Swap a logo on a halftone-textured image by period-shift cloning

To replace a logo on a textured stamp/badge PNG without an inpainting model: erode the dark-pixel mask with a MinFilter (~7px) so the small halftone dots vanish and only the logo survives, giving a clean bbox. Measure the dot pitch by autocorrelating the row-sum profile of a logo-free region, then paste a band of texture from above the logo shifted down by an exact multiple of that pitch (e.g. 16 x 10px); the grid lines up and the patch is invisible. For the new logo, render the SVG with headless Chrome (--headless=new --default-background-color=00000000 --window-size=W,H --screenshot) when cairosvg/rsvg are missing; PIL alpha_composite handles the rest. Recolor an SVG for a single-ink version with sed on fill= attributes.