CharacterDefinition class

A class that defines the characteristics and properties of a single character for OCR processing.

The CharacterDefinition class stores various attributes of a character including its visual representation through template artifacts, structural properties like enclosures, and categorical information such as whether it's a letter, digit, or punctuation mark.

Example:

final charDef = CharacterDefinition(
  character: 'A',
  isLetter: true,
  matrices: [Artifact(...)],
);

Key features:

Supports JSON serialization/deserialization
Stores multiple template artifacts of the character
Tracks character properties like enclosures and line presence
Categorizes characters (letter, digit, punctuation, etc.)
Maintains standard template dimensions (60x40)

This class is fundamental to the Textify OCR system, providing the template definitions used for character recognition and matching.

Constructors

CharacterDefinition({required String character, int enclosures = 0, bool isAmount = false, bool isDate = false, bool isDigit = false, bool isLetter = false, bool isPunctuation = false, bool lineLeft = false, bool lineRight = false, List<Artifact> matrices = const []}): Creates a new CharacterDefinition instance.
CharacterDefinition.fromJson(Map<String, dynamic> json): Creates a CharacterDefinition from a JSON map.
factory
CharacterDefinition.fromJsonString(String jsonString): Creates a CharacterDefinition from a JSON string.
factory

Properties

averageColHistogram → List<double>: Returns the average column histogram across all template matrices.
no setter
averageRowHistogram → List<double>: Returns the average row histogram across all template matrices.
no setter
character → String: The character being defined.
final
enclosures → int: The number of enclosures for this character.
final
hashCode → int: The hash code for this object.
no setterinherited
isAmount → bool: Indicates if this character is used in monetary amounts.
final
isDate → bool: Indicates if this character is commonly used in date representations.
final
isDigit → bool: Indicates if this character is a numerical digit.
final
isLetter → bool: Indicates if this character is an alphabetic letter.
final
isPunctuation → bool: Indicates if this character is a punctuation mark.
final
lineLeft → bool: Indicates if the character has a left vertical line as part of its shape.
final
lineRight → bool: Indicates if the character has a right vertical line as part of its shape.
final
matrices → List<Artifact>: List of matrices representing this character's visual pattern.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

histogramSimilarity(List<int> inputColHist, List<int> inputRowHist) → double: Computes histogram similarity between this template and an input artifact.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toJson() → Map<String, dynamic>: Converts this CharacterDefinition to a JSON map.
toJsonString() → String: Converts this CharacterDefinition to a JSON string.
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Constants

templateHeight → const int: The height of the character template.
templateWidth → const int: The width of the character template.