libcamera::ipa::ipu3::algorithms::Agc Class Reference

A mean-based auto-exposure algorithm. More...

Inheritance diagram for libcamera::ipa::ipu3::algorithms::Agc:

Collaboration diagram for libcamera::ipa::ipu3::algorithms::Agc:

Public Member Functions
int	configure (IPAContext &context, const IPAConfigInfo &configInfo) override
	Configure the AGC given a configInfo. More...
void	process (IPAContext &context, const uint32_t frame, IPAFrameContext &frameContext, const ipu3_uapi_stats_3a *stats, ControlList &metadata) override
	Process IPU3 statistics, and run AGC operations. More...
Public Member Functions inherited from libcamera::ipa::Algorithm< _Module >
virtual int	init (typename Module::Context &context, const YamlObject &tuningData)
	Initialize the Algorithm with tuning data. More...
virtual int	configure (typename Module::Context &context, const typename Module::Config &configInfo)
	Configure the Algorithm given an IPAConfigInfo. More...
virtual void	queueRequest (typename Module::Context &context, const uint32_t frame, typename Module::FrameContext &frameContext, const ControlList &controls)
	Provide control values to the algorithm. More...
virtual void	prepare (typename Module::Context &context, const uint32_t frame, typename Module::FrameContext &frameContext, typename Module::Params *params)
	Fill the params buffer with ISP processing parameters for a frame. More...
virtual void	process (typename Module::Context &context, const uint32_t frame, typename Module::FrameContext &frameContext, const typename Module::Stats *stats, ControlList &metadata)
	Process ISP statistics, and run algorithm operations. More...

Additional Inherited Members
Public Types inherited from libcamera::ipa::Algorithm< _Module >
using	Module = _Module
	The IPA module type for this class of algorithms.

Detailed Description

A mean-based auto-exposure algorithm.

This algorithm calculates a shutter time and an analogue gain so that the average value of the green channel of the brightest 2% of pixels approaches 0.5. The AWB gains are not used here, and all cells in the grid have the same weight, like an average-metering case. In this metering mode, the camera uses light information from the entire scene and creates an average for the final exposure setting, giving no weighting to any particular portion of the metered area.

Reference: Battiato, Messina & Castorina. (2008). Exposure Correction for Imaging Devices: An Overview. 10.1201/9781420054538.ch12.

Member Function Documentation

configure()

int libcamera::ipa::ipu3::algorithms::Agc::configure ( IPAContext &  context, const IPAConfigInfo &  configInfo  )

override

Configure the AGC given a configInfo.

Parameters

[in]	context	The shared IPA context
[in]	configInfo	The IPA configuration data

Returns

0

process()

void libcamera::ipa::ipu3::algorithms::Agc::process ( IPAContext &  context, const uint32_t  frame, IPAFrameContext &  frameContext, const ipu3_uapi_stats_3a *  stats, ControlList &  metadata  )

override

Process IPU3 statistics, and run AGC operations.

Parameters

[in]	context	The shared IPA context
[in]	frame	The current frame sequence number
[in]	frameContext	The current frame context
[in]	stats	The IPU3 statistics and ISP results
[out]	metadata	Metadata for the frame, to be filled by the algorithm

Identify the current image brightness, and use that to estimate the optimal new exposure and gain for the scene.

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The documentation for this class was generated from the following files:

• src/ipa/ipu3/algorithms/agc.h
• src/ipa/ipu3/algorithms/agc.cpp