eVision.ELineDetector Class Reference

Detects straight lines in a BW8 image using Hough transform. More...

Public Member Functions
None	__init__ (self, eVision.ELineDetector other)
	Copy operator.
None	__init__ (self)
	Constructs an eVision.ELineDetector.__init__ with all parameters explicitly specified.
None	__init__ (self, float rho, float theta, int threshold, float minLineLength, float maxLineGap, float angleThresholdDegrees)
	Copy operator.
None	Save (self, str path)
	Saves the detector configuration to a file.
None	Save (self, eVision.ESerializer|None serializer)
	Saves the detector configuration to a serializer.
None	Load (self, str path)
	Loads a detector configuration from a file.
None	Load (self, eVision.ESerializer|None serializer)
	Loads a detector configuration from a serializer.
list[eVision._eVision.ELine]	Detect (self, eVision.EROIBW8 image)
	Detects straight lines in the given BW8 image.
list[eVision._eVision.ELine]	Detect (self, eVision.EROIBW8 image, eVision.ERegion region, eVision.EFrame frame)
	Detects lines in the area of the image covered by region (transformed to sensor coordinates via frame), then maps results back to local frame coordinates.
list[eVision._eVision.ELine]	Detect (self, eVision.EROIBW8 image, eVision.ERegion region)
	Detects lines in the area of the image covered by region.
list[eVision._eVision.ELine]	Detect (self, eVision.EROIBW8 image, eVision.EFrame frame)
	Detects lines in the image and maps results to local frame coordinates via frame.
list[eVision._eVision.ELine]	Detect (self, eVision.ERegion region, eVision.EFrame frame)
	Transforms region to sensor coordinates via frame, converts it to a binary image, detects lines, then maps results back to local frame coordinates.
list[eVision._eVision.ELine]	Detect (self, eVision.ERegion region)
	Converts region to a binary image and detects lines in it.
None	StopProcess (self)
	Thread-safe.

Properties
	RadialBinSize = property(_RadialBinSize__getter, _RadialBinSize__setter)
	Distance resolution of the accumulator in pixels.
	AngularBinSize = property(_AngularBinSize__getter, _AngularBinSize__setter)
	Angle resolution of the accumulator in degrees.
	MinNumVotes = property(_MinNumVotes__getter, _MinNumVotes__setter)
	Minimum number of votes to qualify as a line.
	MinLineLength = property(_MinLineLength__getter, _MinLineLength__setter)
	Minimum length of a detected line segment in pixels.
	MaxLineGap = property(_MaxLineGap__getter, _MaxLineGap__setter)
	Maximum gap between two collinear segments to still merge them into one line.
	AngleThreshold = property(_AngleThreshold__getter, _AngleThreshold__setter)
	Maximum angular difference in degrees between two segments to consider them part of the same line.
	SegmentsBeforeMerging = property(_SegmentsBeforeMerging__getter, None)
	Returns the raw line segments that were merged to build the lines, as returned by the last call to eVision.ELineDetector.Detect.

Detailed Description

Detects straight lines in a BW8 image using Hough transform.

Remarks:

License(s): EasyImage

Constructor & Destructor Documentation

__init__() [1/3]

None eVision.ELineDetector.__init__	(		self,
		eVision.ELineDetector	other )

Copy operator.

Parameters

other

Another eVision.ELineDetector.

__init__() [2/3]

None eVision.ELineDetector.__init__

(

self

)

Constructs an eVision.ELineDetector.__init__ with all parameters explicitly specified.

__init__() [3/3]

None eVision.ELineDetector.__init__	(		self,
		float	rho,
		float	theta,
		int	threshold,
		float	minLineLength,
		float	maxLineGap,
		float	angleThresholdDegrees )

Copy operator.

Member Function Documentation

Detect() [1/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.ERegion	region )

Converts region to a binary image and detects lines in it.

Parameters

region

Region to convert and detect lines in.

Detect() [2/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.ERegion	region,
		eVision.EFrame	frame )

Transforms region to sensor coordinates via frame, converts it to a binary image, detects lines, then maps results back to local frame coordinates.

Parameters

region	Region in local frame coordinates.
frame	Frame used to transform region and results.

Detect() [3/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.EROIBW8	image )

Detects straight lines in the given BW8 image.

Parameters

image

Input BW8 image.

Detect() [4/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.EROIBW8	image,
		eVision.EFrame	frame )

Detects lines in the image and maps results to local frame coordinates via frame.

Parameters

image	Input BW8 image.
frame	Frame used to transform results to local coordinates.

Detect() [5/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.EROIBW8	image,
		eVision.ERegion	region )

Detects lines in the area of the image covered by region.

Parameters

image	Input BW8 image.
region	Region of interest in image coordinates.

Detect() [6/6]

list[eVision._eVision.ELine] eVision.ELineDetector.Detect	(		self,
		eVision.EROIBW8	image,
		eVision.ERegion	region,
		eVision.EFrame	frame )

Detects lines in the area of the image covered by region (transformed to sensor coordinates via frame), then maps results back to local frame coordinates.

Parameters

image	Input BW8 image.
region	Region of interest in local frame coordinates.
frame	Frame used to transform region and results.

Load() [1/2]

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

Loads a detector configuration from a serializer.

Parameters

serializer

Source serializer in read mode.

Load() [2/2]

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

Loads a detector configuration from a file.

Parameters

path	Path to the input file.

Save() [1/2]

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

Saves the detector configuration to a serializer.

Parameters

serializer

Target serializer in write mode.

Save() [2/2]

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

Saves the detector configuration to a file.

Parameters

path	Path to the output file.

StopProcess()

None eVision.ELineDetector.StopProcess

(

self

)

Thread-safe.

Requests the Detect call running on another thread to stop as soon as possible; it then returns no lines. The request is discarded when the next Detect call starts.

Property Documentation

AngleThreshold

eVision.ELineDetector.AngleThreshold = property(_AngleThreshold__getter, _AngleThreshold__setter)

static

Maximum angular difference in degrees between two segments to consider them part of the same line.

Default is 35°.

AngularBinSize

eVision.ELineDetector.AngularBinSize = property(_AngularBinSize__getter, _AngularBinSize__setter)

static

Angle resolution of the accumulator in degrees.

Default is 1.

MaxLineGap

eVision.ELineDetector.MaxLineGap = property(_MaxLineGap__getter, _MaxLineGap__setter)

static

Maximum gap between two collinear segments to still merge them into one line.

Default is 64.

MinLineLength

eVision.ELineDetector.MinLineLength = property(_MinLineLength__getter, _MinLineLength__setter)

static

Minimum length of a detected line segment in pixels.

Shorter segments are discarded. Default is 164.

MinNumVotes

eVision.ELineDetector.MinNumVotes = property(_MinNumVotes__getter, _MinNumVotes__setter)

static

Minimum number of votes to qualify as a line.

Default is 150.

RadialBinSize

eVision.ELineDetector.RadialBinSize = property(_RadialBinSize__getter, _RadialBinSize__setter)

static

Distance resolution of the accumulator in pixels.

Default is 1.

SegmentsBeforeMerging

eVision.ELineDetector.SegmentsBeforeMerging = property(_SegmentsBeforeMerging__getter, None)

static

Returns the raw line segments that were merged to build the lines, as returned by the last call to eVision.ELineDetector.Detect.