# Logarithmic vs Nth root transformation of Image

This is an image for the explanation of Logarithmic Transformation of an Image. I want to ask considering a input pixel value rk, Value of nth root of rk should be greater than corresponding value of log(rk). But this image is not accordance with that?

Can someone explain ?

• Indeed. Plus, scaled powers $\frac{y^\lambda-1}{\lambda}$ tend to $\log$ as $\lambda\to 0$, hence the hierarchy $x, x^{1/n},\log$ Oct 13 '20 at 16:31