Peak search algorithm

Focus search algorithms for optimal focus positioning. More...

Enumerations
enum	peak_afl_controller_algorithm {   PEAK_AFL_CONTROLLER_ALGORITHM_AUTO , PEAK_AFL_CONTROLLER_ALGORITHM_GOLDEN_RATIO_SEARCH , PEAK_AFL_CONTROLLER_ALGORITHM_HILL_CLIMBING_SEARCH , PEAK_AFL_CONTROLLER_ALGORITHM_GLOBAL_SEARCH ,   PEAK_AFL_CONTROLLER_ALGORITHM_FULL_SCAN }
	Focus search algorithms. More...

Functions
PEAK_AFL_API_STATUS	peak_afl_AutoController_Algorithm_IsSupported (peak_afl_controller_handle controller, peak_afl_BOOL8 *supported)
	Check if setting an algorithm is supported for a controller.
PEAK_AFL_API_STATUS	peak_afl_AutoController_Algorithm_Set (peak_afl_controller_handle controller, peak_afl_controller_algorithm algorithm)
	Set the used algorithm for a controller.
PEAK_AFL_API_STATUS	peak_afl_AutoController_Algorithm_Get (peak_afl_controller_handle controller, peak_afl_controller_algorithm *algorithm)
	Get the used algorithm for a controller.
PEAK_AFL_API_STATUS	peak_afl_AutoController_Algorithm_GetList (peak_afl_controller_handle controller, peak_afl_controller_algorithm *typeList, uint32_t *listSize)
	Get the list of supported algorithms for a controller.

Detailed Description

Focus search algorithms for optimal focus positioning.

Sets the algorithm for the maximum value search.

Note

If no maximum value can be found after 300 iterations, the search is aborted and the focus value is reset to the previous value.

• Golden Ratio Search: Within the preset interval range, the focus function repeatedly divides into new intervals using the Golden Ratio. The interval range is decreased with each new calculation. This process continues until the interval range is less than or equal to the set hysteresis.
• Hill Climbing Search: Within the preset interval range, the focus function scans the register values for a maximum with medium step width until two falling sharpness values occur at the last two steps. Based on these values and the step width, the interval range and step width are reduced and the scan is repeated within this interval. This process continues until the interval range is less than or equal to the set hysteresis.
• Global Search: Within the preset interval range, the focus function completely scans with medium step width and the maximum that occurred is memorized. Based on the maximum, the interval range and the step width are reduced and the scan is repeated within this interval. This process continues until the interval range is less than or equal to the set hysteresis.
• Full Scan: Within the preset interval range, the focus function scans with a constant step width for an optimal result (step width: hysteresis).

Enumeration Type Documentation

peak_afl_controller_algorithm

enum peak_afl_controller_algorithm

Focus search algorithms.

Defines the search algorithms used by auto focus controllers to find the optimal focus position. Different algorithms offer trade-offs between speed, accuracy, and reliability in various conditions.

Note

Algorithm availability may depend on camera capabilities

See also

peak_afl_AutoController_Algorithm_Set()

peak_afl_AutoController_Algorithm_Get()

peak_afl_AutoController_Algorithm_IsSupported()

Enumerator
PEAK_AFL_CONTROLLER_ALGORITHM_AUTO	Automatic algorithm selection. Deprecated This value is deprecated. The automatic selection always defaults to the Golden Ratio algorithm. Use PEAK_AFL_CONTROLLER_ALGORITHM_GOLDEN_RATIO_SEARCH instead.
PEAK_AFL_CONTROLLER_ALGORITHM_GOLDEN_RATIO_SEARCH	Golden ratio search algorithm. Uses golden section search to efficiently find the focus peak. Provides fast convergence with good accuracy for most scenes. Requires fewer focus steps than full scan methods. Note Fast convergence (typically 8-12 steps) Good for real-time applications May struggle with multiple focus peaks or low contrast scenes
PEAK_AFL_CONTROLLER_ALGORITHM_HILL_CLIMBING_SEARCH	Hill climbing search algorithm. Iteratively moves focus position toward increasing sharpness values. Good for fine-tuning focus around the optimal position. May get trapped in local maxima with complex scenes. Note Good for fine focus adjustments Fast for small focus corrections May fail with multiple focus peaks or noisy sharpness curves
PEAK_AFL_CONTROLLER_ALGORITHM_GLOBAL_SEARCH	Global search algorithm. Performs a comprehensive search across the focus range to find the global optimum. More robust against local maxima but slower than other methods. Best accuracy for complex scenes. Note Highest accuracy and reliability Handles multiple focus peaks well Slower than other algorithms (moderate speed) Best for critical applications where accuracy is paramount
PEAK_AFL_CONTROLLER_ALGORITHM_FULL_SCAN	Full range scan algorithm. Scans the entire focus range systematically to build a complete focus curve. Provides maximum accuracy but requires the most time. Ideal for laboratory, calibration, or non-real-time applications. Note Maximum accuracy possible Complete focus characterization across full range Slowest algorithm (full range scan) Best for laboratory, calibration, or quality control applications

Function Documentation

peak_afl_AutoController_Algorithm_Get()

PEAK_AFL_API_STATUS peak_afl_AutoController_Algorithm_Get	(	peak_afl_controller_handle	controller,
		peak_afl_controller_algorithm *	algorithm )

Get the used algorithm for a controller.

Retrieves the currently configured algorithm that the controller is using for automatic adjustments. This is the same algorithm that was previously set using peak_afl_AutoController_Algorithm_Set.

Parameters

[in]	controller	controller handle
[out]	algorithm	auto controller algorithm

Returns

PEAK_AFL_STATUS_SUCCESS Operation was successful; no error occurred.

PEAK_AFL_STATUS_NOT_INITIALIZED The library is not initialized.

PEAK_AFL_STATUS_INVALID_PARAMETER The argument is invalid.

PEAK_AFL_STATUS_NOT_SUPPORTED The function is not supported.

PEAK_AFL_STATUS_ERROR An unexpected internal error occurred.

Since

1.0

peak_afl_AutoController_Algorithm_GetList()

PEAK_AFL_API_STATUS peak_afl_AutoController_Algorithm_GetList	(	peak_afl_controller_handle	controller,
		peak_afl_controller_algorithm *	typeList,
		uint32_t *	listSize )

Get the list of supported algorithms for a controller.

Retrieves all algorithms that are supported by the specified controller. This function allows you to discover which algorithms are available before attempting to configure one. Different controllers may support different sets of algorithms based on their implementation and capabilities.

Uses the Two Staged Data Query principle: call first with NULL to get the required buffer size, then call again with an allocated buffer to retrieve the actual algorithm list.

To set a specific algorithm, see peak_afl_AutoController_Algorithm_Set.

Parameters

[in]	controller	controller handle
[out]	typeList	Pointer to a user allocated list of peak_afl_controller_algorithm. If this parameter is NULL, listSize will contain the needed count of typeList.
[in,out]	listSize	Size of typeList: typeList equal NULL: out: minimal size of listSize in count of peak_afl_controller_algorithm to hold the list typeList unequal NULL: in: size of the provided lastErrorMessage in counts of peak_afl_controller_algorithm out: number of peak_afl_controller_algorithm used by the function

Returns

PEAK_AFL_STATUS_SUCCESS Operation was successful; no error occurred.

PEAK_AFL_STATUS_NOT_INITIALIZED The library is not initialized.

PEAK_AFL_STATUS_INVALID_PARAMETER The argument is invalid.

PEAK_AFL_STATUS_BUFFER_TOO_SMALL The supplied buffer is too small.

PEAK_AFL_STATUS_NOT_SUPPORTED The function is not supported.

PEAK_AFL_STATUS_ERROR An unexpected internal error occurred.

Since

1.0

peak_afl_AutoController_Algorithm_IsSupported()

PEAK_AFL_API_STATUS peak_afl_AutoController_Algorithm_IsSupported	(	peak_afl_controller_handle	controller,
		peak_afl_BOOL8 *	supported )

Check if setting an algorithm is supported for a controller.

If supported is PEAK_AFL_TRUE algorithm is supported, otherwise it is unsupported.

Call peak_afl_AutoController_Algorithm_GetList to get a list of supported algorithms.

Parameters

[in]	controller	controller handle
[out]	supported	boolean if controller supports setting an algorithm

Returns

PEAK_AFL_STATUS_SUCCESS Operation was successful; no error occurred.

PEAK_AFL_STATUS_NOT_INITIALIZED The library is not initialized.

PEAK_AFL_STATUS_INVALID_PARAMETER The argument is invalid.

PEAK_AFL_STATUS_ERROR An unexpected internal error occurred.

Since

1.0

peak_afl_AutoController_Algorithm_Set()

PEAK_AFL_API_STATUS peak_afl_AutoController_Algorithm_Set	(	peak_afl_controller_handle	controller,
		peak_afl_controller_algorithm	algorithm )

Set the used algorithm for a controller.

Configures the algorithm that the controller will use for automatic adjustments. Different algorithms may provide different performance characteristics, accuracy, or speed. The choice of algorithm can significantly impact the controller's behavior and the quality of automatic adjustments.

The available algorithms depend on the controller type and implementation. To get a list of supported algorithms for this controller, call peak_afl_AutoController_Algorithm_GetList first.

Parameters

[in]	controller	controller handle
[in]	algorithm	auto controller algorithm

Returns

PEAK_AFL_STATUS_SUCCESS Operation was successful; no error occurred.

PEAK_AFL_STATUS_NOT_INITIALIZED The library is not initialized.

PEAK_AFL_STATUS_INVALID_PARAMETER The argument is invalid.

PEAK_AFL_STATUS_NOT_SUPPORTED The function is not supported.

PEAK_AFL_STATUS_ERROR An unexpected internal error occurred.

Since

1.0