BPT classification in NGC 6946. Top panel: Map of the BPT classification, color-coded as indicated in the label. Bottom panel: BPT diagram for the individual fibers with SF-like spectra (blue symbols), Composite (green symbols), and AGN-like (red symbols). The black solid and red dashed curves are the demarcation lines between SF and AGN regions defined by Kauffmann et al. (2003) and Kewley et al. (2001), respectively. The ellipses in the top panel indicate the H I holes (see Sect. 4.2), while the small black circles denote regions dominated by DIG.