Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Try -gaussian-blur 0x3 (or faster -blur 0x3). But no guarantees. You may have to just try different values. We have no idea how GIMP does their Gaussian blur.