can anyone help in extracing(destego) the original image from the stegoimage for the stego function code is given below

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SWAGATIKA DEVI 2018-4-17

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https://ww2.mathworks.cn/matlabcentral/answers/395445-can-anyone-help-in-extracing-destego-the-original-image-from-the-stegoimage-for-the-stego-functio

function stegoImage = stego(grayCoverImage,hiddenString,integerValue)

[grayCoverImage, storedColorMap] = imread(grayCoverImage); [rows, columns, numberOfColorChannels] = size(grayCoverImage); if numberOfColorChannels > 1 grayCoverImage = grayCoverImage(:, :, 2); elseif ~isempty(storedColorMap) grayCoverImage = ind2rgb(grayCoverImage, storedColorMap); grayCoverImage = uint8(255 * mat2gray(rgb2gray(grayCoverImage))); end [rows, columns, numberOfColorChannels] = size(grayCoverImage);

hFig = figure; subplot(1, 2, 1); imshow(grayCoverImage, []); axis on; caption = sprintf('original Image.'); title(caption); set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]); %integerValue = round(str2double(cell2mat(1))); if isnan(integerValue) integerValue = defaultValue; end bitToSet = integerValue; if bitToSet < 1 bitToSet = 1; elseif bitToSet > 8 bitToSet = 8; end %hiddenString = sprintf('%4.4d%s', length(hiddenString), hiddenString) asciiValues = hiddenString - 0; stringLength = length(asciiValues); numPixelsInImage = numel(grayCoverImage); bitsPerLetter = 7; numPixelsNeededForString = stringLength * bitsPerLetter; if numPixelsNeededForString > numPixelsInImage asciiValues = asciiValues(1:floor(numPixelsInImage/bitsPerLetter)); stringLength = length(asciiValues); numPixelsNeededForString = stringLength * bitsPerLetter; else message = sprintf('Your message is %d characters long.\nThis will require %d * %d = %d pixels,\nYour image has %d pixels so it will fit.',... stringLength, stringLength, bitsPerLetter, numPixelsNeededForString, numPixelsInImage); fprintf('%s\n', message); end binaryAsciiString = dec2bin(asciiValues)' whos binaryAsciiString binaryAsciiString = binaryAsciiString(:)' stegoImage = grayCoverImage; stegoImage(1:numPixelsNeededForString) = bitset(stegoImage(1:numPixelsNeededForString), bitToSet, 0); oneIndexes = find(binaryAsciiString == '1'); stegoImage(oneIndexes) = bitset(stegoImage(oneIndexes), bitToSet, 1); subplot(1, 2, 2); imshow(stegoImage, []); axis on; caption = sprintf('stego Image.'); title(caption); end