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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def loggray(x, a, b):
 """Auxiliary function that specifies the logarithmic gray scale. a and b are the cutoffs."""

    linval = 10.0 + 990.0 * (x-float(a))/(b-a)
    return (np.log10(linval)-1.0)*0.5 * 255.0