Working on an OCR project, I am trying to figure out if there is any way or possibility to omit Leptonica Library from Tesseract and maybe replace it with OpenCV. Already have OpenCV on the C layer and planning to combine that with Tesseract.
No, it is not possible (unless you rewrite tesseract).
But you can compile leptonica with the minimal dependencies (zlib + png).
Also I would suggest to check your OpenCV package as it includes support for tesseract OCR.