There is no decode delegate for this `PNG 'ImageMagick CentOS image format

I am trying to use ImageMagick on CentOS to create PDF documents and convert PNG images. ImageMagic is already installed and the imaginary extension is loaded and working in PHP 5.5, but when I try to generate PDF or convert images, I get the following error: No decode delegate for this `PNG 'image format

I've already installed libpng and reinstalled ImageMagic, but the problem continues.