I am working information reading from Identity Card information using Tesseract Library.I got Confidence score of each word or each line.
Box[0]: x=13, y=12, w=1134, h=57, confidence: 40, text: REPUYBLIQUE FRANCAISE
Box[1]: x=21, y=75, w=1119, h=50, confidence: 42, text: 7 NN99 3W F 59W
Box[2]: x=17, y=137, w=539, h=52, confidence: 30, text: V7 7 D5 NOM1BOHEL
Box[3]: x=6, y=189, w=954, h=46, confidence: 0, text:
Box[4]: x=12, y=239, w=1016, h=34, confidence: 40, text: 5 Q HV2 H CHRISTIANL NICBLE HBNIOIJE
Box[5]: x=21, y=310, w=975, h=53, confidence: 67, text: 2 E 20 06 1329
Box[6]: x=28, y=372, w=1043, h=83, confidence: 0, text:
Box[7]: x=11, y=397, w=1147, h=67, confidence: 0, text:
Box[8]: x=251, y=461, w=837, h=46, confidence: 0, text:
Box[9]: x=157, y=475, w=1019, h=105, confidence: 0, text:
Box[10]: x=59, y=648, w=1045, h=32, confidence: 81, text: IDFRADOUEL<<<<<<<<<<<<<<<<<<<<932013
Box[11]: x=57, y=722, w=1047, h=34, confidence: 76, text: 0506932020438CHRISTIANE<<NI2906209F3
Here is code used.
Pix *image = pixRead("/usr/src/tesseract-3.02/phototest.tif");
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
api->Init(NULL, "eng");
api->SetImage(image);
Boxa* boxes = api->GetComponentImages(tesseract::RIL_TEXTLINE, true, NULL, NULL);
printf("Found %d textline image components.\n", boxes->n);
for (int i = 0; i < boxes->n; i++) {
BOX* box = boxaGetBox(boxes, i, L_CLONE);
api->SetRectangle(box->x, box->y, box->w, box->h);
char* ocrResult = api->GetUTF8Text();
int conf = api->MeanTextConf();
fprintf(stdout, "Box[%d]: x=%d, y=%d, w=%d, h=%d, confidence: %d, text: %s",
i, box->x, box->y, box->w, box->h, conf, ocrResult);
}
Now i need to read all the words from Identity card.But i set the value tesseract::RIL_TEXTLINE as tesseract::RIL_WORD and ran the code. I got high confidence value even words there not in image.
1.Is confidence score used to read information from Identity card.?
1.What is actually confidence score returned from tesseract OCR.?