How to find variance,entropy,average gradient of an image?

[EDIT: Mon May 23 17:42:16 UTC 2011 - Removed Duplicates - MKF]

[EDIT: 20110523 13:03 CDT - clarify - WDR]

how to find variance, entropy, average gradient of an image?...my image is of class uint8...

Answer 1

[Sean de Wolski]

doc mean
doc var
doc gradient
doc entropy
doc double  %convert from uint8

[Aditi]

what does doc stand for

[Sean de Wolski]

Documentation. Type each of those lines at the command window and read the ensuing documentation.