how can change the value of one bit in a pixcel

imatlab every pixcel save as decimal i want to cchange the value of 1 bit for example if the value of pixcel is 2 i chnged it to binary it is 00000010 i want if its 7 bit is 0 it change to 1 and its 7 bit is 1 it change to 0

Answer 1

[Azzi Abdelmalek]

a='00000010',
a(7)=num2str(not(str2num(a(7))))

Answer 2

[Image Analyst]

Look at this snippet from my attached watermarking demo:

% Set the bit of originalImage(a copy, actually) to the value of the watermark.
watermarkedImage = originalImage; % Initialize
for column = 1 : visibleColumns
  for row = 1 : visibleRows
    watermarkedImage(row, column) = bitset(originalImage(row, column), bitToSet, watermark(row, column));
  end
end

See how it takes the original pixel, originalImage(row, column), and sets bit number "bitToSet" to a 0 or 1 value, watermark(row, column)

In its simplest form

outputPixelValue = bitset(originalPixelValue, bitToSet, desiredBitSetting);