K-corona maps calculated using the inversion (K_inv, left panel) and correlation (K_corr, mid panel) methods. K_inv is obtained using the pB image acquired on June 1, 2001 at 9:00 and B image on June 1, 2001 at 09:07 (as in Fig. 2). K_corr is calculated as the difference between the same total brightness image and the F_corr map obtained for June 2001. Right panel: relative difference between K_corr and K_inv. The horizontal axis corresponds to the polar angle ϕ in degrees, and the vertical axis is the heliocentric distance r in the R_⊙ units.