diff options
Diffstat (limited to 'src/ipa/libipa/camera_sensor_helper.cpp')
| -rw-r--r-- | src/ipa/libipa/camera_sensor_helper.cpp | 38 |
1 files changed, 38 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) }; } |