S/N map of J1850-3147 at Hα after the process of HRSDI is shown. For visual inspection of the contrast curve derived from Eq. (3), three 5σ fake planets were injected at distances of 0.1′′, 0.3′′, and 0.5′′. All three fake planets are clearly visible. For display purposes, the image was smoothed with a Gaussian kernel of 2 pixels in radius. The magenta star indicates the star center.