Quadtree decomposition (Encoding) and Decoding of RGB Image: avg=avgofmatblks(mat,i,j,w,h) - File Exchange

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Highlights from
Quadtree decomposition (Encoding) and Decoding of RGB Image

A =padtomakepowof2(A,varargin... % if required then add padvalue (defualt 0)
I=qtreedecode(S,values) % Decode QuadTree Represenation of Image given as Sparse matrix 'S' and
I=qtreergbdecode(S,valRGB) % Decode QuadTree date that is decomposed (encode) by qt3ddecom method
S=trimsparse(S) % trim sparse matrix by removing extra rows/columns that have all elements zeros.
[S,keys]=delsparsekeybyxANDy(...
[S,valRGB]=qt3ddecom(I,vararg... % This method uses three thresholds for red,green and blue blocks.
[b1r,b1c,b2r,b2c,b3r,b3c,b4r,... % The method uses three thresholds for red,green and blue blocks.
[b1r,b1c,b2r,b2c,b3r,b3c,b4r,... % given the size of rectangle (matrix end points), it split into four
avg=avgofmatblks(mat,i,j,w,h) % finds average of different blocks of input matrix
drawquadblocks(S) % draw square quad blocks of quadtree in eight basic colors.
fillrect_ulwh(ul,w,h,varargin... % fill the rectangle region specified by upper left corner width
flag=ispowerof2(n)
rgbimgnew =padrgbtomakepowof2... % if required then add padvalue (defualt 0)
var=converttoclass(var,type)
main.m
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from Quadtree decomposition (Encoding) and Decoding of RGB Image by Dr. Murtaza Khan
Quadtree decomposition (Encoding) and Decoding of RGB Image of size M-by-N-by-3.

avg=avgofmatblks(mat,i,j,w,h)

% % finds average of different blocks of input matrix
% % INPUT
% % i,j,w,h are vectors
% % mat : input matrix
% % i(k): beginning row index of kth block
% % j(k): beginning column index of kth block
% % w(k): width of kth block   (e.g. column 1 to colum 5 of mat)
% % h(k): height of kth block  (e.g. row 1 to row 3 of mat)
% % OUTPUT
% % avg(k): average of kth block (avg is a vector)
function avg=avgofmatblks(mat,i,j,w,h)

blkcount=length(i);
for k=1:blkcount        
    fromRow=i(k);
    toRow=i(k)+h(k)-1;
    fromCol=j(k);
    toCol=j(k)+w(k)-1;
    count=(toRow-fromRow+1).*(toCol-fromCol+1);
    avg(k)=sum(sum(mat(fromRow:toRow,fromCol:toCol)))/count; %avg/mean of block values
end

% % % --------------------------------
% % % Author: Dr. Murtaza Khan
% % % Email : drkhanmurtaza@gmail.com
% % % --------------------------------

Highlights from Quadtree decomposition (Encoding) and Decoding of RGB Image

Highlights from
Quadtree decomposition (Encoding) and Decoding of RGB Image