I have a folder of pdf files(~ 1600 images). I want to convert all .pdf images into .png images.
How can I do it?

**I tried**:

> 
> find . -maxdepth 1 -type f -name '\*.pdf' -exec pdftoppm -r 300 -png {}
> {} ;
> 
> 
> 

But have errors like:

```
Syntax Error: non-embedded font using identity encoding: Arial
Syntax Error: non-embedded font using identity encoding: Arial,Bold
Syntax Error: Can't get Fields array<0a>
Syntax Warning: Mismatch between font type and embedded font file
Syntax Error: Expected the optional content group list, but wasn't able to find it, or it isn't an Array

```

Is there any other solution for conversion?