This code divides an image into foreground and background . After that i calculated the threshold value, and varVariance. It gives an error at If varVlues> Th , Cell contents reference from a non-cell array object."

rgbImage = imread('cameraman.tif');

[r,c]=size(rgbImage);

w = size(rgbImage,1);

h = size(rgbImage,2);

imshow(rgbImage);

set(gcf, 'units','normalized','outerposition',[0 0 1 1]);

drawnow;

[rows columns numberOfColorBands] = size(rgbImage);

blockSizeR = 40; % Rows in block.

blockSizeC = 40; % Columns in block.

wholeBlockRows = floor(rows / blockSizeR);

blockVectorR = [blockSizeR * ones(1, wholeBlockRows), rem(rows, blockSizeR)];

wholeBlockCols = floor(columns / blockSizeC);

blockVectorC = [blockSizeC * ones(1, wholeBlockCols), rem(columns, blockSizeC)];

if numberOfColorBands > 1

ca = mat2cell(rgbImage, blockVectorR, blockVectorC, numberOfColorBands);

else

ca = mat2cell(rgbImage, blockVectorR, blockVectorC);

end

plotIndex = 1;

numPlotsR = size(ca, 1);

numPlotsC = size(ca, 2);

for r = 1 : numPlotsR

for c = 1 : numPlotsC

fprintf('plotindex = %d, c=%d, r=%d\n', plotIndex, c, r);

subplot(numPlotsR, numPlotsC, plotIndex);

rgbBlock = ca{r,c};

imshow(rgbBlock); % Could call imshow(ca{r,c}) if you wanted to.

[rowsB columnsB numberOfColorBandsB] = size(rgbBlock);

drawnow;

plotIndex = plotIndex + 1; end end

meanValues = cellfun(@(x) mean(x(:)),ca);

varValues = cellfun(@(x) var(double(x(:))),ca);

       for i=1:numPlotsC+2

            varValues1(1,i)=0;    
            varValues1(numPlotsR+2,i)=0;

        end
        for i=2 : numPlotsR+2

            varValues1(i,1)=0;    
            varValues1(i,numPlotsC+2)=0;

        end

              for i=1:numPlotsR
                for j=1:numPlotsC  
                varValues1(i+1,j+1)=varValues(i,j);

                end

              end  

    for k = 1 : numPlotsR
    for l = 1 : numPlotsC          %#ok<ALIGN>
        VGx(k,l)=(varValues1(k+2,l+1)-varValues1(k,l+1))/2;

        VGy(k,l)=(varValues1(k+1,l+2)-varValues1(k+1,l))/2;
        mag(k,l)=sqrt((VGx(k,l).^2)+(VGy(k,l).^2));

s1=.32; s2=.68;

% double LT(k,l);

LT(k,l)=s1*mag(k,l)+s2*varValues(k,l);

Th(k,l)=sqrt(LT(k,l))/meanValues(k,l);

end

    end

   for i=1:11
       for j=1:numPlotsC

    if varValues>=Th

        ca=varValues(i,j);

    end   

    combine = cell2mat(ca);

       end

   end  

    figure,imshow(combine);

[Sheshjee]

please help me to suggest me why i am getting this error "Cell contents reference from a non-cell array object."

Answer 1

[Image Analyst]

Well the top part looks like my example, but then you did some stuff after that which I don't understand. Originally, ca was a cell array. But you actually redefine ca like this:

ca=varValues(i,j);

for some reason. So now ca is simply a scalar double number, not a cell array anymore. But then immediately afterwards you do this:

combine = cell2mat(ca);

which assumes ca is a cell array. But it's not because you redefined it, so that's why you get the error. But that's about as far as I went because there were no comments to explain what you were doing. All I know is that whatever you're doing, you're doing it incorrectly.