Skip to content

write_ocr_trainfWriteOcrTrainfWriteOcrTrainfwrite_ocr_trainfwrite_ocr_trainf🔗

Short description🔗

write_ocr_trainfWriteOcrTrainfWriteOcrTrainfwrite_ocr_trainfwrite_ocr_trainf — Storing of training characters into a file.

Signature🔗

write_ocr_trainf( region Character, image Image, string Class, filename.write TrainingFile )void WriteOcrTrainf( const HObject& Character, const HObject& Image, const HTuple& Class, const HTuple& TrainingFile )static void HOperatorSet.WriteOcrTrainf( HObject character, HObject image, HTuple classVal, HTuple trainingFile )def write_ocr_trainf( character: HObject, image: HObject, class_val: MaybeSequence[str], training_file: str ) -> None

Herror write_ocr_trainf( const Hobject Character, const Hobject Image, const char* Class, const char* TrainingFile )

Herror T_write_ocr_trainf( const Hobject Character, const Hobject Image, const Htuple Class, const Htuple TrainingFile )

void HRegion::WriteOcrTrainf( const HImage& Image, const HTuple& Class, const HString& TrainingFile ) const

void HRegion::WriteOcrTrainf( const HImage& Image, const HString& Class, const HString& TrainingFile ) const

void HRegion::WriteOcrTrainf( const HImage& Image, const char* Class, const char* TrainingFile ) const

void HRegion::WriteOcrTrainf( const HImage& Image, const wchar_t* Class, const wchar_t* TrainingFile ) const (Windows only)

void HRegion.WriteOcrTrainf( HImage image, HTuple classVal, string trainingFile )

void HRegion.WriteOcrTrainf( HImage image, string classVal, string trainingFile )

Description🔗

The operator write_ocr_trainfWriteOcrTrainf serves to prepare the training with the operator trainf_ocr_class_mlpTrainfOcrClassMlp or trainf_ocr_class_svmTrainfOcrClassSvm. Hereby regions, representing characters, including their gray values (region and pixel) and the corresponding class name will be written into a file. An arbitrary number of regions within one image is supported. For each character (region) in Charactercharactercharacter the corresponding class name must be specified in ClassclassValclass. The gray values are passed via the parameter Imageimageimage. If no file extension is specified in TrainingFiletrainingFiletraining_file the extension ‘.trf’ is appended to the file name. The version of the file format used for writing data can be defined by the parameter 'ocr_trainf_version'"ocr_trainf_version" of the operator set_systemSetSystem.

Execution information🔗

Execution information
  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).

  • Multithreading scope: global (may be called from any thread).

  • Processed without parallelization.

Parameters🔗

Charactercharactercharacter (input_object) region(-array) → objectHObjectHRegionHObjectHobject

Characters to be trained.

Imageimageimage (input_object) singlechannelimage → object (byte / uint2)HObject (byte / uint2)HImage (byte / uint2)HObject (byte / uint2)Hobject (byte / uint2)

Gray values of the characters.

ClassclassValclass (input_control) string(-array) → (string)HTuple (HString)HTuple (string)MaybeSequence[str]Htuple (char*)

Class (name) of the characters.

TrainingFiletrainingFiletraining_file (input_control) filename.write → (string)HTuple (HString)HTuple (string)strHtuple (char*)

Name of the training file.

Default: 'train_ocr'"train_ocr"
File extension: .trf

Example🔗

(C)

char       name[128]\;
HTuple     Class,Name\;

read_image(&Image,"character.tiff")\;
binary_threshold(Image,&Dark, 'otsu', 'dark', &UsedThreshold)\;
connection(Dark,&Character)\;
count_obj(Character,&num)\;
create_tuple(&Class,num)\;
open_window(0,0,-1,-1,0,"","",&WindowHandle)\;
set_color(WindowHandle,"red")\;
for (i=0\; i<num\; i++) {
  select_obj(Character,&SingleCharacter,i)\;
  disp_region(SingleCharacter,WindowHandle)\;
  printf("class of character %d ?\n",i)\;
  scanf("%s\n",name)\;
  set_s(Class,name,i)\;
}
create_tuple(&Name,1)\;
set_s(Class,Name,"trainfile")\;
T_write_ocr_trainf(Character,Image,Class,Name)\;

Result🔗

If the parameters are correct, the operator write_ocr_trainfWriteOcrTrainf returns the value 2 (H_MSG_TRUE). Otherwise an exception will be raised.

Combinations with other operators🔗

Combinations

Possible predecessors

thresholdThreshold, connectionConnection, read_ocr_trainfReadOcrTrainf

Possible successors

trainf_ocr_class_mlpTrainfOcrClassMlp, trainf_ocr_class_svmTrainfOcrClassSvm

Module🔗

OCR/OCV