ImageMagick returns a status of 0 whenever a command or algorithm successfully complete without complaint. A warning code generally is typically just a notice that something unusual occurred but the command or algorithm still completed and most likely the results are still usable. An error means the command or algorithm could not complete as expected and any results are unreliable. A fatal error means the command or algorithm could not complete and the process exits prematurely and no results are returned.

ImageMagick Error and Warning Codes
Domain | Description | Warning | Error | Fatal Error
--- | --- | --- | --- | ---
Success | the command or algorithm completed successfully without complaint | 0 | 0 | 0
Resource Limit | a program resource is exhausted (e.g. not enough memory) | 300 | 400 | 700
Type | A font is unavailable; a substitution may have occurred | 305 | 405 | 705
Option | a command-line option was malformed | 310 | 410 | 710
Delegate | an ImageMagick delegate failed to complete | 315 | 415 | 715
Missing Delegate | the image type can not be read or written because the appropriate Delegate is missing | 320 | 420 | 720
Corrupt Image | the image file may be corrupt | 325 | 425 | 725
FileOpen | the image file could not be opened for reading or writing | 330 | 430 | 730
Blob | a binary large object could not be allocated, read, or written | 335 | 435 | 735
Stream | there was a problem reading or writing from a stream | 340 | 440 | 740
Cache | pixels could not be read or written to the pixel cache | 345 | 445 | 745
Coder | there was a problem with an image coder | 350 | 450 | 750
Module | there was a problem with an image module | 355 | 455 | 755
Draw | a drawing operation failed | 360 | 460 | 760
Image | the operation could not complete due to an incompatible image | 365 | 465 | 765
Wand | there was a problem specific to the MagickWand API | 370 | 470 | 770
Random | there is a problem generating a true or pseudo-random number | 375 | 475 | 775
XServer | an X resource is unavailable | 380 | 480 | 780
Monitor | there was a problem activating the progress monitor | 385 | 485 | 785
Registry | there was a problem getting or setting the registry | 390 | 490 | 790
Configure | there was a problem getting a configuration file | 395 | 495 | 795
Policy | a policy denies access to a delegate, coder, filter, path, or resource. | 399 | 499 | 799