(PECL gmagick >= Unknown)
Gmagick::writeimage — Writes an image to the specified filename
Writes an image to the specified filename. If the filename parameter is NULL, the image is written to the filename set by Gmagick::ReadImage() or Gmagick::SetImageFilename().
filename
The image filename.
The Gmagick object
����ʱ�׳� GmagickException��