i wrote a function in MATLAB which will divide a audio waveform (a speech) into smaller windows with overlap .The output will be a matrix X, each column of which contains the windows which i export. Then i calculate the FFT of each column, i remove half of fft bins and i visualize the measure of each FFT frame as an image, using the "imagesc" command.Then i made a spectrogram of my signal and it gives me this figure. Im wondering if this two figures are the same or not. Ok it seems that maybe they are the same but why the colors for example are different? Or is there any other difference between this two figures?