v6: - Rebased on Jacopo’s libipa patches (v3). - Not updating LSC tables on small or no temperature changes. - Using libipa LSC algorithms; the implementation in ‘simple’ IPA algorithm reduced to the minimum needed. - Grid tables are defined using integers rather than floats, because libipa LSC supports only quantised values and not floats. - New boolean uniform to enable or disable LSC dynamically, rather than only in shaders compile time; to be able to honour the LSC control. - Specific handling of polynomial LSC removed. Polynomial LSC is already handled by libipa, by making a grid-based LSC from it. While a direct polynomial computation may be a bit faster with a minimum number of the polynomial coefficients, the simplicity wins. If we liked to have direct polynomial LSC computation, it should be implemented with help of libipa. Changes in v5: - ‘grids’ tuning file item renamed to ‘sets’ for consistency with rkisp1. - Underscores appended to Lsc::lsc* names. - Other minor stylistic changes. - Proof-of-concept polynomial LSC implemented. Changes in v4: - glFilterParam -> param - Indentation changes in the shaders. - A commit message part about temperature reworded. - Updated for YamlObject -> ValueNode. - New constant kLscValuesPerCell to distinguish between the constants for the params array size (values) and for the stride (bytes). - The lookup array switched to floats and the texture to half-floats. Changes in v3: - LSC scripts patch dropped due to missing licences. - DO_LSC -> APPLY_LSC - textureUniformLsc_ is assigned unconditionally now. - New constant DebayerParams::kLscBytesPerCell. - LSC values in the tuning file are floats now and converted to bytes internally. - Source code comments added to clarify the usage of the byte LUTs. Changes in v2: - Remaining issues from the reviews (hopefully) addressed. - Especially there is only a single texture now and LSC is fully conditional. - Major cleanup, hacks removed or replaced, typo fixes, cosmetic changes, making linters happy, etc. - See https://lists.libcamera.org/pipermail/libcamera-devel/2026-January/056883.html for an example how to add the grid data. Milan Zamazal (1): libcamera: software_isp: Pass LSC availability to debayering Xander Pronk (5): libcamera: software_isp: egl: Add filter parameter to createTexture2D() libcamera: software_isp: Add LSC data to DebayerParams ipa: simple: Add LSC algorithm libcamera: shaders: Add LSC support libcamera: software_isp: debayer_egl: Add LSC support include/libcamera/internal/egl.h | 6 +- .../internal/software_isp/debayer_params.h | 11 +++ .../internal/software_isp/software_isp.h | 1 + include/libcamera/ipa/soft.mojom | 4 +- src/ipa/simple/algorithms/lsc.cpp | 93 +++++++++++++++++++ src/ipa/simple/algorithms/lsc.h | 50 ++++++++++ src/ipa/simple/algorithms/meson.build | 1 + src/ipa/simple/ipa_context.h | 6 ++ src/ipa/simple/soft_simple.cpp | 7 +- src/libcamera/egl.cpp | 17 +++- src/libcamera/shaders/bayer_1x_packed.frag | 10 ++ src/libcamera/shaders/bayer_unpacked.frag | 10 ++ src/libcamera/software_isp/debayer.cpp | 39 ++++++++ src/libcamera/software_isp/debayer.h | 3 +- src/libcamera/software_isp/debayer_cpu.cpp | 3 +- src/libcamera/software_isp/debayer_cpu.h | 3 +- src/libcamera/software_isp/debayer_egl.cpp | 37 +++++++- src/libcamera/software_isp/debayer_egl.h | 11 ++- src/libcamera/software_isp/software_isp.cpp | 5 +- 19 files changed, 299 insertions(+), 18 deletions(-) create mode 100644 src/ipa/simple/algorithms/lsc.cpp create mode 100644 src/ipa/simple/algorithms/lsc.h