do_ocr_multi_class_knnT_do_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn (Operator)

Name

do_ocr_multi_class_knnT_do_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn — Classify multiple characters with an k-NN classifier.

Signature

do_ocr_multi_class_knn(Character, Image : : OCRHandle : Class, Confidence)

Description

do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn computes the best class for each of the characters given by the regions CharacterCharacterCharacterCharactercharactercharacter and the gray values ImageImageImageImageimageimage with the k-NN classifier OCRHandleOCRHandleOCRHandleOCRHandleOCRHandleocrhandle and returns the classes in ClassClassClassClassclassValclass and the corresponding confidence of the classes in ConfidenceConfidenceConfidenceConfidenceconfidenceconfidence. The confidences lie between 0.0 and 1.0. The larger the value, the more reliable is the classification of the single characters. In contrast to do_ocr_single_class_knndo_ocr_single_class_knnDoOcrSingleClassKnnDoOcrSingleClassKnnDoOcrSingleClassKnndo_ocr_single_class_knn, do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn can classify multiple characters in one call, and therefore typically is faster than a loop that uses do_ocr_single_class_knndo_ocr_single_class_knnDoOcrSingleClassKnnDoOcrSingleClassKnnDoOcrSingleClassKnndo_ocr_single_class_knn to classify single characters. However, do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn can only return the best class of each character.

Before calling do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn, the classifier must be trained with trainf_ocr_class_knntrainf_ocr_class_knnTrainfOcrClassKnnTrainfOcrClassKnnTrainfOcrClassKnntrainf_ocr_class_knn.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.

Parameters

CharacterCharacterCharacterCharactercharactercharacter (input_object) region(-array) → object

Characters to be recognized.

ImageImageImageImageimageimage (input_object) singlechannelimage → object (byte / uint2)

Gray values of the characters.

OCRHandleOCRHandleOCRHandleOCRHandleOCRHandleocrhandle (input_control) ocr_knn → (handle)

Handle of the k-NN classifier.

ClassClassClassClassclassValclass (output_control) string(-array) → (string)

Result of classifying the characters with the k-NN.

Number of elements: Class == Character

ConfidenceConfidenceConfidenceConfidenceconfidenceconfidence (output_control) real(-array) → (real)

Confidence of the class of the characters.

Number of elements: Confidence == Character

Result

If the parameters are valid, the operator do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn returns the value 2 ( H_MSG_TRUE) . If necessary, an exception is raised.