[poppler] About the conversion function (PDF=>JPEG) of pdftoppm

[勝村信夫]

Hi

Although the PDF file is changed into the JPEG file using pdftoppm, the case
which is not convertible in part has come out.
Then, please let me know about the following point.

pdftoppm version 0.16.7 How many are there any versions of a convertible PDF file?
How many are there any versions of a convertible PDF file in the newest pdftoppm?