[libcamera-devel] [PATCH] ipa: rpi: Add "focus" algorithm

[Laurent Pinchart]

Hi David,

Thank you for the patch.

On Thu, May 28, 2020 at 03:51:32PM +0100, Naushir Patuck wrote:
> From: David Plowman <david.plowman at raspberrypi.com>
> 
> Adds FocusStatus to the image metadata, containing contrast measurements
> across the image. Optionally also prints a contrast measure to the
> console, to aid in manual adjustment of the lens. Note that it is not an
> actual auto-focus algorithm that can drive a lens!

An interesting exercise for a motivated reader :-)

> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> ---
>  src/ipa/raspberrypi/controller/focus_status.h | 26 ++++++++++
>  src/ipa/raspberrypi/controller/rpi/focus.cpp  | 51 +++++++++++++++++++
>  src/ipa/raspberrypi/controller/rpi/focus.hpp  | 31 +++++++++++
>  src/ipa/raspberrypi/data/imx477.json          |  4 ++
>  src/ipa/raspberrypi/meson.build               |  1 +
>  5 files changed, 113 insertions(+)
>  create mode 100644 src/ipa/raspberrypi/controller/focus_status.h
>  create mode 100644 src/ipa/raspberrypi/controller/rpi/focus.cpp
>  create mode 100644 src/ipa/raspberrypi/controller/rpi/focus.hpp
> 
> diff --git a/src/ipa/raspberrypi/controller/focus_status.h b/src/ipa/raspberrypi/controller/focus_status.h
> new file mode 100644
> index 00000000..3ad88777
> --- /dev/null
> +++ b/src/ipa/raspberrypi/controller/focus_status.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> + *
> + * focus_status.h - focus measurement status
> + */
> +#pragma once
> +
> +#include <linux/bcm2835-isp.h>
> +
> +// The focus algorithm should post the following structure into the image's
> +// "focus.status" metadata. Recall that it's only reporting focus (contrast)
> +// measurements, it's not driving any kind of auto-focus algorithm!
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +struct FocusStatus {
> +	int num;
> +	uint32_t focus_measures[FOCUS_REGIONS];
> +};
> +
> +#ifdef __cplusplus
> +}
> +#endif
> diff --git a/src/ipa/raspberrypi/controller/rpi/focus.cpp b/src/ipa/raspberrypi/controller/rpi/focus.cpp
> new file mode 100644
> index 00000000..d6cdc4bf
> --- /dev/null
> +++ b/src/ipa/raspberrypi/controller/rpi/focus.cpp
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> + *
> + * focus.cpp - focus algorithm
> + */
> +#include <stdint.h>
> +
> +#include "../focus_status.h"
> +#include "../logging.hpp"
> +#include "focus.hpp"
> +
> +using namespace RPi;
> +
> +#define NAME "rpi.focus"
> +
> +Focus::Focus(Controller *controller)
> +	: Algorithm(controller)
> +{
> +}
> +
> +char const *Focus::Name() const
> +{
> +	return NAME;
> +}
> +
> +void Focus::Read(boost::property_tree::ptree const &params)
> +{
> +	print_ = params.get<int>("print", 0);
> +}
> +
> +void Focus::Process(StatisticsPtr &stats, Metadata *image_metadata)
> +{
> +	FocusStatus status;
> +	int i;

As i is never negative, should it be an unsigned int ?

Apart from this,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Let me know if you're fine with the change, in which case I'll modify
the patch when applying.

> +	for (i = 0; i < FOCUS_REGIONS; i++)
> +		status.focus_measures[i] = stats->focus_stats[i].contrast_val[1][1] / 1000;
> +	status.num = i;
> +	image_metadata->Set("focus.status", status);
> +	if (print_) {
> +		uint32_t value = (status.focus_measures[5] + status.focus_measures[6]) / 10;
> +		RPI_LOG("Focus contrast measure: " << value);
> +	}
> +}
> +
> +/* Register algorithm with the system. */
> +static Algorithm *Create(Controller *controller)
> +{
> +	return new Focus(controller);
> +}
> +static RegisterAlgorithm reg(NAME, &Create);
> diff --git a/src/ipa/raspberrypi/controller/rpi/focus.hpp b/src/ipa/raspberrypi/controller/rpi/focus.hpp
> new file mode 100644
> index 00000000..d53401f7
> --- /dev/null
> +++ b/src/ipa/raspberrypi/controller/rpi/focus.hpp
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> + *
> + * focus.hpp - focus algorithm
> + */
> +#pragma once
> +
> +#include "../algorithm.hpp"
> +#include "../metadata.hpp"
> +
> +/*
> + * The "focus" algorithm. All it does it print out a version of the
> + * focus contrast measure; there is no actual auto-focus mechanism to
> + * control.
> + */
> +
> +namespace RPi {
> +
> +class Focus : public Algorithm
> +{
> +public:
> +	Focus(Controller *controller);
> +	char const *Name() const override;
> +	void Read(boost::property_tree::ptree const &params) override;
> +	void Process(StatisticsPtr &stats, Metadata *image_metadata) override;
> +private:
> +	bool print_;
> +};
> +
> +} /* namespace RPi */
> diff --git a/src/ipa/raspberrypi/data/imx477.json b/src/ipa/raspberrypi/data/imx477.json
> index dce5234f..389e8ce8 100644
> --- a/src/ipa/raspberrypi/data/imx477.json
> +++ b/src/ipa/raspberrypi/data/imx477.json
> @@ -412,5 +412,9 @@
>      "rpi.sharpen":
>      {
>  
> +    },
> +    "rpi.focus":
> +    {
> +	"print": 1
>      }
>  }
> diff --git a/src/ipa/raspberrypi/meson.build b/src/ipa/raspberrypi/meson.build
> index 697902e9..9445cd09 100644
> --- a/src/ipa/raspberrypi/meson.build
> +++ b/src/ipa/raspberrypi/meson.build
> @@ -29,6 +29,7 @@ rpi_ipa_sources = files([
>      'controller/rpi/awb.cpp',
>      'controller/rpi/sharpen.cpp',
>      'controller/rpi/black_level.cpp',
> +    'controller/rpi/focus.cpp',
>      'controller/rpi/geq.cpp',
>      'controller/rpi/noise.cpp',
>      'controller/rpi/lux.cpp',

-- 
Regards,

Laurent Pinchart