Using the 'dfm graph' command, you can also get the graph images shown in Ops Manager UI.
dfm graph [<options>] <graph-name> <name-or-id-to-graph>
The options are
-s <start-date>
-e <end-date>
-D <date-format>
-F <output-format>
The <output-format> is the type of format in which the output will be generated. Supported output formats are text, html, csv, xls, png and gif.
The output for html, png and gif is in binary format and needs to be redirected to a file with proper extension to open it.
For example, to see the output of the graph 'volume-usage'
in gif format, issue the command like below
$ dfm graph -F gif volume-usage > graph.gif