C++ Tesseract OCR: Getting ObjectCache(): WARNING! LEAK! object still has count 1 - c++

Question

I installed libtesseract-dev (v4.1.1) on Ubuntu 20.04 & I am trying out a C++ code to OCR an image to searchable PDF.
My code is somewhat modified than the C++ API example code provided at official website:
/home/test/Desktop/Example2/testexample2.cpp:
#include <leptonica/allheaders.h>
#include <tesseract/baseapi.h>
#include <tesseract/renderer.h>
int main()
{
//const char* input_image = "/usr/src/tesseract-oc/testing/phototest.tif";
//const char* output_base = "my_first_tesseract_pdf";
//const char* datapath = "/Projects/OCR/tesseract/tessdata";
const char* input_image = "001.jpg";
const char* output_base = "001";
const char* datapath = ".";
int timeout_ms = 5000;
const char* retry_config = nullptr;
bool textonly = false;
int jpg_quality = 92;
tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
if (api->Init(datapath, "eng")) {
fprintf(stderr, "Could not initialize tesseract.\n");
exit(1);
}
/*
tesseract::TessPDFRenderer *renderer = new tesseract::TessPDFRenderer(
output_base, api->GetDatapath(), textonly, jpg_quality);
*/
tesseract::TessPDFRenderer *renderer = new tesseract::TessPDFRenderer(
output_base, api->GetDatapath(), textonly);
bool succeed = api->ProcessPages(input_image, retry_config, timeout_ms, renderer);
if (!succeed) {
fprintf(stderr, "Error during processing.\n");
return EXIT_FAILURE;
}
api->End();
return EXIT_SUCCESS;
}
I also followed https://stackoverflow.com/a/59382664 as follows:
cd /home/test/Desktop/Example2
wget https://github.com/tesseract-ocr/tessdata/raw/master/eng.traineddata
wget https://github.com/tesseract-ocr/tesseract/blob/master/tessdata/pdf.ttf
export TESSDATA_PREFIX=$(pwd)
gedit config
(In the config file, entered the contents:
tessedit_create_pdf 1 Write .pdf output file
tessedit_create txt 1 Write .txt output file
)
g++ testexample2.cpp -o testexample2 -ltesseract
./testexample2
But on execution, it displays the errors as follows:
Warning: Invalid resolution 0 dpi. Using 70 instead.
Error during processing.
ObjectCache(0x7f1b096669c0)::~ObjectCache(): WARNING! LEAK! object 0x55af5c5241a0 still has count 1 (id /home/test/Desktop/Example2/eng.traineddatapunc-dawg)
ObjectCache(0x7f1b096669c0)::~ObjectCache(): WARNING! LEAK! object 0x55af5c506770 still has count 1 (id /home/test/Desktop/Example2/eng.traineddataword-dawg)
ObjectCache(0x7f1b096669c0)::~ObjectCache(): WARNING! LEAK! object 0x55af5c9a4a70 still has count 1 (id /home/test/Desktop/Example2/eng.traineddatanumber-dawg)
ObjectCache(0x7f1b096669c0)::~ObjectCache(): WARNING! LEAK! object 0x55af5c9a4980 still has count 1 (id /home/test/Desktop/Example2/eng.traineddatabigram-dawg)
ObjectCache(0x7f1b096669c0)::~ObjectCache(): WARNING! LEAK! object 0x55af5d7d5170 still has count 1 (id /home/test/Desktop/Example2/eng.traineddatafreq-dawg)
My directory structure is:
Example2
|------->001.jpg
|------->config
|------->eng.traineddata
|------->pdf.ttf
|------->testexample2
|------->testexample2.cpp
I have searched about this on multiple sources, but could not find any fix for this.
Further, I would like to know if there is someway I can build a binary using C++ compilation from this code + libtesseract such that my binary becomes a standalone portable binary, running which on other Ubuntu systems would not require reinstalling tesseract libraries & their dependencies

Answer 1

tesseract API examples is show case for using tesseract features without covering all specifics of programming language of your choice (c++ in your case).
Just looking at your code even without trying it: you dynamically allocates memory 2x but you did not deallocate them. Try to fix these issues.

Answer 2

You must free use dynamic memory for your class "api"
Use:
... you code...
if (renderer) delete renderer;
if (api) delete api;