Operator Reference
trainf_ocr_class_svm (Operator)
trainf_ocr_class_svm
— Train an OCR classifier.
Signature
trainf_ocr_class_svm( : : OCRHandle, TrainingFile, Epsilon, TrainMode : )
Description
trainf_ocr_class_svm
trains the OCR classifier
OCRHandle
with the training characters stored in the OCR
training files given by TrainingFile
. The training files
must have been created, e.g., using write_ocr_trainf
, before
calling trainf_ocr_class_svm
. The parameters
Epsilon
and TrainMode
have the same meaning as in
train_class_svm
. Please, note that training characters that have
no corresponding class in the classifier OCRHandle
are discarded.
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
OCRHandle
(input_control, state is modified) ocr_svm →
(handle)
Handle of the OCR classifier.
TrainingFile
(input_control) filename.read(-array) →
(string)
Names of the training files.
Default: 'ocr.trf'
File extension:
.trf
, .otr
Epsilon
(input_control) real →
(real)
Stop parameter for training.
Default: 0.001
Suggested values: 0.00001, 0.0001, 0.001, 0.01, 0.1
TrainMode
(input_control) number →
(string / integer)
Mode of training.
Default: 'default'
List of values: 'add_sv_to_train_set' , 'default'
Example (HDevelop)
* Train an OCR classifier read_ocr_trainf_names ('ocr.trf', CharacterNames, CharacterCount) create_ocr_class_svm (8, 10, 'constant', 'default', CharacterNames, \ 'rbf', 0.01, 0.01, 'one-versus-one', \ 'normalization', 81, OCRHandle) trainf_ocr_class_svm (OCRHandle, 'ocr.trf', 0.001, 'default') write_ocr_class_svm (OCRHandle, 'ocr.osc')
Result
If the parameters are valid the operator
trainf_ocr_class_svm
returns the value 2 (
H_MSG_TRUE)
. If necessary,
an exception is raised.
trainf_ocr_class_svm
may return the error 9211 (Matrix is
not positive definite) if Preprocessing
=
'canonical_variates' is used. This typically indicates
that not enough training samples have been stored for each class.
In this case we recommend to change Preprocessing
to
'normalization' . Another solution can be to add more
training samples.
Possible Predecessors
create_ocr_class_svm
,
write_ocr_trainf
,
append_ocr_trainf
,
write_ocr_trainf_image
Possible Successors
do_ocr_single_class_svm
,
do_ocr_multi_class_svm
,
write_ocr_class_svm
Alternatives
See also
Module
OCR/OCV