PDF is not a raster image format; it is a special language for describing an image. To convert it to a raster format, you will need a RIP (raster image processor) .
ImageMagick uses GhsotScript for this. Therefore, you cannot do this with ImageMagick without GhostScript. You can use GhostScript to render PDF to JPG from the command line that starts gswin32.exe ( even without ImageMagic ), or from your software using gsdll32.dll.
You can also use the Adobe ActiveX component from your software. It is usually already installed on Windows with Adobe Acrobat.
Here is a good explanation and many ways to render PDF
valex
source share