def pixelsize(info_dict):
    """ Computes the pixel size in m/pixel
    Parameters
    -----------
    info_dict: dictionnary

    Returns
    -------
    pixelsize: float
               size of the pixel in meter/pixel
    """
    # Pixel length (m/pix)
    pixsize =  info_dict['cameras'][info_dict['channel']]['Photocell_SizeX'] * info_dict['binning_X']
    info_dict['pixelSize']=pixsize
    return info_dict