On the fly field formatting in kibana 4.1

Is there any way in current version of kibana (or in any upcomimg releases) to format a field value from integer to string on the fly.
Something like :

My documents in Elastcsearch :
{"OperatingSystem":1}
{"OperatingSystem":2}
{"OperatingSystem":3}

Expecting documents in kibana :
{"OperatingSystem":"Windows7"}
{"OperatingSystem":"Windows8"}
{"OperatingSystem":"Windows10"}

I need some sort of mapping in kibana-
1 => Windows7
2 => Windows8
3 => Windows10

*I dont want to change field values in logstash.
*Need to keep index as small as possible.

Thanks in advanced.
Any hint would be appreciated.

Ankur Mathur

Not currently, but we're tracking an enhancement in this regard. Feel free to comment or +1. Btw, it's marked as "adoptme", which means that we'd love to see this as a community contribution!

Thanks for the info.
It would be an excellent enhancement.