Hi friends.
 I'm Chinese. Well, my English isn't very good。
 I'm using ghostscript for PDF to image(PNG).
 When I used cidfmap to map some simplified Chinese fonts (Founder fonts), I encountered some problems and a small number of punctuation marks were lost（like 5·18 the ·is lost）.
 When I remove these mappings, will use the default font and the punctuation will work fine.
 This was strange, because the PDF documents were not generated locally by me, but by another application. 
 I tried other methods, such as using Microsoft Office Word to edit text and punctuation in the same font, such as "·" and then converting to PDF, and then using the ghoscript command to convert.
 Of course, I also used Adobe Acrobat DC to try to convert problematic PDF to PNG, it correctly recognized and converted these fonts and punctuation marks.

 
 command:gswin64c -dBATCH -dFAPIDEBUG -dNOPAUSE  -sDEVICE=pngalpha -sOutputFile=f:/test%03d.png f:/test.pdf