AEM Assets PDF thumbnail cannot be generated correctly

[磊杨66044351]

I uploaded a pdf file to assets, but the thumbnail image can not be generated correctly.

The original pdf thumbnail image is as follows:

the thumbnail image in AEM Assets is as follows:

And I've tried the link: https://helpx.adobe.com/experience-manager/6-2/assets/using/aem-pdf-rasterizer.html

It doesn't work.

Thanks!

[磊杨66044351]

The PDF file download link: https://pan.baidu.com/s/1igxZZ2XkQ5aUGOTA4DuvxQ