  We have studied photon motion around axially symmetric rotating Kerr black
hole in the presence of plasma with radial power-law density. It is shown that
in the presence of plasma the observed shape and size of shadow changes
depending on i) plasma parameters, ii) black hole spin and iii) inclination
angle between observer plane and axis of rotation of black hole. In order to
extract pure effect of plasma influence on black hole image the particular case
of the Schwarzschild black hole has also been investigated and it has been
shown that i) the photon sphere around the spherical symmetric black hole is
left unchanged under the plasma influence, ii) however the Schwarzschild black
hole shadow size in plasma is reduced due to the refraction of the
electromagnetic radiation in plasma environment of black hole. The study of the
energy emission from the black hole in plasma shows that in the presence of
plasma the maximal energy emission rate from the black hole decreases.
