Operator Reference

HALCON Operator Reference / OCR / K-Nearest Neighbors
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trainf_ocr_class_knnT_trainf_ocr_class_knnTrainfOcrClassKnnTrainfOcrClassKnntrainf_ocr_class_knn (Operator)

trainf_ocr_class_knnT_trainf_ocr_class_knnTrainfOcrClassKnnTrainfOcrClassKnntrainf_ocr_class_knn — Trains an k-NN classifier for an OCR task.

Signature

trainf_ocr_class_knn( : : OCRHandle, TrainingFile, GenParamName, GenParamValue : )

Herror T_trainf_ocr_class_knn(const Htuple OCRHandle, const Htuple TrainingFile, const Htuple GenParamName, const Htuple GenParamValue)

void TrainfOcrClassKnn(const HTuple& OCRHandle, const HTuple& TrainingFile, const HTuple& GenParamName, const HTuple& GenParamValue)

void HOCRKnn::TrainfOcrClassKnn(const HTuple& TrainingFile, const HTuple& GenParamName, const HTuple& GenParamValue) const

void HOCRKnn::TrainfOcrClassKnn(const HString& TrainingFile, const HTuple& GenParamName, const HTuple& GenParamValue) const

void HOCRKnn::TrainfOcrClassKnn(const char* TrainingFile, const HTuple& GenParamName, const HTuple& GenParamValue) const

void HOCRKnn::TrainfOcrClassKnn(const wchar_t* TrainingFile, const HTuple& GenParamName, const HTuple& GenParamValue) const   ( Windows only)

def trainf_ocr_class_knn(ocrhandle: HHandle, training_file: MaybeSequence[str], gen_param_name: Sequence[str], gen_param_value: Sequence[Union[int, str, float]]) -> None

Description

trainf_ocr_class_knntrainf_ocr_class_knnTrainfOcrClassKnnTrainfOcrClassKnntrainf_ocr_class_knn trains the k-NN classifier OCRHandleOCRHandleOCRHandleOCRHandleocrhandle with the training characters stored in the OCR training files given by TrainingFileTrainingFileTrainingFiletrainingFiletraining_file. The training files must have been created, e.g., using write_ocr_trainfwrite_ocr_trainfWriteOcrTrainfWriteOcrTrainfwrite_ocr_trainf, before calling trainf_ocr_class_knntrainf_ocr_class_knnTrainfOcrClassKnnTrainfOcrClassKnntrainf_ocr_class_knn. Please, note that training characters that have no corresponding class in the classifier OCRHandleOCRHandleOCRHandleOCRHandleocrhandle are discarded.

The following options may be set using GenParamNameGenParamNameGenParamNamegenParamNamegen_param_name and GenParamValueGenParamValueGenParamValuegenParamValuegen_param_value, respectively:

'num_trees'"num_trees""num_trees""num_trees""num_trees"

Sets the number of search trees. A higher number of trees improves the accuracy of the search, but also increases the runtime.

Default: 4.

'normalization'"normalization""normalization""normalization""normalization"

Activates the data normalization, if set to 'true'"true""true""true""true". This will change the stored training data permanently. Therefore, adding data after the training is not possible.

List of values: 'true'"true""true""true""true", 'false'"false""false""false""false".

Default: 'false'"false""false""false""false".

Execution Information

  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).
  • Multithreading scope: global (may be called from any thread).
  • Processed without parallelization.

This operator modifies the state of the following input parameter:

During execution of this operator, access to the value of this parameter must be synchronized if it is used across multiple threads.

Parameters

OCRHandleOCRHandleOCRHandleOCRHandleocrhandle (input_control, state is modified)  ocr_knn → HOCRKnn, HTupleHHandleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)

Handle of the k-NN classifier.

TrainingFileTrainingFileTrainingFiletrainingFiletraining_file (input_control)  filename.read(-array) → HTupleMaybeSequence[str]HTupleHtuple (string) (string) (HString) (char*)

Names of the training files.

Default: 'ocr.trf' "ocr.trf" "ocr.trf" "ocr.trf" "ocr.trf"

File extension: .trf, .otr

GenParamNameGenParamNameGenParamNamegenParamNamegen_param_name (input_control)  string-array → HTupleSequence[str]HTupleHtuple (string) (string) (HString) (char*)

Names of the generic parameters that can be adjusted for the k-NN classifier creation.

Default: []

List of values: 'normalization'"normalization""normalization""normalization""normalization", 'num_trees'"num_trees""num_trees""num_trees""num_trees"

GenParamValueGenParamValueGenParamValuegenParamValuegen_param_value (input_control)  number-array → HTupleSequence[Union[int, str, float]]HTupleHtuple (integer / string / real) (int / long / string / double) (Hlong / HString / double) (Hlong / char* / double)

Values of the generic parameters that can be adjusted for the k-NN classifier creation.

Default: []

Suggested values: 4, 5, 'false'"false""false""false""false", 'true'"true""true""true""true"

Example (HDevelop)

* Train an OCR classifier
read_ocr_trainf_names ('ocr.trf', CharacterNames, CharacterCount)
create_ocr_class_knn (8, 10, 'constant', 'default', CharacterNames, [],\
                      [], OCRHandle)
trainf_ocr_class_knn (OCRHandle, 'ocr.trf', [], [])
write_ocr_class_knn (OCRHandle, 'ocr.omc')

Result

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

Possible Predecessors

create_ocr_class_knncreate_ocr_class_knnCreateOcrClassKnnCreateOcrClassKnncreate_ocr_class_knn, write_ocr_trainfwrite_ocr_trainfWriteOcrTrainfWriteOcrTrainfwrite_ocr_trainf, append_ocr_trainfappend_ocr_trainfAppendOcrTrainfAppendOcrTrainfappend_ocr_trainf, write_ocr_trainf_imagewrite_ocr_trainf_imageWriteOcrTrainfImageWriteOcrTrainfImagewrite_ocr_trainf_image

Possible Successors

do_ocr_single_class_knndo_ocr_single_class_knnDoOcrSingleClassKnnDoOcrSingleClassKnndo_ocr_single_class_knn, do_ocr_multi_class_knndo_ocr_multi_class_knnDoOcrMultiClassKnnDoOcrMultiClassKnndo_ocr_multi_class_knn

Alternatives

read_ocr_class_knnread_ocr_class_knnReadOcrClassKnnReadOcrClassKnnread_ocr_class_knn

See also

train_class_knntrain_class_knnTrainClassKnnTrainClassKnntrain_class_knn

Module

OCR/OCV

ClassesClasses | | Operators