Why the output quality of the converted file is bad?

The program can recognize and convert normal PDF files especially for word-only ones well. If the output quality of the converted file is not so good, there are many factors:

1) The original PDF file is too complex and contain many elements such as pictures, graphs and so on.
2) The original PDF file is too blurry.
3) The color of the words is similar to the background in the original PDF file.

For scanned PDF files, it is because the OCR technique depends on the color and contrast of the original PDF files. If the color and contrast is not strong, it will affect the identification of OCR.

Please try different PDF files for more tests. Meanwhile, we are keeping optimizing the program and will release new versions periodically.