Documentation for Auto PSIM 1.0.1.

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The settings panel of the VT module object contains the following interface elements:

Parameters of the VT module object are described in the table.

№ 

Parameter name

Method for setting the parameter value 

Description

Representation

Default value

Value range

1

Zooming

Set the checkbox

Reduces the frame size while recognizing depending on the Zone width parameter value

Boolean type

Clear

Set—the frame size is reduced during recognition

Clear—the frame size isn't reduced during recognition

2

The Advanced settings group
Number of streams for frame processingEnter the value in the fieldSets maximum recognition streamsNon-negative integer00-255
 License typeSelect the value from the drop-down listSets the used license typeList of license typesdefault

default—the license type is determined automatically

fast (25 fps)

slow (6 fps)

Generate unrecognized LP eventSet the checkbox

Enables the generation of the NOT DETECTED event for vehicles which number could not be recognized

Boolean typeClear

Set—if the license plate is unrecognized, the corresponding event is generated
Clear—if the license plate is unrecognized, then such a vehicle is ignored

3Fine tuning of SDKClick the buttonOpens the Fine tuning of SDK (see the table below)NANANA

Attention!

You must perform fine tuning of SDK only with the help of AxxonSoft specialists!

Parameter values that are not specified in this table must not be changed!

ParameterDescription

VodiCTL_VPW_PLATE_RATIO_TYPE

Information about how much the initial image is reduced or increased in height. The default value is 0. There are three options available:

  1. No distortions
  2. Automatically depending on the image size
  3. User value

VodiCTL_VPW_IMAGE_THRESHOLD

Base level of image thresholding. The default value is 40

VodiCTL_VPW_IMAGE_BLUR

The parameter for internal use. The recommended value is 13

VodiCTL_VPW_ PLATE_EXTRA_ANGLE_ANALYSE

Enable/disable the angle analysis algorithm of the license plate image

VodiCTL_VPW_ PLATE_EXTRA_RANGES_ANALYSEEnable/disable the algorithm of a thorough search for license plate candidates

VodiCTL_VPW_PLATE_STAR_MAX

Maximum unrecognized characters on the license plate at which the result will still be considered the result of the recognition of the license plate

VodiCTL_VPW_PLATE_PROBABILITY_MIN

Minimum percentage of similarity between the recognition result and the corresponding license plate template at which this result can be considered the result of the recognition of the license plate. Using this parameter, the results obtained are filtered according to the authenticity

VodiCTL_VPW_PLATE_FILTER_ROFACTOR

The license plate filter coefficient by the so-called image density—ratio of white pixels to total pixels (first strategy). The type is unsigned. This coefficient is used for image thresholding and has the optimal values, which are determined by AutoSDK developers using their own test samples. The parameter is considered as a service one, and its value must be set according to the recommendations of technical support specialists

VodiCTL_VPW_PLATE_FILTER_RODROPFACTOR

The license plate filter coefficient by the so-called image density—ratio of white pixels to total pixels (second strategy). The type is unsigned. This coefficient is used for image thresholding and has the optimal values, which are determined by AutoSDK developers using their own test samples. The parameter is considered as a service one, and its value must be set according to the recommendations of technical support specialists

VodiCTL_VPW_PLATE_FILTER_SYMCOUNT

Enable/disable the algorithm of simple license plates filter by the minimum number of recognized characters on them. If the algorithm is enabled (the value of the parameter is greater than 0), the base search for characters on the license plate candidate (geometry, proportions) is performed. If fewer characters are recognized on the license plate candidate than specified in this parameter, this license plate candidate is not considered a license plate. That is, the value of this parameter is the minimum characters that must be present on the license plate candidate when the basic algorithm is used

VodiCTL_VPW_LOG_SETTINGS

Enable/disable logging of all recognition parameters

VodiCTL_VPW_PLATE_PRECISE_ANALYSE

Enable/disable precise image analysis. It increases the quality of recognition under adverse conditions (for example, if the characteristics/settings of the camera do not fully meet the requirements or in bad weather). It increases the processing time of the frame by 20-30%, depending on its size. Under normal conditions, this parameter does not affect the quality of recognition

VodiCTL_VPW_DYNAMIC_ENABLE

Enable/disable dynamics of license plate recognition (by default, the dynamics is enabled).

If the value is True, then tracking is enabled, and the license plate is recognized by the set of frames. If the value is False, then tracking is disabled, and the license plate is recognized by each frame separately without taking to account the previous ones, and the quality can vary from 0% to 100%

VodiCTL_VPW_DYNAMIC_OUTPUT_FRAMECOUNT

Number of frames required to display a license plate. The default value is 0. This is necessary, but not sufficient, for the first output of the result. This condition delays displaying from the first moment of recognition of the license plate in dynamics. The setting is designed to improve authenticity of the results, as well as to hide possible false events

VodiCTL_VPW_DYNAMIC_WITH_DUPLICATE

Enable/disable the periodic output of license plate recognition results

VodiCTL_VPW_DYNAMIC_OUTPUT_TIMEOUT

The minimum time required to monitor the license plate (in milliseconds) before displaying the recognition result to the user. This parameter can only be used when the “Dynamic” mode is on. In this mode, the track of the vehicle is monitored, and the user does not immediately receive the recognition result of the license plate, but after the time specified for this setting. In this case, the first recognition result will be replaced by the result of higher quality and subsequently displayed to the user. If parameter 0 is set for this value, the user gets the first result of recognizing the detected license plate. After the time specified in this parameter expires, the monitoring of the track of the license plate continues until it disappears from the frame

VodiCTL_VPW_DYNAMIC_OUTPUT_PERIOD

Time period (in milliseconds) over which the recognition result must be displayed to the user. This parameter can be used only if the VodiCTL_VPW_DYNAMIC_WITH_DUPLICATE parameter is set

VodiCTL_VPW_DYNAMIC_DURATION_WITHOUT_ACCESS

Maximum permissible absence time of the license plate in the monitoring area (in milliseconds). After this time, the license plate is considered lost and is displayed to the user with the set checkbox VodiF_RESULT_LOST

VodiCTL_VPW_DYNAMIC_COMPARABLE_TIME_MAX

Time interval (in milliseconds) that affects the algorithm for comparing the preliminary recognition results. That is, if the results fall within a given interval and the geometric distance between the license plates is small compared to the license plates size, then it is considered to be the same object

VodiCTL_VPW_DNN_DEVICES

A list of devices on which the deep neural network (DNN) computations is performed. The set of available devices is defined in the <Vodi/devType.h> file.

This parameter can also be set via the Windows environment variable: VPW_DNN_DEVICES={comma-separated list of devices}. For example: CPU, GPU, MYRIA

VodiCTL_VPW_PLATECANDS_METHODS

A variety of methods for obtaining the license plate candidates. Available methods:

  • VodiF_VPW_PLATECANDS_BY_MORPH is an old method;
  • VodiF_VPW_PLATECANDS_BY_DNN is a method based on deep neural networks (DNN);
  • VodiF_VPW_PLATECANDS_BY_2_DNN is a new method based on deep neural networks (DNN), it is set by default. We recommend using this method.

To ensure the operation in the VodiF_VPW_PLATECANDS_BY_2_DNN and VodiF_VPW_PLATECANDS_BY_DNN modes, it is important to correctly set the minimum size of the license plate on the image; the larger it is (for example, from 100 pixels or more), the higher the performance will be.

This parameter can also be set via the Windows environment variable: VPW_PLATECANDS_METHODS={number}. For example: 1, 2

VodiCTL_VPW_ANALYSE_LEVEL

The level of the license plate analysis. The following levels of analysis are available:

  • VodiK_VPW_PLATECANDS_ANALYSE—only license plate candidates are found at this level, that is, the rectangles of their areas;
  • VodiK_VPW_SYMCANDS_ANALYSE—the character candidates are also be found at this level, that is, the rectangles of their areas;
  • VodiK_VPW_TEXT_ANALYSE—the complete license plate analysis is performed at this level;
  • VodiK_VPW_TEMPLATE_ANALYSE—the found characters are also recognized at this level. Performs full license plate analysis, set by default
VodiCTL_VPW_PLATE_ANALYSE_METHODS

A variety of methods for analyzing the license plate candidates. Available methods:

  • VodiK_VPW_PLATE_ANALYSE_METHODS_DEFAULT,
  • VodiF_VPW_BLURAN,
  • VodiF_VPW_NAN,
  • VodiF_VPW_TMPLAN,
  • VodiF_VPW_DNNAN, 
  • VodiF_VPW_OTSUAN;
  • VodiF_VPW_DNN2AN is a new license plate analysis method based on deep neural networks (DNN). Set by default. We recommend using this method.

The VodiF_VPW_DNN2AN | VodiF_VPW_BLURAN | VodiF_VPW_DNNAN | VodiF_VPW_TMPLAN methods provide the highest number of correctly recognized results

VodiCTL_VPW_PLATE_DNN_FILTER_ENABLE

Enable/disable the filtering of license plate candidates by the deep neural network (DNN)

VodiCTL_VPW_TREAT_PLATECAND_AS_PLATE

Enable/disable the ability to consider each license plate candidate as a license plate. This means that if the analysis of a candidate was unsuccessful for any reason (for example, it was not possible to recognize the license plate), then such a candidate will not be lost, but will be given as a license plate, while some of the information will be missing, namely the pis_plate_variantc will be 0

VPW_RECOGN_OUTSIDE_PLATECAND

This Windows environment variable makes it possible to prohibit the analysis of a license plate outside the rectangular area (that is, a license plate candidate) found by the license plate detector. This is an experimental parameter and it can be removed later

VodiCTL_VPW_SEQUENTIAL_FLUSH_ENABLE

Enable/disable the ability to change the behavior of the VodiprincFlush operation. Without this parameter, the operation waits for the completion of the analysis of all frames, then transfers the results to the dynamics (if enabled), accumulates the dynamics results, performs the flush operation for the dynamics and finally returns the accumulated result.

With this parameter, the operation waits for the completion of the analysis of the earliest frame, then transfers its result to the dynamics (if enabled) and returns its result. Thus, to get all the results that are still being analyzed, it is necessary to sequentially call the VodiprincFlush operation while it returns the >=BoS_OK status

VodiCTL_VPW_TREAT_SYMBOLS_AS_TEXT

Allows you to interpret recognized characters as text if, for example, there are problems with template recognition or if the recognized license plates don't match known templates

VodiCTL_VPW_DYNAMIC_VELOCITY_MAXSystem parameters. It is strongly discouraged to change the default values
VodiCTL_VPW_DYNAMIC_COMPARABLE_SYMBOLS_MIN
VodiCTL_VPW_DYNAMIC_BEFORE_LOST_TRACK_TIME_MAX
VodiCTL_VPW_DYNAMIC_AFTER_LOST_TIME_MAX
VodiCTL_VPW_DYNAMIC_AFTER_LOST_FACTOR
VodiCTL_VPW_DYNAMIC_PLATE_LOCATION_MISMATCH_FACTOR
VodiCTL_VPW_DYNAMIC_COMPARABLE_TIME_FACTOR
VodiCTL_VPW_DYNAMIC_PLATE_LOCATION_MISMATCH_FACTOR2
VodiCTL_VPW_DYNAMIC_TRAC_LIMIT
VodiCTL_VPW_DYNAMIC_BEFORE_LOST_TRACK_FACTOR