Do you get any error messages if you print out the three $xes? (see Handling Exceptions)

Update: in particular, note that context (i.e. string/numeric) matters here. E.g.

$x = $image->Read(...);
warn "$x" if "$x";      # string context:  the error/warning message (
+if any)
print 0+$x;             # numeric context: the number of images read
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