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2021-11-24ipa: ipu3: Convert to pragma onceKieran Bingham
Remove the verbose #ifndef/#define/#endif pattern for maintaining header idempotency, and replace it with a simple #pragma once. This simplifies the headers, and prevents redundant changes when header files get moved. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
2021-11-23ipa: ipu3: agc: Saturate the averages when computing relative luminanceLaurent Pinchart
The relative luminance is calculated using an iterative process to account for saturation in the sensor, as multiplying pixels by a gain doesn't increase the relative luminance by the same factor if some regions are saturated. Relative luminance estimation doesn't apply a saturation, which produces a value that doesn't match what the sensor will output, and defeats the point of the iterative process. Fix it. Fixes: f8f07f9468c6 ("ipa: ipu3: agc: Improve gain calculation") Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-23ipa: ipu3: agc: Return the inter-quantile mean from measureBrightness()Laurent Pinchart
The inter-quantile mean is a value that is computed as part of the AGC run. It doesn't need to be stored in a member variable. Return it from measureBrightness(), which makes the flow of data easier to follow. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-23ipa: ipu3: agc: Rename currentYGainLaurent Pinchart
The "current" prefix in the currentYGain variable name is confusing: - In Agc::estimateLuminance(), the variable contains the gain to be applied to the image, which is neither a "current" gain nor a "Y" gain. Rename it to "gain". - In Agc::computeExposure(), the variable contains the gain computed by the relative luminance method, so rename it to "yGain". While at it, rename variables to match the libcamera coding style. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-23ipa: ipu3: agc: Standardize vocabulary on "relative luminance"Laurent Pinchart
The AGC computes the average relative luminance of the frame and calls the value "normalized luma", "brightness" or "initialY". The latter is the most accurate term, as the relative luminance is abbreviated Y, but the "initial" prefix isn't accurate. Standardize the vocabulary on "relative luminance" in code and comments, abbreviating it to Y when needed. While at it, rename variables to match the libcamera coding style. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-23ipa: ipu3: agc: Drop kMaxLuminance constantLaurent Pinchart
The kMaxLuminance constant is badly named, it's not a maximum luminance, but the maximum integer value output by the AWB statistics engine for per-channel averages. The constant is used in a single place, hardcoding the value is actually more readable. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-16ipa: ipu3: agc: Remove the threshold for the histogram calculationJean-Michel Hautbois
Until commit f8f07f9468c6 (ipa: ipu3: agc: Improve gain calculation) the gain to apply on the exposure value was only using the histogram. Now that the global brightness of the frame is estimated too, we don't need to remove part of the saturated pixels from the equation anymore. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-11-15ipa: ipu3: awb: Add support for color temperatureJean-Michel Hautbois
The AWB estimates the color temperature, but it is not used at all. It can be useful for debug purpose at least, but also for lux estimation later, to be able to know the temperature estimated for a given frame. Add a new member to the IPAFrameContext::awb for this purpose, and update the value in AWB. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Store exposure in units of timeJean-Michel Hautbois
The minimum and maximum exposure are stored in lines. Replace it by values in time to simplify the calculations. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Update previous exposure valueJean-Michel Hautbois
Previously, the exposure value was calculated based on the estimated shutter time and gain applied. Now that we have the real values for the current frame, use those before estimating the next one and rename the variable accordingly. As the exposure value is updated in the beginning of the computation, there is no need to initialize effectiveExposureValue anymore in the configure call, and it can be a local variable and not a class variable anymore. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Improve gain calculationJean-Michel Hautbois
When an image is partially saturated, its brightness is not increasing linearly when the shutter time or gain increases. It is a big issue with a backlight as the algorithm is fading to darkness right now. Introduce a function to estimate the brightness of the frame, based on the current exposure/gain and loop on it several times to estimate it again and approach the non linear function. Inspired-by: 7de5506c30b3 ("libcamera: src: ipa: raspberrypi: agc: Improve gain update calculation for partly saturated images") Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Refactor ev gain calculation and testingJean-Michel Hautbois
When we compute the new gain, we use the iqMean_ and estimate an exposure value gain to apply. Return early when the gain is less than 1%. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Compute the gain for each frameJean-Michel Hautbois
Now that we have the real exposure applied at each frame, remove the early return based on a frame counter and compute the gain for each frame. Introduce a number of startup frames during which the filter speed is 1.0, meaning we apply instantly the exposure value calculated and not a slower filtered one. This is used to have a faster convergence, and those frames may be dropped in a future development to hide the convergance process from the viewer. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: agc: Limit the number of saturated cellsJean-Michel Hautbois
When the histogram is calculated, we check if a cell is saturated or not before cumulating its green value. This is wrong, and it can lead to an empty histogram in case of a fully saturated frame. Use a constant to limit the amount of pixels within a cell before considering it saturated. If at the end of the loop we still have an empty histogram, then make it a fully saturated one. Bug: https://bugs.libcamera.org/show_bug.cgi?id=84 Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-11-15ipa: ipu3: Use sensor controls to update frameContextJean-Michel Hautbois
The pipeline handler populates the new sensorControls ControlList, to have the effective exposure and gain values for the current frame. This is done when a statistics buffer is received. Make those values the frameContext::sensor values for the frame when the EventStatReady event is received. AGC also needs to use frameContext.sensor as its input values and frameContext.agc as its output values. Modify computeExposure by passing it the frameContext instead of individual exposure and gain values. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-10-26ipa: ipu3: agc: Clamp shutter speedJean-Michel Hautbois
In case the maximum exposure received from the sensor is very high, we can have a very high shutter speed with a small analogue gain, and it may result in very slow framerate. We are not really supporting it for the moment, so clamp the shutter speed to an arbitrary value of 60ms. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Tested-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: algorithms: awb: Privatize internal structuresKieran Bingham
The struct RGB and struct AwbStatus are used only by the internal implementation of the AWB algorithm module. Move them into the private class declaration. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
2021-10-26ipa: ipu3: Fix the IPU3 AWB doxygen referencesKieran Bingham
The AWB AwbStatus structure is contained within the Awb class. Fix the Doxygen reference so that it can be found. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
2021-10-26ipa: ipu3: tonemapping: Add the documentation for ToneMappingJean-Michel Hautbois
The tone mapping algorithm is currently undocumented. Provide an introduction and overview to the implementation as the class definition and document how the algorithm operates in the process and prepare methods. 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: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: tonemapping: Implement configure callJean-Michel Hautbois
Let the algorithm perform its initial configuration. Implement configure() to set a default gamma value and let process do the updates needed. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: tonemapping: Generate the LUT only on gamma changeJean-Michel Hautbois
The tone mapping algorithm calculates the gamma curve for every frame, regardless of whether the gamma value has changed or not. This issue is exasperated as we currently hardcode the gamma to a single value. Optimise the implementation to only recalculate the look up table when the gamma setting is changed, and store the gamma setting of the LUT curve as part of the IPA context. 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: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: agc: Document AGC mean-based algorithmJean-Michel Hautbois
The AGC class was not documented while developing. Extend that to reference the origins of the implementation, and improve the descriptions on how the algorithm operates internally. While at it, rename the functions which have bad names. 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: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: awb: Reword accumulator documentationJean-Michel Hautbois
Now that we moved the diagram into the AWB class documentation, reword the accumulator documentation to make it clear it is not meant to be used only in AWB. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-26ipa: ipu3: awb: Add AWB class documentationJean-Michel Hautbois
The AWB algorithm is based on the Grey world algorithm and uses the statistics generated by the ImgU for that. Explain how it uses those, and reference the original algorithm at the same time. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: Use sensor limits for analogue gainJean-Michel Hautbois
Instead of using constants for the analogue gains limits, use the minimum and maximum from the configured sensor. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Remove unused variablesJean-Michel Hautbois
We currently control the exposure value by the shutter speed and the analogue gain. We can't use the digital gain to have more than the maximum exposure value calculated because we are not controlling it. Remove unused code associated with this digital gain. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Refactor condition on exposure correctionJean-Michel Hautbois
Simplify the reading by removing one level of indentation to return early when the change is small between two calls. Reword the LOG() message when we are correctly exposed, and move the lastFrame_ variable to update it even if the change is small. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Introduce previous exposure valueJean-Michel Hautbois
We need to calculate the gain on the previous exposure value calculated. Now that we initialise the exposure and gain values in configure(), we know the initial exposure value, and we can set it before any loop is running. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Rename gains properlyJean-Michel Hautbois
We have mixed terms between gain, analogue gain and the exposure value gain. Make it clear when we are using the analogue gain from the sensor, and when we are using the calculated gain to be applied to the exposure value to reach the target. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Simplify division of exposure/gainJean-Michel Hautbois
Until now, the algorithm makes complex assumptions when dividing the exposure and analogue gain values. Instead, use a simpler clamping of the shutter speed first, and then of the analogue gain, based on the limits configured. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Use filtered exposure valuesJean-Michel Hautbois
We are filtering the exposure value to limit the gain to apply, but we are not using the result. Fix it. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Change analogue gain limitsJean-Michel Hautbois
The gains are currently set as a uint32_t while the analogue gain is passed as a double. We also have a default maximum analogue gain of 15 which is quite high for a number of sensors. Use a maximum value of 8 which should really be configured by the IPA and not fixed as it is now. While at it make it a double. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Change exposure limitsJean-Michel Hautbois
We are using arbitrary constants for the exposure limit in a number of lines. Instead of using static constants for those, use the limits of the sensor passed in IPASessionConfiguration and cache those. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: agc: Rename exposure values properlyJean-Michel Hautbois
The exposure value is filtered in filterExposure() using the currentExposure_ and setting a prevExposure_ variable. This is misnamed as it is not the previous exposure, but a filtered value. Rename it accordingly. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: awb: Change minimal green threshold valueJean-Michel Hautbois
When zones are used for the grey world algorithm, they are only considered if their average green value is at least 32/255 to exclude zones that are too dark and don't provide relevant colour information (on the opposite side of the spectrum, saturated regions are excluded by the ImgU statistics engine). The algorithm requires a minimal number of zones that meet this criteria in order to run. Now that we correct the black level, the 32/255 minimal value is a bit high and prevents the algorithm for running in low-light conditions. Lower the value to 16/255 to fix it. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: awb: Use saturation under 90%Jean-Michel Hautbois
The AWB grey world algorithm tries to find a grey value and it can't do it on over-exposed images. To exclude those, the saturation ratio is used for each cell, and the cell is included only if this ratio is 0. Now that we have changed the threshold, more cells may be considered as partially saturated and excluded, preventing the algorithm from running efficiently. Change that behaviour, and consider 90% as a good enough ratio. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-22ipa: ipu3: set frameContext before controlsJean-Michel Hautbois
The AGC frame context needs to be initialised correctly for the first iteration. Until now, the IPA uses the minimum exposure and gain values and caches those in local variables. In order to give the sensor limits to AGC, create a new structure in IPASessionConfiguration. Store the exposure in time (and not line duration) and the analogue gain after CameraSensorHelper conversion. Set the gain and exposure appropriately to the current values known to the IPA and remove the setting of exposure and gain in IPAIPU3 as those are now fully controlled by IPU3Agc. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-22ipa: ipu3: awb: Set a threshold for the green saturationJean-Michel Hautbois
We can have a saturation ratio per cell, giving the percentage of pixels over a threshold within a cell where 100% is set to 0xff. The parameter structure 'ipu3_uapi_awb_config_s' contains four fields to set the threshold, one per channel. The blue field is also used to configure the ImgU and make it calculate the saturation ratio or not. Set a green value saturated when it is more than 230 (90% of the maximum value 255, coded as 8191). As this is the only channel used for AGC, there is no need to apply it to the other ones. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2021-10-19ipa: ipu3: agc: Remove "using" directive from agc.h headerLaurent Pinchart
"using" directives are harmful in headers, as they propagate the namespace short-circuit to all files that include the header, directly or indirectly. Drop the directive from agc.h, and use utils::Duration explicitly. While at it, shorten the namespace qualifier from libcamera::utils:: to utils:: in agc.cpp for Duration. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-10-19ipa: ipu3: awb: Don't pass member variable to member functionLaurent Pinchart
The Awb::generateZones() member function fills the zones vector passed as an argument, which is actually a member variable. Use it directly in the function. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
2021-10-06ipa: ipu3: Replace ipa::ipu3::algorithms::Ipu3AwbCellJean-Michel Hautbois
The intel-ipu3.h public interface from the kernel does not define how to parse the statistics for a cell. This had to be identified by a process of reverse engineering, and later identifying the structures from [0] leading to our custom definition of struct Ipu3AwbCell. [0] https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/refs/heads/master/hal/intel/include/ia_imaging/awb_public.h To improve the kernel interface, a proposal has been made to the linux-kernel [1] to incorporate the memory layout for each cell into the intel-ipu3 header directly. [1] https://lore.kernel.org/linux-media/20211005202019.253353-1-jeanmichel.hautbois@ideasonboard.com/ Update our local copy of the intel-ipu3.h to match the proposal and change the AGC and AWB algorithms to reference that structure directly, allowing us to remove the deprecated custom Ipu3AwbCell definition. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: agc: Rewrite and simplify the brightness loopJean-Michel Hautbois
Now that we know how the AWB statistics are formatted, use a simplified loop in processBrightness() to parse the green values and get the histogram. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: awb: Introduce Black Level CorrectionJean-Michel Hautbois
The pixels output by the camera normally include a black level, because sensors do not always report a signal level of '0' for black. Pixels at or below this level should be considered black and to achieve that, we need to substract an offset to all the pixels. This can be taken into account by reading the lowest value of a special region on sensors which is not exposed to light. This provides a substracting factor to be able to adjust the expected black levels in the resulting images. For a camera outputting 10-bit pixel values (in the range 0 to 1023) a typical black level might be 64. It is a fixed value, obtained by capturing a raw frame with minimum exposure and gain fixed to 1.0 while covering the sensor (the darker the better). We consider it good enough as a very first approximation, until we measure it during a tuning process and include it in a configuration file Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: awb: Use the line stride for the statsJean-Michel Hautbois
The statistics buffer 'ipu3_uapi_awb_raw_buffer' stores the ImgU calculation results in a buffer aligned horizontally to a multiple of 4 cells. The AWB loop should take care of it to add the proper offset between lines and avoid any staircase effect. It is no longer required to pass the grid configuration context to the private functions called from process() which simplifies the code flow. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: awb: Correct the gain multipliersJean-Michel Hautbois
The gains have a precision u3.13, range [0, 8[ which means that a gain multiplier value of 1.0 is represented as a multiplication by 8192 in the ImgU. Correct the gains as this was misunderstood in the first place. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: awb: Correct the relevant zones proportionJean-Michel Hautbois
The algorithm uses the statistics of a cell only if there is not too much saturated pixels in it. The grey world algorithm works fine when there are a limited number of outliers. Consider a valid zone to be at least 80% of unsaturated cells in it. This value could very well be configurable, and make the algorithm more or less tolerant. While at it, implement it in a configure() call as it will not change during execution, and cache the cellsPerZone values estimated with std::round as we are using cmath. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: awb: Make the naming consistentJean-Michel Hautbois
The variables mix the terms cell, region and zone. It can confuse the reader, and make the algorithm more difficult to follow. Rename the local variables to be consistent with their definitions: - Cells are defined in Pixels - Zones are defined in Cells There is no "region" as such, so replace it with the correct term. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: Change Accumulator structure layoutJean-Michel Hautbois
The pixel component sums for the Accumulator are inconsistent with other similar structures such as the IPAFrameContext::awb::gains. Group the red, green, and blue sums together in a struct and store them as uint64_t to reduce potential architectural differences. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: Rename IspStatsRegion to AccumulatorJean-Michel Hautbois
The IspStatsRegion structure was introduced as an attempt to prepare for a generic AWB algorithm structure. The structure name by itself is not explicit and it is too optimistic to try and make a generic one for now. Its role is to accumulate the pixels in a given zone. Rename it to accumulator, and remove the uncounted field at the same time. It is always possible to know how many pixels are not relevant for the algorithm by calculating total-counted. The uncounted field was only declared and not used. Amend the documentation accordingly. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2021-10-06ipa: ipu3: Move the AWB stats structuresJean-Michel Hautbois
The structure Ipu3AwbCell describes the AWB stats layout on the kernel side. We will need it to be used by the AGC algorithm to be introduced later, so let's make it visible from ipa::ipu3::algorithms and not only for the AWB class. The IspStatsRegion will be needed by AGC too, so let's move it in the same namespace too. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>