Energy-coded X-ray image of the W28 complex with FXT (a), consisting of bands in 0.4-0.7 keV (red), 0.7-1.1 keV (green), and 1.12.3 keV (blue). The single-band images of each energy band are shown in panels (b), (c), and (d). The images are in units of count s⁻¹ cm⁻² and in a square-root color scale to enhance weak emissions. All the images are vignetting-corrected and adaptively smoothed. The structures mentioned in this paper are marked in panels (c) and (d). The cyan regions correspond to optical and/or radio SNR candidates (Stupar & Parker 2011; Stupar et al. 2018).