From patchwork Wed Mar 23 16:01:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Michel Hautbois X-Patchwork-Id: 15527 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 9F40BC3264 for ; Wed, 23 Mar 2022 16:01:55 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 14CA4604E8; Wed, 23 Mar 2022 17:01:53 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org; s=mail; t=1648051313; bh=hAYcoqx5KqhNup/OmO2+ilIeuLssAinCiaas26Uw+ww=; h=To:Date:In-Reply-To:References:Subject:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=San467JobppGUaGHSNU0L7svNqPDlciZwYxSG/9gH9iqgUyynK3unrnFj4MXWk5Vb 9G9pz8KGA83sSwTBpOM2mWVKcbjZy9gk4kGzIa+MXF/G5Q+CbYqo3vxEciRUsromeW 962AepVMG+SZtNLmFQrafeLNZYbQOcmjkUaFRxv2+Ct5ZNBobuqaLEtYAjcRWp8WnB AOvXVbYSAVeMPXBtqEWV83bzKW+mthKiXf0VbNl+nmjN1cGi9ikEjZVaGBZAj+YkOu oMH5+v1F2KjsVkuEFEL7dQu7W7lWPJjv2ZFpiphcgQt7MXI7VHQVEgMJUkmnhbumYU fjpsbT8X6w/DA== Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id CF079604D5 for ; Wed, 23 Mar 2022 17:01:49 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="R8UQ1d+n"; dkim-atps=neutral Received: from tatooine.ideasonboard.com (unknown [IPv6:2a01:e0a:169:7140:2e05:b10:1542:d51b]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 7D883130D; Wed, 23 Mar 2022 17:01:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1648051309; bh=hAYcoqx5KqhNup/OmO2+ilIeuLssAinCiaas26Uw+ww=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R8UQ1d+n0gEVHBxdny4OO82oSi/91dq1F/QBk0DgQnjPw0wdZvQyU5gPmK3Y958zw HPNbBi2C3YW/DMXGne88J/QkzIHJ7ekCvnrnVvNqmTdfXiuRYS/XBNXAHcaWDjVJof IZOHFTexUsU48HolvKH5Ha8wSpOzoKbwQmjpQtVI= To: libcamera-devel@lists.libcamera.org Date: Wed, 23 Mar 2022 17:01:43 +0100 Message-Id: <20220323160145.90606-3-jeanmichel.hautbois@ideasonboard.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220323160145.90606-1-jeanmichel.hautbois@ideasonboard.com> References: <20220323160145.90606-1-jeanmichel.hautbois@ideasonboard.com> MIME-Version: 1.0 Subject: [libcamera-devel] [RFC PATCH v2 2/4] ipa: raspberrypi: Introduce an autofocus algorithm 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: , X-Patchwork-Original-From: Jean-Michel Hautbois via libcamera-devel From: Jean-Michel Hautbois Reply-To: Jean-Michel Hautbois Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Now that the ancillary links are plumbed and we can set the lens position, implement a contrast-based algorithm for RPi. This algorithm is adapted from the one proposed for the IPU3 IPA. It is currently taking all the regions and tries to make the focus on the global scene in a first attempt. Signed-off-by: Jean-Michel Hautbois --- .../raspberrypi/controller/af_algorithm.hpp | 20 ++ src/ipa/raspberrypi/controller/af_status.h | 31 +++ src/ipa/raspberrypi/controller/focus_status.h | 3 + src/ipa/raspberrypi/controller/iob/af.cpp | 231 ++++++++++++++++++ src/ipa/raspberrypi/controller/iob/af.h | 55 +++++ src/ipa/raspberrypi/meson.build | 1 + 6 files changed, 341 insertions(+) create mode 100644 src/ipa/raspberrypi/controller/af_algorithm.hpp create mode 100644 src/ipa/raspberrypi/controller/af_status.h create mode 100644 src/ipa/raspberrypi/controller/iob/af.cpp create mode 100644 src/ipa/raspberrypi/controller/iob/af.h diff --git a/src/ipa/raspberrypi/controller/af_algorithm.hpp b/src/ipa/raspberrypi/controller/af_algorithm.hpp new file mode 100644 index 00000000..553a37e1 --- /dev/null +++ b/src/ipa/raspberrypi/controller/af_algorithm.hpp @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2019, Raspberry Pi (Trading) Limited + * + * af_algorithm.hpp - autofocus control algorithm interface + */ +#pragma once + +#include "algorithm.hpp" + +namespace RPiController { + +class AfAlgorithm : public Algorithm +{ +public: + AfAlgorithm(Controller *controller) : Algorithm(controller) {} + // An af algorithm must provide the following: +}; + +} // namespace RPiController diff --git a/src/ipa/raspberrypi/controller/af_status.h b/src/ipa/raspberrypi/controller/af_status.h new file mode 100644 index 00000000..835e1e2f --- /dev/null +++ b/src/ipa/raspberrypi/controller/af_status.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2020, Raspberry Pi (Trading) Limited + * Copyright (C) 2022, Ideas On Board + * + * af_status.h - autofocus measurement status + */ +#pragma once + +#include + +/* + * The focus algorithm should post the following structure into the image's + * "af.status" metadata. + */ + +#ifdef __cplusplus +extern "C" { +#endif + +struct AfStatus { + unsigned int num; + uint32_t focus_measures[FOCUS_REGIONS]; + bool stable; + uint32_t focus; + double maxVariance; +}; + +#ifdef __cplusplus +} +#endif diff --git a/src/ipa/raspberrypi/controller/focus_status.h b/src/ipa/raspberrypi/controller/focus_status.h index ace2fe2c..8122df4b 100644 --- a/src/ipa/raspberrypi/controller/focus_status.h +++ b/src/ipa/raspberrypi/controller/focus_status.h @@ -19,6 +19,9 @@ extern "C" { struct FocusStatus { unsigned int num; uint32_t focus_measures[FOCUS_REGIONS]; + bool stable; + uint32_t focus; + double maxVariance; }; #ifdef __cplusplus diff --git a/src/ipa/raspberrypi/controller/iob/af.cpp b/src/ipa/raspberrypi/controller/iob/af.cpp new file mode 100644 index 00000000..dc5258ba --- /dev/null +++ b/src/ipa/raspberrypi/controller/iob/af.cpp @@ -0,0 +1,231 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2021, Red Hat + * Copyright (C) 2022, Ideas On Board + * + * af.cpp - automatic contrast-based focus algorithm + */ +#include + +#include + +#include + +#include "af.h" + +using namespace RPiController; +using namespace libcamera; + +LOG_DEFINE_CATEGORY(IoBAf) + +#define NAME "iob.af" + +/* + * Maximum focus steps of the VCM control + * \todo should be obtained from the VCM driver + */ +static constexpr uint32_t kMaxFocusSteps = 1023; + +/* Minimum focus step for searching appropriate focus */ +static constexpr uint32_t kCoarseSearchStep = 30; +static constexpr uint32_t kFineSearchStep = 1; + +/* Max ratio of variance change, 0.0 < kMaxChange < 1.0 */ +static constexpr double kMaxChange = 0.5; + +/* The numbers of frame to be ignored, before performing focus scan. */ +static constexpr uint32_t kIgnoreFrame = 10; + +/* Fine scan range 0 < kFineRange < 1 */ +static constexpr double kFineRange = 0.05; + +Af::Af(Controller *controller) + : AfAlgorithm(controller), focus_(0), bestFocus_(0), ignoreCounter_(0), + currentVariance_(0.0), previousVariance_(0.0), maxStep_(0), + coarseCompleted_(false), fineCompleted_(false) +{ +} + +char const *Af::Name() const +{ + return NAME; +} + +void Af::Initialise() +{ + status_.focus = 0.0; + status_.maxVariance = 0.0; + status_.stable = false; +} + +void Af::Prepare(Metadata *image_metadata) +{ + image_metadata->Set("af.status", status_); +} + +double Af::estimateVariance() +{ + unsigned int i; + double mean; + uint64_t total = 0; + double var_sum = 0.0; + + /* Compute the mean value. */ + for (i = 0; i < FOCUS_REGIONS; i++) + total += status_.focus_measures[i]; + mean = total / FOCUS_REGIONS; + + /* Compute the sum of the squared variance. */ + for (i = 0; i < FOCUS_REGIONS; i++) + var_sum += std::pow(status_.focus_measures[i] - mean, 2); + + return var_sum / FOCUS_REGIONS; +} + +bool Af::afNeedIgnoreFrame() +{ + if (ignoreCounter_ == 0) + return false; + else + ignoreCounter_--; + return true; +} + +void Af::afCoarseScan() +{ + if (coarseCompleted_) + return; + + if (afNeedIgnoreFrame()) + return; + + if (afScan(kCoarseSearchStep)) { + coarseCompleted_ = true; + status_.maxVariance = 0; + focus_ = status_.focus - (status_.focus * kFineRange); + status_.focus = focus_; + previousVariance_ = 0; + maxStep_ = std::clamp(focus_ + static_cast((focus_ * kFineRange)), + 0U, kMaxFocusSteps); + } +} + +void Af::afFineScan() +{ + if (!coarseCompleted_) + return; + + if (afNeedIgnoreFrame()) + return; + + if (afScan(kFineSearchStep)) { + status_.stable = true; + fineCompleted_ = true; + } +} + +bool Af::afScan(uint32_t minSteps) +{ + if (focus_ > maxStep_) { + /* If the max step is reached, move lens to the position. */ + status_.focus = bestFocus_; + return true; + } else { + /* + * Find the maximum of the variance by estimating its + * derivative. If the direction changes, it means we have passed + * a maximum one step before. + */ + if ((currentVariance_ - status_.maxVariance) >= + -(status_.maxVariance * 0.1)) { + /* + * Positive and zero derivative: + * The variance is still increasing. The focus could be + * increased for the next comparison. Also, the max + * variance and previous focus value are updated. + */ + bestFocus_ = focus_; + focus_ += minSteps; + status_.focus = focus_; + status_.maxVariance = currentVariance_; + } else { + /* + * Negative derivative: + * The variance starts to decrease which means the maximum + * variance is found. Set focus step to previous good one + * then return immediately. + */ + status_.focus = bestFocus_; + return true; + } + } + + previousVariance_ = currentVariance_; + LOG(IoBAf, Debug) << " Previous step is " + << bestFocus_ + << " Current step is " + << focus_; + return false; +} + +void Af::afReset() +{ + if (afNeedIgnoreFrame()) + return; + + status_.maxVariance = 0; + status_.focus = 0; + focus_ = 0; + status_.stable = false; + ignoreCounter_ = kIgnoreFrame; + previousVariance_ = 0.0; + coarseCompleted_ = false; + fineCompleted_ = false; + maxStep_ = kMaxFocusSteps; +} + +bool Af::afIsOutOfFocus() +{ + const uint32_t diff_var = std::abs(currentVariance_ - + status_.maxVariance); + const double var_ratio = diff_var / status_.maxVariance; + LOG(IoBAf, Debug) << "Variance change rate: " + << var_ratio + << " Current VCM step: " + << status_.focus; + if (var_ratio > kMaxChange) + return true; + else + return false; +} + +void Af::Process(StatisticsPtr &stats, Metadata *image_metadata) +{ + unsigned int i; + image_metadata->Get("af.status", status_); + + /* Use the second filter results only, and cache those. */ + for (i = 0; i < FOCUS_REGIONS; i++) + status_.focus_measures[i] = stats->focus_stats[i].contrast_val[1][1] + / stats->focus_stats[i].contrast_val_num[1][1]; + status_.num = i; + + currentVariance_ = estimateVariance(); + + if (!status_.stable) { + afCoarseScan(); + afFineScan(); + } else { + if (afIsOutOfFocus()) + afReset(); + else + ignoreCounter_ = kIgnoreFrame; + } +} + +/* Register algorithm with the system. */ +static Algorithm *Create(Controller *controller) +{ + return new Af(controller); +} +static RegisterAlgorithm reg(NAME, &Create); diff --git a/src/ipa/raspberrypi/controller/iob/af.h b/src/ipa/raspberrypi/controller/iob/af.h new file mode 100644 index 00000000..45c9711f --- /dev/null +++ b/src/ipa/raspberrypi/controller/iob/af.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2021, Red Hat + * Copyright (C) 2022, Ideas On Board + * + * af.h - automatic contrast-based focus algorithm + */ +#pragma once + +#include "../af_algorithm.hpp" +#include "../af_status.h" +#include "../metadata.hpp" + +namespace RPiController { + +class Af : public AfAlgorithm +{ +public: + Af(Controller *controller); + char const *Name() const override; + void Initialise() override; + void Prepare(Metadata *image_metadata) override; + void Process(StatisticsPtr &stats, Metadata *image_metadata) override; +private: + double estimateVariance(); + bool afNeedIgnoreFrame(); + void afCoarseScan(); + void afFineScan(); + bool afScan(uint32_t minSteps); + void afReset(); + bool afIsOutOfFocus(); + + AfStatus status_; + + /* VCM step configuration. It is the current setting of the VCM step. */ + uint32_t focus_; + /* The best VCM step. It is a local optimum VCM step during scanning. */ + uint32_t bestFocus_; + + /* The frames ignored before starting measuring. */ + uint32_t ignoreCounter_; + + /* Current AF statistic variance. */ + double currentVariance_; + /* It is used to determine the derivative during scanning */ + double previousVariance_; + /* The designated maximum range of focus scanning. */ + uint32_t maxStep_; + /* If the coarse scan completes, it is set to true. */ + bool coarseCompleted_; + /* If the fine scan completes, it is set to true. */ + bool fineCompleted_; +}; + +} /* namespace RPiController */ diff --git a/src/ipa/raspberrypi/meson.build b/src/ipa/raspberrypi/meson.build index 32897e07..37068ecc 100644 --- a/src/ipa/raspberrypi/meson.build +++ b/src/ipa/raspberrypi/meson.build @@ -28,6 +28,7 @@ rpi_ipa_sources = files([ 'controller/controller.cpp', 'controller/histogram.cpp', 'controller/algorithm.cpp', + 'controller/iob/af.cpp', 'controller/rpi/alsc.cpp', 'controller/rpi/awb.cpp', 'controller/rpi/sharpen.cpp',