how do i convert this string back to matrix of any size

i am having an rgb image matrix of 532*532 double after applying runlength encodng on rgb image .it has been converted to string of 1*45739..

how do i convert this string back to matrix of any size

[Stephen23]

Possibly something based on repelem and reshape would work, but without further details of how the string is defined/specified, it is hard to give more specific help.