[Bug]: (possibly a feature request) error: read_params_file: Can't open hocr AND read_params_file: Can't open txt

[clach04]

What were you trying to do?

Trying to use "best" English Tesseract data and OCRmyPDF completely fails. Issue unrelated to input; this is about dependency on Tesseract scripts.

This is due to the use of "hocr" and "txt" script parameters into tesseract.

I downloaded https://github.com/tesseract-ocr/tessdata_best eng.traineddata and set TESSDATA_PREFIX to point at that directory (as most tesseract installs only include fast)... but that directory did not contain:

• configs/hocr
• configs/txt

Providing those avoids this problem completely :-)

One of the really great things about OCRmyPDF is that will print out suggestions when things are missing (like Ghostscript).

Ideas:

1. add logic to check for these errors and emit useful information
2. add a note to https://ocrmypdf.readthedocs.io/en/latest/errors.html
3. document the Tesseract scripts requirement in the installation docs

It took me a while to debug this, hence opening up the issue for discussion. What made this tricky (for me, as a person new to OCRmyPDF) was the missing errors from Tesseract.

Semi-related:

• [Feature]: more detailed information for: lots of diacritics - possibly poor OCR #1566

Thanks for such a useful tool!

Where are you installing/running from?

Wndows package manager (chocolatey, etc.)

OCRmyPDF version

16.10.4

What operating system are you working on?

Windows

Operating system details and version

Windows 11 - Microsoft Windows [Version 10.0.22631.5624]

Simple sanity checks

• Operating system is currently supported by its vendor (not end of life)
• Python version is compatible with OCRmyPDF
• This issue is not about a specific input file

Relevant log output

Scanning contents     ---------------------------------------- 100% 88/88 0:00:00
Start processing 16 pages concurrently                                                                                                                                            ocr.py:96
    2 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257
    2 [tesseract] read_params_file: Can't open txt                                                                                                                         tesseract.py:257
    7 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257
    7 [tesseract] read_params_file: Can't open txt                                                                                                                         tesseract.py:257
    3 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257
    3 [tesseract] read_params_file: Can't open txt                                                                                                                         tesseract.py:257
   14 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257
   14 [tesseract] read_params_file: Can't open txt                                                                                                                         tesseract.py:257
    1 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257
    1 [tesseract] read_params_file: Can't open txt                                                                                                                         tesseract.py:257
    5 [tesseract] read_params_file: Can't open hocr                                                                                                                        tesseract.py:257


with an eventual stack trace and failure.