#304 bug(ddjvu): -mode=black doesn't preserve all symbols

[Саша_Черных]

1. Summary

If I use -mode=black, some symbols not preserve.

2. Data

For example, I have 2 djvu files — Kira1.djvu and Kira491.djvu (see attachments):

• Kira1.djvu

• Kira491.djvu:

3. Steps to reproduce

ddjvu -format=pdf -mode=black Kira1.djvu Kira1.pdf

ddjvu -format=pdf -mode=black Kira491.djvu Kira491.pdf

4. Expected behavior

Correct displaying all symbols.

5. Actual behavior

Compare Kira1.pdf and Kira491.pdf from attachments with source DjVu files:

• Kira1.pdf:

• Kira491.pdf:

6. Not helped

Options:

• -quality=uncompressed
• -quality=150

I have the same result.

7. Note

Source DjVu not my personal scans, it from third-party scanned of old Soviet books. I have solely DjVu for further processing.

8. Environment

• Windows 10 Enterprise LTSB 64-bit EN
• DjVuLibre-3.5.27_DjView-4.11

Thanks.