Translating From Chinese to English feature isn't working 90% of the time #1176

Before you asking

• I have tried the PDFMathTranslate-next and give feedback in PDFMathTranslate-next
• I have searched the existing issues
• I spend at least 5 minutes for thinking and preparing
• I have thoroughly and completely read the wiki.
• I have carefully checked the issue, and it is unrelated to the network environment.

Environment

- **OS** : Windows11
 - Python : Python 3.12.6
 - **pdf2zh**: pdf2zh-version-win64 v1.9.11

How to install pdf2zh

exe

Describe the bug

I am trying to use the feature of translating the Chinese documents into English so that I can work more efficiently instead of translating each page one by one. However, even after testing with multiple PDF and Chinese research papers, it simply doesn't work.

Sometimes it just doesn't translate ANYTHING AT ALL, it can't detect the Chinese Characters at all.
Sometimes it translates the PDF, and just overlays the translated text over the Chinese text.
AND RARELY does it ever work (only works when translating English/French to Chinese, that's where it shines...).

Screenshot 1 : tried to translate this Chinese research paper into English, failed dramatically:
(source of Chinese paper pdf : https://files.sciengine.com/pdfs/2095-9389/339255C2A19041C38D68C67342C41571.pdf?attname=Research+progress+in+integrated+thermal+management+of+electric+vehicles.pdf)

Screenshot 2 : again, nothing being translated...

I did also have the need to translate excel sheets in Chinese (that were converted to PDFs, and it still didn't translate any Chinese characters.

Is this normal, is the tool really bad at translating Chinese characters to English ?

To Reproduce

Expected behavior

I expected to have a Chinese-based PDF translated nicely into English, just as shown in the examples given in the README.md

Relevant log output

Origin PDF file

Chinese EV research paper - 电动汽车集成热管理研究现状及展望.pdf

d6w3MCcy6zvBWw4Ad.pdf

Anything else?

No response