| Message ID | 20240322131451.3092931-8-dan.scally@ideasonboard.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
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| Related | show |
Hi Daniel, looks good to me. Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com> Cheers, Stefan On Fri, Mar 22, 2024 at 01:14:48PM +0000, Daniel Scally wrote: > Now that the IPU3's Agc is derived from MeanLuminanceAgc we can > delete all the unecessary bespoke functions. > > Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> > --- > src/ipa/ipu3/algorithms/agc.cpp | 241 -------------------------------- > src/ipa/ipu3/algorithms/agc.h | 13 -- > 2 files changed, 254 deletions(-) > > diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp > index a84534ea..08deff0c 100644 > --- a/src/ipa/ipu3/algorithms/agc.cpp > +++ b/src/ipa/ipu3/algorithms/agc.cpp > @@ -132,8 +132,6 @@ int Agc::configure(IPAContext &context, > activeState.agc.gain = minAnalogueGain_; > activeState.agc.exposure = 10ms / configuration.sensor.lineDuration; > > - frameCount_ = 0; > - > /* > * \todo We should use the first available mode rather than assume that > * the "Normal" modes are present in tuning data. > @@ -150,42 +148,6 @@ int Agc::configure(IPAContext &context, > return 0; > } > > -/** > - * \brief Estimate the mean value of the top 2% of the histogram > - * \param[in] stats The statistics computed by the ImgU > - * \param[in] grid The grid used to store the statistics in the IPU3 > - * \return The mean value of the top 2% of the histogram > - */ > -double Agc::measureBrightness(const ipu3_uapi_stats_3a *stats, > - const ipu3_uapi_grid_config &grid) const > -{ > - /* Initialise the histogram array */ > - uint32_t hist[knumHistogramBins] = { 0 }; > - > - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { > - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { > - uint32_t cellPosition = cellY * stride_ + cellX; > - > - const ipu3_uapi_awb_set_item *cell = > - reinterpret_cast<const ipu3_uapi_awb_set_item *>( > - &stats->awb_raw_buffer.meta_data[cellPosition] > - ); > - > - uint8_t gr = cell->Gr_avg; > - uint8_t gb = cell->Gb_avg; > - /* > - * Store the average green value to estimate the > - * brightness. Even the overexposed pixels are > - * taken into account. > - */ > - hist[(gr + gb) / 2]++; > - } > - } > - > - /* Estimate the quantile mean of the top 2% of the histogram. */ > - return Histogram(Span<uint32_t>(hist)).interQuantileMean(0.98, 1.0); > -} > - > void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, > const ipu3_uapi_grid_config &grid) > { > @@ -219,173 +181,6 @@ void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, > hist_ = Histogram(Span<uint32_t>(hist)); > } > > -/** > - * \brief Apply a filter on the exposure value to limit the speed of changes > - * \param[in] exposureValue The target exposure from the AGC algorithm > - * > - * The speed of the filter is adaptive, and will produce the target quicker > - * during startup, or when the target exposure is within 20% of the most recent > - * filter output. > - * > - * \return The filtered exposure > - */ > -utils::Duration Agc::filterExposure(utils::Duration exposureValue) > -{ > - double speed = 0.2; > - > - /* Adapt instantly if we are in startup phase. */ > - if (frameCount_ < kNumStartupFrames) > - speed = 1.0; > - > - /* > - * If we are close to the desired result, go faster to avoid making > - * multiple micro-adjustments. > - * \todo Make this customisable? > - */ > - if (filteredExposure_ < 1.2 * exposureValue && > - filteredExposure_ > 0.8 * exposureValue) > - speed = sqrt(speed); > - > - filteredExposure_ = speed * exposureValue + > - filteredExposure_ * (1.0 - speed); > - > - LOG(IPU3Agc, Debug) << "After filtering, exposure " << filteredExposure_; > - > - return filteredExposure_; > -} > - > -/** > - * \brief Estimate the new exposure and gain values > - * \param[inout] frameContext The shared IPA frame Context > - * \param[in] yGain The gain calculated based on the relative luminance target > - * \param[in] iqMeanGain The gain calculated based on the relative luminance target > - */ > -void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, > - double yGain, double iqMeanGain) > -{ > - const IPASessionConfiguration &configuration = context.configuration; > - /* Get the effective exposure and gain applied on the sensor. */ > - uint32_t exposure = frameContext.sensor.exposure; > - double analogueGain = frameContext.sensor.gain; > - > - /* Use the highest of the two gain estimates. */ > - double evGain = std::max(yGain, iqMeanGain); > - > - /* Consider within 1% of the target as correctly exposed */ > - if (utils::abs_diff(evGain, 1.0) < 0.01) > - LOG(IPU3Agc, Debug) << "We are well exposed (evGain = " > - << evGain << ")"; > - > - /* extracted from Rpi::Agc::computeTargetExposure */ > - > - /* Calculate the shutter time in seconds */ > - utils::Duration currentShutter = exposure * configuration.sensor.lineDuration; > - > - /* > - * Update the exposure value for the next computation using the values > - * of exposure and gain really used by the sensor. > - */ > - utils::Duration effectiveExposureValue = currentShutter * analogueGain; > - > - LOG(IPU3Agc, Debug) << "Actual total exposure " << currentShutter * analogueGain > - << " Shutter speed " << currentShutter > - << " Gain " << analogueGain > - << " Needed ev gain " << evGain; > - > - /* > - * Calculate the current exposure value for the scene as the latest > - * exposure value applied multiplied by the new estimated gain. > - */ > - utils::Duration exposureValue = effectiveExposureValue * evGain; > - > - /* Clamp the exposure value to the min and max authorized */ > - utils::Duration maxTotalExposure = maxShutterSpeed_ * maxAnalogueGain_; > - exposureValue = std::min(exposureValue, maxTotalExposure); > - LOG(IPU3Agc, Debug) << "Target total exposure " << exposureValue > - << ", maximum is " << maxTotalExposure; > - > - /* > - * Filter the exposure. > - * \todo estimate if we need to desaturate > - */ > - exposureValue = filterExposure(exposureValue); > - > - /* > - * Divide the exposure value as new exposure and gain values. > - * > - * Push the shutter time up to the maximum first, and only then > - * increase the gain. > - */ > - utils::Duration shutterTime = > - std::clamp<utils::Duration>(exposureValue / minAnalogueGain_, > - minShutterSpeed_, maxShutterSpeed_); > - double stepGain = std::clamp(exposureValue / shutterTime, > - minAnalogueGain_, maxAnalogueGain_); > - LOG(IPU3Agc, Debug) << "Divided up shutter and gain are " > - << shutterTime << " and " > - << stepGain; > -} > - > -/** > - * \brief Estimate the relative luminance of the frame with a given gain > - * \param[in] frameContext The shared IPA frame context > - * \param[in] grid The grid used to store the statistics in the IPU3 > - * \param[in] stats The IPU3 statistics and ISP results > - * \param[in] gain The gain to apply to the frame > - * \return The relative luminance > - * > - * This function estimates the average relative luminance of the frame that > - * would be output by the sensor if an additional \a gain was applied. > - * > - * The estimation is based on the AWB statistics for the current frame. Red, > - * green and blue averages for all cells are first multiplied by the gain, and > - * then saturated to approximate the sensor behaviour at high brightness > - * values. The approximation is quite rough, as it doesn't take into account > - * non-linearities when approaching saturation. > - * > - * The relative luminance (Y) is computed from the linear RGB components using > - * the Rec. 601 formula. The values are normalized to the [0.0, 1.0] range, > - * where 1.0 corresponds to a theoretical perfect reflector of 100% reference > - * white. > - * > - * More detailed information can be found in: > - * https://en.wikipedia.org/wiki/Relative_luminance > - */ > -double Agc::estimateLuminance(IPAActiveState &activeState, > - const ipu3_uapi_grid_config &grid, > - const ipu3_uapi_stats_3a *stats, > - double gain) > -{ > - double redSum = 0, greenSum = 0, blueSum = 0; > - > - /* Sum the per-channel averages, saturated to 255. */ > - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { > - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { > - uint32_t cellPosition = cellY * stride_ + cellX; > - > - const ipu3_uapi_awb_set_item *cell = > - reinterpret_cast<const ipu3_uapi_awb_set_item *>( > - &stats->awb_raw_buffer.meta_data[cellPosition] > - ); > - const uint8_t G_avg = (cell->Gr_avg + cell->Gb_avg) / 2; > - > - redSum += std::min(cell->R_avg * gain, 255.0); > - greenSum += std::min(G_avg * gain, 255.0); > - blueSum += std::min(cell->B_avg * gain, 255.0); > - } > - } > - > - /* > - * Apply the AWB gains to approximate colours correctly, use the Rec. > - * 601 formula to calculate the relative luminance, and normalize it. > - */ > - double ySum = redSum * activeState.awb.gains.red * 0.299 > - + greenSum * activeState.awb.gains.green * 0.587 > - + blueSum * activeState.awb.gains.blue * 0.114; > - > - return ySum / (grid.height * grid.width) / 255; > -} > - > double Agc::estimateLuminance(double gain) > { > ASSERT(reds_.size() == greens_.size()); > @@ -422,42 +217,6 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame, > const ipu3_uapi_stats_3a *stats, > ControlList &metadata) > { > - /* > - * Estimate the gain needed to have the proportion of pixels in a given > - * desired range. iqMean is the mean value of the top 2% of the > - * cumulative histogram, and we want it to be as close as possible to a > - * configured target. > - */ > - double iqMean = measureBrightness(stats, context.configuration.grid.bdsGrid); > - double iqMeanGain = kEvGainTarget * knumHistogramBins / iqMean; > - > - /* > - * Estimate the gain needed to achieve a relative luminance target. To > - * account for non-linearity caused by saturation, the value needs to be > - * estimated in an iterative process, as multiplying by a gain will not > - * increase the relative luminance by the same factor if some image > - * regions are saturated. > - */ > - double yGain = 1.0; > - double yTarget = kRelativeLuminanceTarget; > - > - for (unsigned int i = 0; i < 8; i++) { > - double yValue = estimateLuminance(context.activeState, > - context.configuration.grid.bdsGrid, > - stats, yGain); > - double extraGain = std::min(10.0, yTarget / (yValue + .001)); > - > - yGain *= extraGain; > - LOG(IPU3Agc, Debug) << "Y value: " << yValue > - << ", Y target: " << yTarget > - << ", gives gain " << yGain; > - if (extraGain < 1.01) > - break; > - } > - > - computeExposure(context, frameContext, yGain, iqMeanGain); > - frameCount_++; > - > parseStatistics(stats, context.configuration.grid.bdsGrid); > > /* > diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h > index 8405da9d..78fa3c75 100644 > --- a/src/ipa/ipu3/algorithms/agc.h > +++ b/src/ipa/ipu3/algorithms/agc.h > @@ -38,29 +38,16 @@ public: > ControlList &metadata) override; > > private: > - double measureBrightness(const ipu3_uapi_stats_3a *stats, > - const ipu3_uapi_grid_config &grid) const; > - utils::Duration filterExposure(utils::Duration currentExposure); > - void computeExposure(IPAContext &context, IPAFrameContext &frameContext, > - double yGain, double iqMeanGain); > - double estimateLuminance(IPAActiveState &activeState, > - const ipu3_uapi_grid_config &grid, > - const ipu3_uapi_stats_3a *stats, > - double gain); > double estimateLuminance(double gain) override; > void parseStatistics(const ipu3_uapi_stats_3a *stats, > const ipu3_uapi_grid_config &grid); > > - uint64_t frameCount_; > - > utils::Duration minShutterSpeed_; > utils::Duration maxShutterSpeed_; > > double minAnalogueGain_; > double maxAnalogueGain_; > > - utils::Duration filteredExposure_; > - > uint32_t stride_; > IPAContext *context_; > std::vector<uint8_t> reds_; > -- > 2.34.1 >
Hi Dan, Thank you for the patch. On Fri, Mar 22, 2024 at 01:14:48PM +0000, Daniel Scally wrote: > Now that the IPU3's Agc is derived from MeanLuminanceAgc we can > delete all the unecessary bespoke functions. > > Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> > --- > src/ipa/ipu3/algorithms/agc.cpp | 241 -------------------------------- > src/ipa/ipu3/algorithms/agc.h | 13 -- > 2 files changed, 254 deletions(-) > > diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp > index a84534ea..08deff0c 100644 > --- a/src/ipa/ipu3/algorithms/agc.cpp > +++ b/src/ipa/ipu3/algorithms/agc.cpp > @@ -132,8 +132,6 @@ int Agc::configure(IPAContext &context, > activeState.agc.gain = minAnalogueGain_; > activeState.agc.exposure = 10ms / configuration.sensor.lineDuration; > > - frameCount_ = 0; > - > /* > * \todo We should use the first available mode rather than assume that > * the "Normal" modes are present in tuning data. > @@ -150,42 +148,6 @@ int Agc::configure(IPAContext &context, > return 0; > } > > -/** > - * \brief Estimate the mean value of the top 2% of the histogram > - * \param[in] stats The statistics computed by the ImgU > - * \param[in] grid The grid used to store the statistics in the IPU3 > - * \return The mean value of the top 2% of the histogram > - */ > -double Agc::measureBrightness(const ipu3_uapi_stats_3a *stats, > - const ipu3_uapi_grid_config &grid) const > -{ > - /* Initialise the histogram array */ > - uint32_t hist[knumHistogramBins] = { 0 }; > - > - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { > - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { > - uint32_t cellPosition = cellY * stride_ + cellX; > - > - const ipu3_uapi_awb_set_item *cell = > - reinterpret_cast<const ipu3_uapi_awb_set_item *>( > - &stats->awb_raw_buffer.meta_data[cellPosition] > - ); > - > - uint8_t gr = cell->Gr_avg; > - uint8_t gb = cell->Gb_avg; > - /* > - * Store the average green value to estimate the > - * brightness. Even the overexposed pixels are > - * taken into account. > - */ > - hist[(gr + gb) / 2]++; > - } > - } > - > - /* Estimate the quantile mean of the top 2% of the histogram. */ > - return Histogram(Span<uint32_t>(hist)).interQuantileMean(0.98, 1.0); > -} > - > void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, > const ipu3_uapi_grid_config &grid) > { > @@ -219,173 +181,6 @@ void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, > hist_ = Histogram(Span<uint32_t>(hist)); > } > > -/** > - * \brief Apply a filter on the exposure value to limit the speed of changes > - * \param[in] exposureValue The target exposure from the AGC algorithm > - * > - * The speed of the filter is adaptive, and will produce the target quicker > - * during startup, or when the target exposure is within 20% of the most recent > - * filter output. > - * > - * \return The filtered exposure > - */ > -utils::Duration Agc::filterExposure(utils::Duration exposureValue) > -{ > - double speed = 0.2; > - > - /* Adapt instantly if we are in startup phase. */ > - if (frameCount_ < kNumStartupFrames) > - speed = 1.0; > - > - /* > - * If we are close to the desired result, go faster to avoid making > - * multiple micro-adjustments. > - * \todo Make this customisable? > - */ > - if (filteredExposure_ < 1.2 * exposureValue && > - filteredExposure_ > 0.8 * exposureValue) > - speed = sqrt(speed); > - > - filteredExposure_ = speed * exposureValue + > - filteredExposure_ * (1.0 - speed); > - > - LOG(IPU3Agc, Debug) << "After filtering, exposure " << filteredExposure_; > - > - return filteredExposure_; > -} > - > -/** > - * \brief Estimate the new exposure and gain values > - * \param[inout] frameContext The shared IPA frame Context > - * \param[in] yGain The gain calculated based on the relative luminance target > - * \param[in] iqMeanGain The gain calculated based on the relative luminance target > - */ > -void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, > - double yGain, double iqMeanGain) > -{ > - const IPASessionConfiguration &configuration = context.configuration; > - /* Get the effective exposure and gain applied on the sensor. */ > - uint32_t exposure = frameContext.sensor.exposure; > - double analogueGain = frameContext.sensor.gain; > - > - /* Use the highest of the two gain estimates. */ > - double evGain = std::max(yGain, iqMeanGain); > - > - /* Consider within 1% of the target as correctly exposed */ > - if (utils::abs_diff(evGain, 1.0) < 0.01) > - LOG(IPU3Agc, Debug) << "We are well exposed (evGain = " > - << evGain << ")"; > - > - /* extracted from Rpi::Agc::computeTargetExposure */ > - > - /* Calculate the shutter time in seconds */ > - utils::Duration currentShutter = exposure * configuration.sensor.lineDuration; > - > - /* > - * Update the exposure value for the next computation using the values > - * of exposure and gain really used by the sensor. > - */ > - utils::Duration effectiveExposureValue = currentShutter * analogueGain; > - > - LOG(IPU3Agc, Debug) << "Actual total exposure " << currentShutter * analogueGain > - << " Shutter speed " << currentShutter > - << " Gain " << analogueGain > - << " Needed ev gain " << evGain; > - > - /* > - * Calculate the current exposure value for the scene as the latest > - * exposure value applied multiplied by the new estimated gain. > - */ > - utils::Duration exposureValue = effectiveExposureValue * evGain; > - > - /* Clamp the exposure value to the min and max authorized */ > - utils::Duration maxTotalExposure = maxShutterSpeed_ * maxAnalogueGain_; > - exposureValue = std::min(exposureValue, maxTotalExposure); > - LOG(IPU3Agc, Debug) << "Target total exposure " << exposureValue > - << ", maximum is " << maxTotalExposure; > - > - /* > - * Filter the exposure. > - * \todo estimate if we need to desaturate > - */ > - exposureValue = filterExposure(exposureValue); > - > - /* > - * Divide the exposure value as new exposure and gain values. > - * > - * Push the shutter time up to the maximum first, and only then > - * increase the gain. > - */ > - utils::Duration shutterTime = > - std::clamp<utils::Duration>(exposureValue / minAnalogueGain_, > - minShutterSpeed_, maxShutterSpeed_); > - double stepGain = std::clamp(exposureValue / shutterTime, > - minAnalogueGain_, maxAnalogueGain_); > - LOG(IPU3Agc, Debug) << "Divided up shutter and gain are " > - << shutterTime << " and " > - << stepGain; > -} > - > -/** > - * \brief Estimate the relative luminance of the frame with a given gain > - * \param[in] frameContext The shared IPA frame context > - * \param[in] grid The grid used to store the statistics in the IPU3 > - * \param[in] stats The IPU3 statistics and ISP results > - * \param[in] gain The gain to apply to the frame > - * \return The relative luminance > - * > - * This function estimates the average relative luminance of the frame that > - * would be output by the sensor if an additional \a gain was applied. > - * > - * The estimation is based on the AWB statistics for the current frame. Red, > - * green and blue averages for all cells are first multiplied by the gain, and > - * then saturated to approximate the sensor behaviour at high brightness > - * values. The approximation is quite rough, as it doesn't take into account > - * non-linearities when approaching saturation. > - * > - * The relative luminance (Y) is computed from the linear RGB components using > - * the Rec. 601 formula. The values are normalized to the [0.0, 1.0] range, > - * where 1.0 corresponds to a theoretical perfect reflector of 100% reference > - * white. > - * > - * More detailed information can be found in: > - * https://en.wikipedia.org/wiki/Relative_luminance All this documentation is list. The first paragraph can be moved to the documentation in the base class, the rest can go to ipa::ipu3::algorithms::Agc::estimateLuminance(const double gain). The base class should also explain why luminance estimation is needed (due to saturation), and possibly how derived classes can implement that depending on what statistics they have. > - */ > -double Agc::estimateLuminance(IPAActiveState &activeState, > - const ipu3_uapi_grid_config &grid, > - const ipu3_uapi_stats_3a *stats, > - double gain) > -{ > - double redSum = 0, greenSum = 0, blueSum = 0; > - > - /* Sum the per-channel averages, saturated to 255. */ > - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { > - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { > - uint32_t cellPosition = cellY * stride_ + cellX; > - > - const ipu3_uapi_awb_set_item *cell = > - reinterpret_cast<const ipu3_uapi_awb_set_item *>( > - &stats->awb_raw_buffer.meta_data[cellPosition] > - ); > - const uint8_t G_avg = (cell->Gr_avg + cell->Gb_avg) / 2; > - > - redSum += std::min(cell->R_avg * gain, 255.0); > - greenSum += std::min(G_avg * gain, 255.0); > - blueSum += std::min(cell->B_avg * gain, 255.0); > - } > - } > - > - /* > - * Apply the AWB gains to approximate colours correctly, use the Rec. > - * 601 formula to calculate the relative luminance, and normalize it. > - */ > - double ySum = redSum * activeState.awb.gains.red * 0.299 > - + greenSum * activeState.awb.gains.green * 0.587 > - + blueSum * activeState.awb.gains.blue * 0.114; > - > - return ySum / (grid.height * grid.width) / 255; > -} > - > double Agc::estimateLuminance(double gain) > { > ASSERT(reds_.size() == greens_.size()); > @@ -422,42 +217,6 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame, > const ipu3_uapi_stats_3a *stats, > ControlList &metadata) > { > - /* > - * Estimate the gain needed to have the proportion of pixels in a given > - * desired range. iqMean is the mean value of the top 2% of the > - * cumulative histogram, and we want it to be as close as possible to a > - * configured target. > - */ > - double iqMean = measureBrightness(stats, context.configuration.grid.bdsGrid); > - double iqMeanGain = kEvGainTarget * knumHistogramBins / iqMean; > - > - /* > - * Estimate the gain needed to achieve a relative luminance target. To > - * account for non-linearity caused by saturation, the value needs to be > - * estimated in an iterative process, as multiplying by a gain will not > - * increase the relative luminance by the same factor if some image > - * regions are saturated. > - */ > - double yGain = 1.0; > - double yTarget = kRelativeLuminanceTarget; > - > - for (unsigned int i = 0; i < 8; i++) { > - double yValue = estimateLuminance(context.activeState, > - context.configuration.grid.bdsGrid, > - stats, yGain); > - double extraGain = std::min(10.0, yTarget / (yValue + .001)); > - > - yGain *= extraGain; > - LOG(IPU3Agc, Debug) << "Y value: " << yValue > - << ", Y target: " << yTarget > - << ", gives gain " << yGain; > - if (extraGain < 1.01) > - break; > - } > - > - computeExposure(context, frameContext, yGain, iqMeanGain); > - frameCount_++; > - > parseStatistics(stats, context.configuration.grid.bdsGrid); > > /* > diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h > index 8405da9d..78fa3c75 100644 > --- a/src/ipa/ipu3/algorithms/agc.h > +++ b/src/ipa/ipu3/algorithms/agc.h > @@ -38,29 +38,16 @@ public: > ControlList &metadata) override; > > private: > - double measureBrightness(const ipu3_uapi_stats_3a *stats, > - const ipu3_uapi_grid_config &grid) const; > - utils::Duration filterExposure(utils::Duration currentExposure); > - void computeExposure(IPAContext &context, IPAFrameContext &frameContext, > - double yGain, double iqMeanGain); > - double estimateLuminance(IPAActiveState &activeState, > - const ipu3_uapi_grid_config &grid, > - const ipu3_uapi_stats_3a *stats, > - double gain); > double estimateLuminance(double gain) override; > void parseStatistics(const ipu3_uapi_stats_3a *stats, > const ipu3_uapi_grid_config &grid); > > - uint64_t frameCount_; > - > utils::Duration minShutterSpeed_; > utils::Duration maxShutterSpeed_; > > double minAnalogueGain_; > double maxAnalogueGain_; > > - utils::Duration filteredExposure_; > - > uint32_t stride_; > IPAContext *context_; > std::vector<uint8_t> reds_;
diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp index a84534ea..08deff0c 100644 --- a/src/ipa/ipu3/algorithms/agc.cpp +++ b/src/ipa/ipu3/algorithms/agc.cpp @@ -132,8 +132,6 @@ int Agc::configure(IPAContext &context, activeState.agc.gain = minAnalogueGain_; activeState.agc.exposure = 10ms / configuration.sensor.lineDuration; - frameCount_ = 0; - /* * \todo We should use the first available mode rather than assume that * the "Normal" modes are present in tuning data. @@ -150,42 +148,6 @@ int Agc::configure(IPAContext &context, return 0; } -/** - * \brief Estimate the mean value of the top 2% of the histogram - * \param[in] stats The statistics computed by the ImgU - * \param[in] grid The grid used to store the statistics in the IPU3 - * \return The mean value of the top 2% of the histogram - */ -double Agc::measureBrightness(const ipu3_uapi_stats_3a *stats, - const ipu3_uapi_grid_config &grid) const -{ - /* Initialise the histogram array */ - uint32_t hist[knumHistogramBins] = { 0 }; - - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { - uint32_t cellPosition = cellY * stride_ + cellX; - - const ipu3_uapi_awb_set_item *cell = - reinterpret_cast<const ipu3_uapi_awb_set_item *>( - &stats->awb_raw_buffer.meta_data[cellPosition] - ); - - uint8_t gr = cell->Gr_avg; - uint8_t gb = cell->Gb_avg; - /* - * Store the average green value to estimate the - * brightness. Even the overexposed pixels are - * taken into account. - */ - hist[(gr + gb) / 2]++; - } - } - - /* Estimate the quantile mean of the top 2% of the histogram. */ - return Histogram(Span<uint32_t>(hist)).interQuantileMean(0.98, 1.0); -} - void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, const ipu3_uapi_grid_config &grid) { @@ -219,173 +181,6 @@ void Agc::parseStatistics(const ipu3_uapi_stats_3a *stats, hist_ = Histogram(Span<uint32_t>(hist)); } -/** - * \brief Apply a filter on the exposure value to limit the speed of changes - * \param[in] exposureValue The target exposure from the AGC algorithm - * - * The speed of the filter is adaptive, and will produce the target quicker - * during startup, or when the target exposure is within 20% of the most recent - * filter output. - * - * \return The filtered exposure - */ -utils::Duration Agc::filterExposure(utils::Duration exposureValue) -{ - double speed = 0.2; - - /* Adapt instantly if we are in startup phase. */ - if (frameCount_ < kNumStartupFrames) - speed = 1.0; - - /* - * If we are close to the desired result, go faster to avoid making - * multiple micro-adjustments. - * \todo Make this customisable? - */ - if (filteredExposure_ < 1.2 * exposureValue && - filteredExposure_ > 0.8 * exposureValue) - speed = sqrt(speed); - - filteredExposure_ = speed * exposureValue + - filteredExposure_ * (1.0 - speed); - - LOG(IPU3Agc, Debug) << "After filtering, exposure " << filteredExposure_; - - return filteredExposure_; -} - -/** - * \brief Estimate the new exposure and gain values - * \param[inout] frameContext The shared IPA frame Context - * \param[in] yGain The gain calculated based on the relative luminance target - * \param[in] iqMeanGain The gain calculated based on the relative luminance target - */ -void Agc::computeExposure(IPAContext &context, IPAFrameContext &frameContext, - double yGain, double iqMeanGain) -{ - const IPASessionConfiguration &configuration = context.configuration; - /* Get the effective exposure and gain applied on the sensor. */ - uint32_t exposure = frameContext.sensor.exposure; - double analogueGain = frameContext.sensor.gain; - - /* Use the highest of the two gain estimates. */ - double evGain = std::max(yGain, iqMeanGain); - - /* Consider within 1% of the target as correctly exposed */ - if (utils::abs_diff(evGain, 1.0) < 0.01) - LOG(IPU3Agc, Debug) << "We are well exposed (evGain = " - << evGain << ")"; - - /* extracted from Rpi::Agc::computeTargetExposure */ - - /* Calculate the shutter time in seconds */ - utils::Duration currentShutter = exposure * configuration.sensor.lineDuration; - - /* - * Update the exposure value for the next computation using the values - * of exposure and gain really used by the sensor. - */ - utils::Duration effectiveExposureValue = currentShutter * analogueGain; - - LOG(IPU3Agc, Debug) << "Actual total exposure " << currentShutter * analogueGain - << " Shutter speed " << currentShutter - << " Gain " << analogueGain - << " Needed ev gain " << evGain; - - /* - * Calculate the current exposure value for the scene as the latest - * exposure value applied multiplied by the new estimated gain. - */ - utils::Duration exposureValue = effectiveExposureValue * evGain; - - /* Clamp the exposure value to the min and max authorized */ - utils::Duration maxTotalExposure = maxShutterSpeed_ * maxAnalogueGain_; - exposureValue = std::min(exposureValue, maxTotalExposure); - LOG(IPU3Agc, Debug) << "Target total exposure " << exposureValue - << ", maximum is " << maxTotalExposure; - - /* - * Filter the exposure. - * \todo estimate if we need to desaturate - */ - exposureValue = filterExposure(exposureValue); - - /* - * Divide the exposure value as new exposure and gain values. - * - * Push the shutter time up to the maximum first, and only then - * increase the gain. - */ - utils::Duration shutterTime = - std::clamp<utils::Duration>(exposureValue / minAnalogueGain_, - minShutterSpeed_, maxShutterSpeed_); - double stepGain = std::clamp(exposureValue / shutterTime, - minAnalogueGain_, maxAnalogueGain_); - LOG(IPU3Agc, Debug) << "Divided up shutter and gain are " - << shutterTime << " and " - << stepGain; -} - -/** - * \brief Estimate the relative luminance of the frame with a given gain - * \param[in] frameContext The shared IPA frame context - * \param[in] grid The grid used to store the statistics in the IPU3 - * \param[in] stats The IPU3 statistics and ISP results - * \param[in] gain The gain to apply to the frame - * \return The relative luminance - * - * This function estimates the average relative luminance of the frame that - * would be output by the sensor if an additional \a gain was applied. - * - * The estimation is based on the AWB statistics for the current frame. Red, - * green and blue averages for all cells are first multiplied by the gain, and - * then saturated to approximate the sensor behaviour at high brightness - * values. The approximation is quite rough, as it doesn't take into account - * non-linearities when approaching saturation. - * - * The relative luminance (Y) is computed from the linear RGB components using - * the Rec. 601 formula. The values are normalized to the [0.0, 1.0] range, - * where 1.0 corresponds to a theoretical perfect reflector of 100% reference - * white. - * - * More detailed information can be found in: - * https://en.wikipedia.org/wiki/Relative_luminance - */ -double Agc::estimateLuminance(IPAActiveState &activeState, - const ipu3_uapi_grid_config &grid, - const ipu3_uapi_stats_3a *stats, - double gain) -{ - double redSum = 0, greenSum = 0, blueSum = 0; - - /* Sum the per-channel averages, saturated to 255. */ - for (unsigned int cellY = 0; cellY < grid.height; cellY++) { - for (unsigned int cellX = 0; cellX < grid.width; cellX++) { - uint32_t cellPosition = cellY * stride_ + cellX; - - const ipu3_uapi_awb_set_item *cell = - reinterpret_cast<const ipu3_uapi_awb_set_item *>( - &stats->awb_raw_buffer.meta_data[cellPosition] - ); - const uint8_t G_avg = (cell->Gr_avg + cell->Gb_avg) / 2; - - redSum += std::min(cell->R_avg * gain, 255.0); - greenSum += std::min(G_avg * gain, 255.0); - blueSum += std::min(cell->B_avg * gain, 255.0); - } - } - - /* - * Apply the AWB gains to approximate colours correctly, use the Rec. - * 601 formula to calculate the relative luminance, and normalize it. - */ - double ySum = redSum * activeState.awb.gains.red * 0.299 - + greenSum * activeState.awb.gains.green * 0.587 - + blueSum * activeState.awb.gains.blue * 0.114; - - return ySum / (grid.height * grid.width) / 255; -} - double Agc::estimateLuminance(double gain) { ASSERT(reds_.size() == greens_.size()); @@ -422,42 +217,6 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame, const ipu3_uapi_stats_3a *stats, ControlList &metadata) { - /* - * Estimate the gain needed to have the proportion of pixels in a given - * desired range. iqMean is the mean value of the top 2% of the - * cumulative histogram, and we want it to be as close as possible to a - * configured target. - */ - double iqMean = measureBrightness(stats, context.configuration.grid.bdsGrid); - double iqMeanGain = kEvGainTarget * knumHistogramBins / iqMean; - - /* - * Estimate the gain needed to achieve a relative luminance target. To - * account for non-linearity caused by saturation, the value needs to be - * estimated in an iterative process, as multiplying by a gain will not - * increase the relative luminance by the same factor if some image - * regions are saturated. - */ - double yGain = 1.0; - double yTarget = kRelativeLuminanceTarget; - - for (unsigned int i = 0; i < 8; i++) { - double yValue = estimateLuminance(context.activeState, - context.configuration.grid.bdsGrid, - stats, yGain); - double extraGain = std::min(10.0, yTarget / (yValue + .001)); - - yGain *= extraGain; - LOG(IPU3Agc, Debug) << "Y value: " << yValue - << ", Y target: " << yTarget - << ", gives gain " << yGain; - if (extraGain < 1.01) - break; - } - - computeExposure(context, frameContext, yGain, iqMeanGain); - frameCount_++; - parseStatistics(stats, context.configuration.grid.bdsGrid); /* diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h index 8405da9d..78fa3c75 100644 --- a/src/ipa/ipu3/algorithms/agc.h +++ b/src/ipa/ipu3/algorithms/agc.h @@ -38,29 +38,16 @@ public: ControlList &metadata) override; private: - double measureBrightness(const ipu3_uapi_stats_3a *stats, - const ipu3_uapi_grid_config &grid) const; - utils::Duration filterExposure(utils::Duration currentExposure); - void computeExposure(IPAContext &context, IPAFrameContext &frameContext, - double yGain, double iqMeanGain); - double estimateLuminance(IPAActiveState &activeState, - const ipu3_uapi_grid_config &grid, - const ipu3_uapi_stats_3a *stats, - double gain); double estimateLuminance(double gain) override; void parseStatistics(const ipu3_uapi_stats_3a *stats, const ipu3_uapi_grid_config &grid); - uint64_t frameCount_; - utils::Duration minShutterSpeed_; utils::Duration maxShutterSpeed_; double minAnalogueGain_; double maxAnalogueGain_; - utils::Duration filteredExposure_; - uint32_t stride_; IPAContext *context_; std::vector<uint8_t> reds_;
Now that the IPU3's Agc is derived from MeanLuminanceAgc we can delete all the unecessary bespoke functions. Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> --- src/ipa/ipu3/algorithms/agc.cpp | 241 -------------------------------- src/ipa/ipu3/algorithms/agc.h | 13 -- 2 files changed, 254 deletions(-)