eVision.EMatrixCodeReader Class Reference

A eVision.EMatrixCodeReader.__init__ instance is a tool that processes an ROI and returns a eVision.EMatrixCode instance. More...

Public Member Functions
None	__init__ (self)
	Default constructor for eVision.EMatrixCodeReader objects.
eVision.EMatrixCode	Read (self, eVision.EROIBW8 roi)
	Tries to locate, decode and read the Data Matrix code in the given ROI.
None	Reset (self)
	Resets the parameter search space to its default: the full range of all parameters.
eVision.EMatrixCode	Learn (self, eVision.EROIBW8 roi)
	Tries to locate, decode and read the Data Matrix code in the given ROI.
eVision.EMatrixCode	LearnMore (self, eVision.EROIBW8 roi)
	Tries to locate, decode and read the Data Matrix code in the given ROI.
None	Load (self, eVision.ESerializer|None serializer)
	Saves a eVision.EMatrixCodeReader.
None	Load (self, str path)
	Saves a eVision.EMatrixCodeReader.
None	Save (self, eVision.ESerializer|None serializer)
	Loads a eVision.EMatrixCodeReader.
None	Save (self, str path)
	Loads a eVision.EMatrixCodeReader.
None	SetLearnMaskElement (self, eVision.ELearnParam index, bool value)
	Allows to choose which decoded parameters are learnt when the eVision.EMatrixCodeReader.Learn or eVision.EMatrixCodeReader.LearnMore methods are called.
bool	GetLearnMaskElement (self, eVision.ELearnParam index)
	Allows to know which decoded parameters are learnt when the eVision.EMatrixCodeReader.Learn or eVision.EMatrixCodeReader.LearnMore methods are called.
None	SetIso29158CalibrationParameters (self, float Rcal, float MLcal, float SRcal, float SRtarget)
	Sets ISO/IEC 29158 calibration paramters.
eVision.ESearchParamsType	SearchParams (self)
	Parameter space that the algorithm uses to read a Data Matrix code from an ROI.
bool	ComputeGrading (self)
	Allows to choose whether the grading properties of the eVision.EMatrixCode object will be computed by the eVision.EMatrixCodeReader.Reset, eVision.EMatrixCodeReader.Read or eVision.EMatrixCodeReader.LearnMore methods.
	ComputeGrading (self, bool value)
	Allows to choose whether the grading properties of the eVision.EMatrixCode object will be computed by the eVision.EMatrixCodeReader.Reset, eVision.EMatrixCodeReader.Read or eVision.EMatrixCodeReader.LearnMore methods.
float	MinimumPrintGrowth (self)
	Minimum reference value in use for normalization of the PrintGrowth quality indicator.
	MinimumPrintGrowth (self, float value)
	Minimum reference value in use for normalization of the PrintGrowth quality indicator.
float	MaximumPrintGrowth (self)
	Maximum reference value in use for normalization of the PrintGrowth quality indicator.
	MaximumPrintGrowth (self, float value)
	Maximum reference value in use for normalization of the PrintGrowth quality indicator.
float	NominalPrintGrowth (self)
	Nominal reference value in use for normalization of the PrintGrowth quality indicator.
	NominalPrintGrowth (self, float value)
	Nominal reference value in use for normalization of the PrintGrowth quality indicator.
int	TimeOut (self)
	Time-out for the eVision.EMatrixCodeReader.Learn, eVision.EMatrixCodeReader.LearnMore and eVision.EMatrixCodeReader.Read methods.
	TimeOut (self, int value)
	Time-out for the eVision.EMatrixCodeReader.Learn, eVision.EMatrixCodeReader.LearnMore and eVision.EMatrixCodeReader.Read methods.
float	MaxHeightWidthRatio (self)
	Maximum value for a Data Matrix aspect ratio.
	MaxHeightWidthRatio (self, float value)
	Maximum value for a Data Matrix aspect ratio.

Detailed Description

A eVision.EMatrixCodeReader.__init__ instance is a tool that processes an ROI and returns a eVision.EMatrixCode instance.

Remarks:

A eVision.EMatrixCodeReader.__init__ has properties that allow customizing the reading process. One of these properties is eVision.EMatrixCodeReader.SearchParams, which is an instance of eVision.ESearchParamsType. This object embeds the parameter space where a Data Matrix code will be searched and has an interface of its own. The eVision.EMatrixCodeReader.__init__ class is found in the Euresys namespace

License(s): EasyMatrixCode

Deprecated

Deprecated, use eVision.EasyMatrixCode2.EMatrixCodeReader instead.

Deprecated in version 23.12. Scheduled to be removed in version 27.6.

Constructor & Destructor Documentation

__init__()

None eVision.EMatrixCodeReader.__init__

(

self

)

Default constructor for eVision.EMatrixCodeReader objects.

Member Function Documentation

ComputeGrading() [1/2]

bool eVision.EMatrixCodeReader.ComputeGrading

(

self

)

Allows to choose whether the grading properties of the eVision.EMatrixCode object will be computed by the eVision.EMatrixCodeReader.Reset, eVision.EMatrixCodeReader.Read or eVision.EMatrixCodeReader.LearnMore methods.

Remarks:

Default: false.

ComputeGrading() [2/2]

eVision.EMatrixCodeReader.ComputeGrading	(		self,
		bool	value )

Allows to choose whether the grading properties of the eVision.EMatrixCode object will be computed by the eVision.EMatrixCodeReader.Reset, eVision.EMatrixCodeReader.Read or eVision.EMatrixCodeReader.LearnMore methods.

Remarks:

Default: false.

GetLearnMaskElement()

bool eVision.EMatrixCodeReader.GetLearnMaskElement	(		self,
		eVision.ELearnParam	index )

Allows to know which decoded parameters are learnt when the eVision.EMatrixCodeReader.Learn or eVision.EMatrixCodeReader.LearnMore methods are called.

Parameters

index

Parameter identifier, as defined in eVision.ELearnParam

Learn()

eVision.EMatrixCode eVision.EMatrixCodeReader.Learn	(		self,
		eVision.EROIBW8	roi )

Tries to locate, decode and read the Data Matrix code in the given ROI.

Remarks:

If successful, it adds the parameters of the Data Matrix code found into the internal learning database. The decoding results can be found in the returned eVision.EMatrixCode object. The addition of the parameters of the Data Matrix code found into the internal learning database means that subsequent Read operations will be faster, but can only be performed on similar Data Matrix codes/conditions. Only the parameters that are tagged for learning are remembered for the subsequent eVision.EMatrixCodeReader.Read operations (see eVision.EMatrixCodeReader.SetLearnMaskElement). See the eVision.EMatrixCode.Found property for information about the outcome of the Learn process.

Parameters

roi	ROI in which the Data Matrix has to be found.

LearnMore()

eVision.EMatrixCode eVision.EMatrixCodeReader.LearnMore	(		self,
		eVision.EROIBW8	roi )

Tries to locate, decode and read the Data Matrix code in the given ROI.

Remarks:

If successful, it cumulates the parameters of the Data Matrix code found with those already present in the internal learning database. The decoding results can be found in the returned eVision.EMatrixCode object. The cumulation of the parameters of the Data Matrix code found with those already present in the internal learning database means that subsequent Read operations will be faster, but can only be performed on similar Data Matrix codes/conditions. Only the parameters that are tagged for learning are remembered for the subsequent eVision.EMatrixCodeReader.Read operations (see eVision.EMatrixCodeReader.SetLearnMaskElement). See the eVision.EMatrixCode.Found property for information about the outcome of the LearnMore process.

Parameters

roi	ROI in which the Data Matrix has to be found.

Load() [1/2]

None eVision.EMatrixCodeReader.Load	(		self,
		eVision.ESerializer | None	serializer )

Saves a eVision.EMatrixCodeReader.

The given ESerializer must have been created for writing.

Parameters

serializer

The serializer.

Load() [2/2]

None eVision.EMatrixCodeReader.Load	(		self,
		str	path )

Saves a eVision.EMatrixCodeReader.

The given ESerializer must have been created for writing.

Parameters

path	A string containing the full path to the file.

MaxHeightWidthRatio() [1/2]

float eVision.EMatrixCodeReader.MaxHeightWidthRatio

(

self

)

Maximum value for a Data Matrix aspect ratio.

Remarks:

This property allows controlling what kind of objects are considered as potential MatrixCode instances in the image. When objects are found in the image, only those where the bounding box has an aspect ratio smaller than this value are taken into account for digitization and decoding. The default value is 3.8, and should be adjusted if the MatrixCode cells in your image are non-square, or if your matrix code uses a very non-square symbology such as 32x8. The supplied value must lie between 0.0 and 5.0.

MaxHeightWidthRatio() [2/2]

eVision.EMatrixCodeReader.MaxHeightWidthRatio	(		self,
		float	value )

Maximum value for a Data Matrix aspect ratio.

Remarks:

This property allows controlling what kind of objects are considered as potential MatrixCode instances in the image. When objects are found in the image, only those where the bounding box has an aspect ratio smaller than this value are taken into account for digitization and decoding. The default value is 3.8, and should be adjusted if the MatrixCode cells in your image are non-square, or if your matrix code uses a very non-square symbology such as 32x8. The supplied value must lie between 0.0 and 5.0.

MaximumPrintGrowth() [1/2]

float eVision.EMatrixCodeReader.MaximumPrintGrowth

(

self

)

Maximum reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 2.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

MaximumPrintGrowth() [2/2]

eVision.EMatrixCodeReader.MaximumPrintGrowth	(		self,
		float	value )

Maximum reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 2.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

MinimumPrintGrowth() [1/2]

float eVision.EMatrixCodeReader.MinimumPrintGrowth

(

self

)

Minimum reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 0.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

MinimumPrintGrowth() [2/2]

eVision.EMatrixCodeReader.MinimumPrintGrowth	(		self,
		float	value )

Minimum reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 0.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

NominalPrintGrowth() [1/2]

float eVision.EMatrixCodeReader.NominalPrintGrowth

(

self

)

Nominal reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 1.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

NominalPrintGrowth() [2/2]

eVision.EMatrixCodeReader.NominalPrintGrowth	(		self,
		float	value )

Nominal reference value in use for normalization of the PrintGrowth quality indicator.

Remarks:

Default: 1.0. After the standard, parameter PrintGrowth must be computed as normalized value related to three references: minimum, nominal and maximum values have to be provided. Parameter MeasuredPrintGrowth is the raw, un-normalized print quality parameter. It is computed as the measured area of the active cells over the area of ideal square cells, having sides equal to the pitches (such cells perfectly tile the symbol). Its value typically is on the order of unity. The PrintGrowth is derived from the MeasuredPrintGrowth by means of the three normalization parameters.

Read()

eVision.EMatrixCode eVision.EMatrixCodeReader.Read	(		self,
		eVision.EROIBW8	roi )

Tries to locate, decode and read the Data Matrix code in the given ROI.

Remarks:

The decoding results can be found in the returned eVision.EMatrixCode object. See the eVision.EMatrixCode.Found property for information about the outcome of the Read process.

Note

This function throws an exception if the matrix code in the given ROI can not be read.

Parameters

roi	ROI in which the Data Matrix has to be found.

Reset()

None eVision.EMatrixCodeReader.Reset

(

self

)

Resets the parameter search space to its default: the full range of all parameters.

Remarks:

This does not modify the learning mask.

Save() [1/2]

None eVision.EMatrixCodeReader.Save	(		self,
		eVision.ESerializer | None	serializer )

Loads a eVision.EMatrixCodeReader.

The given ESerializer must have been created for reading.

Parameters

serializer

The eVision.ESerializer object that is read from.

Save() [2/2]

None eVision.EMatrixCodeReader.Save	(		self,
		str	path )

Loads a eVision.EMatrixCodeReader.

The given ESerializer must have been created for reading.

Parameters

path	A string containing the full path to the file.

SearchParams()

eVision.ESearchParamsType eVision.EMatrixCodeReader.SearchParams

(

self

)

Parameter space that the algorithm uses to read a Data Matrix code from an ROI.

Remarks:

It can be modified through automatic learning (using the eVision.EMatrixCodeReader.Learn or eVision.EMatrixCodeReader.LearnMore methods) or by using eVision.EMatrixCodeReader.SearchParams properties and methods.

SetIso29158CalibrationParameters()

None eVision.EMatrixCodeReader.SetIso29158CalibrationParameters	(		self,
		float	Rcal,
		float	MLcal,
		float	SRcal,
		float	SRtarget )

Sets ISO/IEC 29158 calibration paramters.

Parameters

Rcal	Reported reflectance value, from a calibration standard.
MLcal	Mean of the light from a histogram of the calibrated standard.
SRcal	System response parameters(such as exposure and/or again) used to create an image of the calibration standard.
SRtarget	System response parameters(such as exposure and/or again) used to create an image of the symbole under test.

SetLearnMaskElement()

None eVision.EMatrixCodeReader.SetLearnMaskElement	(		self,
		eVision.ELearnParam	index,
		bool	value )

Allows to choose which decoded parameters are learnt when the eVision.EMatrixCodeReader.Learn or eVision.EMatrixCodeReader.LearnMore methods are called.

Remarks:

In order to enable a parameter for learning, you need to set corresponding item of LearnMask to true. Default: all items are set to true.

Parameters

index	Parameter identifier, as defined in eVision.ELearnParam.
value	true to enable the parameter for learning.

TimeOut() [1/2]

int eVision.EMatrixCodeReader.TimeOut

(

self

)

Time-out for the eVision.EMatrixCodeReader.Learn, eVision.EMatrixCodeReader.LearnMore and eVision.EMatrixCodeReader.Read methods.

Remarks:

If the processing time of one of these functions becomes longer than the set time-out, the processing is stopped and an exception is thrown. In that case, the error code of the exception is eVision.EError.TimeoutReached. The time-out is set in microseconds. This time-out is not a real time-out. The processing is stopped as soon as possible after the time-out has been reached. This means that the time elapsed effectively in the method can be greater than the time-out in itself.

TimeOut() [2/2]

eVision.EMatrixCodeReader.TimeOut	(		self,
		int	value )

Time-out for the eVision.EMatrixCodeReader.Learn, eVision.EMatrixCodeReader.LearnMore and eVision.EMatrixCodeReader.Read methods.

Remarks:

If the processing time of one of these functions becomes longer than the set time-out, the processing is stopped and an exception is thrown. In that case, the error code of the exception is eVision.EError.TimeoutReached. The time-out is set in microseconds. This time-out is not a real time-out. The processing is stopped as soon as possible after the time-out has been reached. This means that the time elapsed effectively in the method can be greater than the time-out in itself.