select_grey__ ( Regions, Image : SelectedRegions : Features, Operation, Min, Max : )

Select regions based on gray value features.

The operator select_grey__ has a number of regions (Regions) as input. For each of these regions the features (Features) are calculated. If each (Operation = 'and') or at least one (Operation = 'or') of the calculated features is within the limits determined by the parameter, the region is transferred (duplicated) into the output. The parameter Image contains an image which returns the gray values for calculating the features.

Condition:

   Min[i] <= Features[i](Regions,Image) <= Max[i]
Possible values for Features:
  'mean'            mean gray value (see: intensity__)
  'deviation'       standard deviation of gray values (see: intensity__)
  'min'             minimum gray value (see: min_max__)
  'max'             maximum gray value (see: min_max__)
  'entropy'         entropy (see: entropy2__)
  'anisotropy'      anisotropy (see: entropy2__)


Attention

If only one feature is used the value of Operation is meaningless. Several features are processed in the order in which they are entered.


Parameters

Regions (input_object)
region-array -> object
Regions to be examined.

Image (input_object)
image -> object : byte / int2 / int4 / real
Gray value image.

SelectedRegions (output_object)
region-array -> object
Regions having features within the limits.

Features (input_control)
string(-array) -> string
Names of the features.
Default value: 'mean'
List of values: 'mean', 'min', 'max', 'deviation', 'entropy', 'anisotropy'

Operation (input_control)
string -> string
Logical connection of features.
Default value: 'and'
List of values: 'and', 'or'

Min (input_control)
number(-array) -> real / integer
Lower limit(s) of features.
Default value: 128.0
Suggested values: 0.5, 1.0, 10.0, 20.0, 50.0, 128.0, 255.0, 1000.0

Max (input_control)
number(-array) -> real / integer
Upper limit(s) of features.
Default value: 255.0
Suggested values: 0.5, 1.0, 10.0, 20.0, 50.0, 128.0, 255.0, 1000.0


Complexity

If F is the area of the region and N the number of features the runtime complexity is O(F * N).


Result

The operator select_grey__ returns the value TRUE if the input image has the defined gray values and the parameters are correct. The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:), the behavior in case of empty region is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.


Possible Predecessors

connection, mean__, entropy1__, sobel_amp, median_separate


Possible Successors

select_shape, select_grey__, shape_trans, reduce_domain, count_obj


See also

deviation__, entropy2__, intensity__, mean__, min_max__, select_obj



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