error WriteBlob Failed using ImageMagick 6.7.9

Question

I want to create an image from a pdf file. I have installed ImageMagick on a Linux server and successfully created an image from a terminal with root access.

Command:

 /usr/local/bin/convert http://www.artisticancestry.com/sites/default/files/media/Getting%20Started_7.pdf /public_html/testing.png

But When i am going to execute this command from php exec() function. It is showing this type of error

error: convert: unable to open image /public_html/testing-0.png': No such file or directory @ error/blob.c/OpenBlob/2642. convert: WriteBlob Failed/public_html/testing-0.png' @ error/png.c/MagickPNGErrorHandler/1751.

There is some permission issue but don't know which file has no permission.How can I find out what is causing this problem and how can I solve it?

Answer 1

It was a permission issue for me

chmod -R 777 /dir

/dir = Directory where you want to writing your image