编译下面的程序操作系统必须在安装了tesseract库和leptonica库才可以
Basic example
c++ code:
#include <tesseract/baseapi.h>
#include <leptonica/allheaders.h>
int main()
{
char *outText;
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
// Initialize tesseract-ocr with English, without specifying tessdata path
if (api->Init(NULL, "eng")) {
fprintf(stderr, "Could not initialize tesseract.
");
exit(1);
}
// Open input image with leptonica library
Pix *image = pixRead("/usr/src/tesseract-3.02/phototest.tif");
api->SetImage(image);
// Get OCR result
outText = api->GetUTF8Text();
printf("OCR output:
%s", outText);
// Destroy used object and release memory
api->End();
delete [] outText;
pixDestroy(&image);
return 0;
}
GetComponentImages example
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.
", 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);
}
Result iterator example
There is posibility to get confidence value and BoundingBox per word from ResultIterator:
Pix *image = pixRead("/usr/src/tesseract-3.02/phototest.tif");
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
api->Init(NULL, "eng");
api->SetImage(image);
api->Recognize(0);
tesseract::ResultIterator* ri = api->GetIterator();
tesseract::PageIteratorLevel level = tesseract::RIL_WORD;
if (ri != 0) {
do {
const char* word = ri->GetUTF8Text(level);
float conf = ri->Confidence(level);
int x1, y1, x2, y2;
ri->BoundingBox(level, &x1, &y1, &x2, &y2);
printf("word: '%s'; conf: %.2f; BoundingBox: %d,%d,%d,%d;
",
word, conf, x1, y1, x2, y2);
delete[] word;
} while (ri->Next(level));
}
Orientation and script detection (OSD) example
const char* inputfile = "/usr/src/tesseract-3.02/eurotext.tif";
tesseract::Orientation orientation;
tesseract::WritingDirection direction;
tesseract::TextlineOrder order;
float deskew_angle;
PIX *image = pixRead(inputfile);
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
api->Init("/usr/src/tesseract-3.02/", "eng");
api->SetPageSegMode(tesseract::PSM_AUTO_OSD);
api->SetImage(image);
api->Recognize(0);
tesseract::PageIterator* it = api->AnalyseLayout();
it->Orientation(&orientation, &direction, &order, &deskew_angle);
printf("Orientation: %d; WritingDirection: %d TextlineOrder: %d "
"Deskew angle: %.4f ",
orientation, direction, order, deskew_angle);
Example of iterator over the classifier choices for a single symbol
Pix *image = pixRead("/usr/src/tesseract-3.02/phototest.tif");
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
api->Init(NULL, "eng");
api->SetImage(image);
api->SetVariable("save_blob_choices", "T");
api->SetRectangle(37, 228, 548, 31);
api->Recognize(NULL);
tesseract::ResultIterator* ri = api->GetIterator();
tesseract::PageIteratorLevel level = tesseract::RIL_SYMBOL;
if(ri != 0) {
do {
const char* symbol = ri->GetUTF8Text(level);
float conf = ri->Confidence(level);
if(symbol != 0) {
printf("symbol %s, conf: %f", symbol, conf);
bool indent = false;
tesseract::ChoiceIterator ci(*ri);
do {
if (indent) printf(" ");
printf(" - ");
const char* choice = ci.GetUTF8Text();
printf("%s conf: %f ", choice, ci.Confidence());
indent = true;
} while(ci.Next());
}
printf("--------------------------------------------- ");
delete[] symbol;
} while((ri->Next(level)));
}
在linux下面编译C++ 程序的方法：
g++ -o myprogram myprogram.cpp -llept -ltesseract
如果你安装tesssract的时候不是通常的路径，需要手动指定头文件的include和库lib的路径。加上选项-I和-L如：
g++ -o myprogram myprogram.cpp -I/home/nick/local/include/tesseract -L/home/nick/local/lib -llept -ltesseract
c语言程序的例子：
#include <stdio.h>
#include <allheaders.h>
#include <capi.h>
void die(const char *errstr) {
fputs(errstr, stderr);
exit(1);
}
int main(int argc, char *argv[]) {
TessBaseAPI *handle;
PIX *img;
char *text;
if((img = pixRead("img.png")) == NULL)
die("Error reading image
");
handle = TessBaseAPICreate();
if(TessBaseAPIInit3(handle, NULL, "eng") != 0)
die("Error initialising tesseract
");
TessBaseAPISetImage2(handle, img);
if(TessBaseAPIRecognize(handle, NULL) != 0)
die("Error in Tesseract recognition
");
if((text = TessBaseAPIGetUTF8Text(handle)) == NULL)
die("Error getting text
");
fputs(text, stdout);
TessDeleteText(text);
TessBaseAPIEnd(handle);
TessBaseAPIDelete(handle);
pixDestroy(&img);
return 0;
}
在linux下面编译C语言程序的方法和c++的方法是一样的，只不过换个编译器就好：
gcc -o myprogram myprogram.cpp -llept -ltesseract
如果你安装tesssract的时候不是通常的路径，需要手动指定头文件的include和库lib的路径。加上选项-I和-L如：
gcc -o myprogram myprogram.cpp -I/home/nick/local/include/tesseract -L/home/nick/local/lib -llept -ltesseract
运行方法：
把一个图片复制到当前目录下命名为 img.png
./myprogram img.png