imagesc2( varargin )

% enhanced imagesc function with key control for colormap limit
% Parameters are given as you give to imagesc built-in function
%
% When plotted, you could use following keys to control your color limit
% 1. left arrow <-- and right arrow --> are for decreasing and increasing color
% limit range
% 2. upper arrow and down arrow are for increasing and decreasing upper limit
% of color
% 3. pageup and page down keys are for increasing and decreasing lower limit of
% color
% 4. key s is for set color limit manually
% 5. key r is for reset color limit to the default ([max(data),min(data)])
% 6. key f is for set changing factor every time you change you color limit
% Note: f could be a complex number and real part stand for multiplication
% and imaginary part stand for addition.