%% DCTmanny.m
% script to show block frequencies and histogram

% S. Allen Broughton 29 Oct 10

%% load picture
load mandrill
X =X(1:480,1:496); % divisible by 8
X = X-127;
dX = blkdct2(X,8,8);
figure(1)
imagesc(dX);
colormap(gray);
%% 
bdX = blkgroupfreqs(dX,8,8);
figure(2)
imagesc(bdX)
colormap(gray)
%% 
figure(3)
blkfreqhist(dX,8,8,0,0,20);