Histogram matching of two images in Python 2.x?

Question

I\'m trying to match the histograms of two images (in MATLAB this could be done using imhistmatch). Is there an equivalent function available from a standard Python library

Answer 1

I would like to add a minor addition to both the solution written above. If somebody plans to make this as a global function (such as for grayscale images), it would be a good idea to convert the final matched array into its corresponding format (numpy.uint8). This might help in future image conversions without creating conflicts.

def hist_norm(source, template):

    olddtype = source.dtype
    oldshape = source.shape
    source = source.ravel()
    template = template.ravel()

    s_values, bin_idx, s_counts = np.unique(source, return_inverse=True,
                                            return_counts=True)
    t_values, t_counts = np.unique(template, return_counts=True)
    s_quantiles = np.cumsum(s_counts).astype(np.float64)
    s_quantiles /= s_quantiles[-1]
    t_quantiles = np.cumsum(t_counts).astype(np.float64)
    t_quantiles /= t_quantiles[-1]
    interp_t_values = np.interp(s_quantiles, t_quantiles, t_values)
    interp_t_values = interp_t_values.astype(olddtype)

    return interp_t_values[bin_idx].reshape(oldshape)