JPG to SVG

JPEG saves space by blurring detail into small blocks, and leaves faint halos where sharp edges meet. A tracer that copied every one of them would give you thousands of tiny shapes. Two settings deal with it: Remove specks drops patches smaller than the size you pick, and fewer Colours merge the halo’s in-between shades into the colours either side.

Start with the defaults, then raise Remove specks if the preview shows dots along the edges. For a heavily compressed JPG, 8 pixels or more is not unusual.

A JPG has no see-through pixels, so the white or coloured background behind a logo becomes a shape of its own in the SVG. That is fine for printing on white; to place the logo on a coloured page, delete the background shape in your vector editor, or start from a PNG with transparency if you have one.

Scanned line art is different: Drawing keeps only the dark lines, in black, and leaves the paper out entirely.

Photo turns a picture into flat areas of colour, a look between a poster and a paper cut-out. A photo is traced at up to 1 megapixel, so a phone picture is traced from a smaller copy; one traced at that size takes a second or two and makes an SVG of about 0.4 MB. The SVG still shows at the photo’s full size.

Fewer colours give a bolder, simpler image and a smaller file. More colours keep more of the shading, at the cost of a larger file.