diff options
| -rw-r--r-- | src/ipa/libipa/camera_sensor_helper.cpp | 38 | ||||
| -rw-r--r-- | src/ipa/libipa/camera_sensor_helper.h | 3 |
2 files changed, 41 insertions, 0 deletions
diff --git a/src/ipa/libipa/camera_sensor_helper.cpp b/src/ipa/libipa/camera_sensor_helper.cpp index 782ff990..82c795ea 100644 --- a/src/ipa/libipa/camera_sensor_helper.cpp +++ b/src/ipa/libipa/camera_sensor_helper.cpp @@ -48,6 +48,33 @@ namespace ipa { */ /** + * \fn CameraSensorHelper::blackLevel() + * \brief Fetch the black level of the sensor + * + * This function returns the black level of the sensor scaled to a 16bit pixel + * width. If it is unknown an empty optional is returned. + * + * \todo Fill the blanks and add pedestal values for all supported sensors. Once + * done, drop the std::optional<>. + * + * Black levels are typically the result of the following phenomena: + * - Pedestal added by the sensor to pixel values. They are typically fixed, + * sometimes programmable and should be reported in datasheets (but + * documentation is not always available). + * - Dark currents and other physical effects that add charge to pixels in the + * absence of light. Those can depend on the integration time and the sensor + * die temperature, and their contribution to pixel values depend on the + * sensor gains. + * + * The pedestal is usually the value with the biggest contribution to the + * overall black level. In most cases it is either known before or in rare cases + * (there is not a single driver with such a control in the linux kernel) can be + * queried from the sensor. This function provides that fixed, known value. + * + * \return The black level of the sensor, or std::nullopt if not known + */ + +/** * \brief Compute gain code from the analogue gain absolute value * \param[in] gain The real gain to pass * @@ -205,6 +232,11 @@ double CameraSensorHelper::gain(uint32_t gainCode) const */ /** + * \var CameraSensorHelper::blackLevel_ + * \brief The black level of the sensor + */ + +/** * \var CameraSensorHelper::gainType_ * \brief The analogue gain model type */ @@ -396,6 +428,8 @@ class CameraSensorHelperImx219 : public CameraSensorHelper public: CameraSensorHelperImx219() { + /* From datasheet: 64 at 10bits. */ + blackLevel_ = 4096; gainType_ = AnalogueGainLinear; gainConstants_.linear = { 0, 256, -1, 256 }; } @@ -407,6 +441,8 @@ class CameraSensorHelperImx258 : public CameraSensorHelper public: CameraSensorHelperImx258() { + /* From datasheet: 0x40 at 10bits. */ + blackLevel_ = 4096; gainType_ = AnalogueGainLinear; gainConstants_.linear = { 0, 512, -1, 512 }; } @@ -456,6 +492,8 @@ class CameraSensorHelperImx335 : public CameraSensorHelper public: CameraSensorHelperImx335() { + /* From datasheet: 0x32 at 10bits. */ + blackLevel_ = 3200; gainType_ = AnalogueGainExponential; gainConstants_.exp = { 1.0, expGainDb(0.3) }; } diff --git a/src/ipa/libipa/camera_sensor_helper.h b/src/ipa/libipa/camera_sensor_helper.h index 0d99073b..ac276e27 100644 --- a/src/ipa/libipa/camera_sensor_helper.h +++ b/src/ipa/libipa/camera_sensor_helper.h @@ -10,6 +10,7 @@ #include <stdint.h> #include <memory> +#include <optional> #include <string> #include <vector> @@ -25,6 +26,7 @@ public: CameraSensorHelper() = default; virtual ~CameraSensorHelper() = default; + std::optional<int16_t> blackLevel() const { return blackLevel_; } virtual uint32_t gainCode(double gain) const; virtual double gain(uint32_t gainCode) const; @@ -51,6 +53,7 @@ protected: AnalogueGainExpConstants exp; }; + std::optional<int16_t> blackLevel_; AnalogueGainType gainType_; AnalogueGainConstants gainConstants_; |