(PECL imagick 2 >= 2.3.0, PECL imagick 3)
Imagick::writeImageFile — Writes an image to a filehandle
$filehandle, string $format = ?): boolWrites the image sequence to an open filehandle. The handle must be opened with for example fopen. 此方法在Imagick基于ImageMagick 6.3.6以上版本编译时可用。
filehandleFilehandle where to write the image
成功时返回 true�