Undefined im2uint8

Hello, I want use 'im2uint8' function but I have an error:

Answer 1

[Adam]

Whatever that code is is looking for a function called im2unit8, not im2uint8, which is a typo I also often make as my brain seems to autocorrect me typing uint to unit!

Just correct the code to use the correct function name and it should be fine assuming you have the Image Processing Toolbox

[Dani D]

Thank you for your reply, Now i have another problem.

[Adam]

There is no var2 function, at least not in my Matlab and I have the Statistics Toolbox.

You can use

var( img_rgb(:) )

but don't cast to 8-bit integer first as var does not support integers as the calculation needs to be done in floating point. If you need a uint8 final result than do the cast as the outer-most operation on the result of the rounded variance, not the input to var