libcamera/libcamera.git - libcamera official repository

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author	Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>	2021-09-06 16:02:51 +0200
committer	Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>	2021-10-26 14:02:19 +0200
commit	346baa856bbd458ad408a4c021e768a66ab7728f (patch)
tree	56e0868a8969b0e455417c07cd1312a9e565d8ef /utils/raspberrypi/ctt/ctt_noise.py
parent	b1cefe38f360915ad597ab2934c009bd1e46d10d (diff)

ipa: ipu3: Document IPAIPU3 class interface

The IPU3 IPA is maturing to a modular and extensible system capable of handling specific algorithms for the processing blocks on the ImgU. Provide a top-level class documentation to provide an overview of the IPA, detailing what events are used and what algorithms are currently supported, as well as the limitations currently imposed. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

Diffstat (limited to 'utils/raspberrypi/ctt/ctt_noise.py')

0 files changed, 0 insertions, 0 deletions

/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi (Trading) Limited * * contrast.cpp - contrast (gamma) control algorithm */ #include <stdint.h> #include "../contrast_status.h" #include "../histogram.hpp" #include "contrast.hpp" using namespace RPiController; // This is a very simple control algorithm which simply retrieves the results of // AGC and AWB via their "status" metadata, and applies digital gain to the // colour channels in accordance with those instructions. We take care never to // apply less than unity gains, as that would cause fully saturated pixels to go // off-white. #define NAME "rpi.contrast" Contrast::Contrast(Controller *controller) : ContrastAlgorithm(controller), brightness_(0.0), contrast_(1.0) { } char const *Contrast::Name() const { return NAME; } void Contrast::Read(boost::property_tree::ptree const &params) { // enable adaptive enhancement by default config_.ce_enable = params.get<int>("ce_enable", 1); // the point near the bottom of the histogram to move config_.lo_histogram = params.get<double>("lo_histogram", 0.01); // where in the range to try and move it to config_.lo_level = params.get<double>("lo_level", 0.015); // but don't move by more than this config_.lo_max = params.get<double>("lo_max", 500); // equivalent values for the top of the histogram... config_.hi_histogram = params.get<double>("hi_histogram", 0.95); config_.hi_level = params.get<double>("hi_level", 0.95); config_.hi_max = params.get<double>("hi_max", 2000); config_.gamma_curve.Read(params.get_child("gamma_curve")); } void Contrast::SetBrightness(double brightness) { brightness_ = brightness; } void Contrast::SetContrast(double contrast) { contrast_ = contrast; } static void fill_in_status(ContrastStatus &status, double brightness, double contrast, Pwl &gamma_curve) { status.brightness = brightness; status.contrast = contrast; for (int i = 0; i < CONTRAST_NUM_POINTS - 1; i++) { int x = i < 16 ? i * 1024 : (i < 24 ? (i - 16) * 2048 + 16384 : (i - 24) * 4096 + 32768); status.points[i].x = x; status.points[i].y = std::min(65535.0, gamma_curve.Eval(x)); } status.points[CONTRAST_NUM_POINTS - 1].x = 65535; status.points[CONTRAST_NUM_POINTS - 1].y = 65535; } void Contrast::Initialise() { // Fill in some default values as Prepare will run before Process gets // called. fill_in_status(status_, brightness_, contrast_, config_.gamma_curve); } void Contrast::Prepare(Metadata *image_metadata) { std::unique_lock<std::mutex> lock(mutex_); image_metadata->Set("contrast.status", status_); } Pwl compute_stretch_curve(Histogram const &histogram, ContrastConfig const &config) { Pwl enhance; enhance.Append(0, 0); // If the start of the histogram is rather empty, try to pull it down a // bit. double hist_lo = histogram.Quantile(config.lo_histogram) * (65536 / NUM_HISTOGRAM_BINS); double level_lo = config.lo_level * 65536; RPI_LOG("Move histogram point " << hist_lo << " to " << level_lo); hist_lo = std::max( level_lo, std::min(65535.0, std::min(hist_lo, level_lo + config.lo_max))); RPI_LOG("Final values " << hist_lo << " -> " << level_lo); enhance.Append(hist_lo, level_lo); // Keep the mid-point (median) in the same place, though, to limit the // apparent amount of global brightness shift. double mid = histogram.Quantile(0.5) * (65536 / NUM_HISTOGRAM_BINS); enhance.Append(mid, mid); // If the top to the histogram is empty, try to pull the pixel values // there up. double hist_hi = histogram.Quantile(config.hi_histogram) * (65536 / NUM_HISTOGRAM_BINS); double level_hi = config.hi_level * 65536; RPI_LOG("Move histogram point " << hist_hi << " to " << level_hi); hist_hi = std::min( level_hi, std::max(0.0, std::max(hist_hi, level_hi - config.hi_max))); RPI_LOG("Final values " << hist_hi << " -> " << level_hi); enhance.Append(hist_hi, level_hi); enhance.Append(65535, 65535); return enhance; } Pwl apply_manual_contrast(Pwl const &gamma_curve, double brightness, double contrast) { Pwl new_gamma_curve; RPI_LOG("Manual brightness " << brightness << " contrast " << contrast); gamma_curve.Map([&](double x, double y) { new_gamma_curve.Append( x, std::max(0.0, std::min(65535.0, (y - 32768) * contrast + 32768 + brightness))); }); return new_gamma_curve; } void Contrast::Process(StatisticsPtr &stats, [[maybe_unused]] Metadata *image_metadata) { double brightness = brightness_, contrast = contrast_; Histogram histogram(stats->hist[0].g_hist, NUM_HISTOGRAM_BINS); // We look at the histogram and adjust the gamma curve in the following // ways: 1. Adjust the gamma curve so as to pull the start of the // histogram down, and possibly push the end up. Pwl gamma_curve = config_.gamma_curve; if (config_.ce_enable) { if (config_.lo_max != 0 || config_.hi_max != 0) gamma_curve = compute_stretch_curve(histogram, config_) .Compose(gamma_curve); // We could apply other adjustments (e.g. partial equalisation) // based on the histogram...? } // 2. Finally apply any manually selected brightness/contrast // adjustment. if (brightness != 0 || contrast != 1.0) gamma_curve = apply_manual_contrast(gamma_curve, brightness, contrast); // And fill in the status for output. Use more points towards the bottom // of the curve. ContrastStatus status; fill_in_status(status, brightness, contrast, gamma_curve); { std::unique_lock<std::mutex> lock(mutex_); status_ = status; } } // Register algorithm with the system. static Algorithm *Create(Controller *controller) { return (Algorithm *)new Contrast(controller); } static RegisterAlgorithm reg(NAME, &Create);


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