Turn a photo into a line drawing that still looks like the person

Canva, Photoshop's sketch filters and most free converters detect edges and threshold them. Fast, free, perfectly reproducible, and it works on anything including buildings and products. It also traces noise as though it were line work, so busy backgrounds turn to scribble and soft edges disappear entirely.

The model understands that it is looking at a face and decides which lines carry meaning. You get varied line weight, deliberate omission and clean whites. The trade is that it invents: a strand of hair may not be your strand of hair, and no two runs are identical.

If you want a faithful trace for a colouring page, cutting file or technical use, take the filter. If you want something that looks hand-drawn and would survive being framed, take the generative route.

Side light or window light gives the model form to describe. Flat frontal flash gives it almost nothing, and the result comes back as an outline with an empty middle.

"Pen and ink", "graphite", "charcoal", "engraving" and "one continuous line" produce genuinely different drawings. The single word you pick here changes more than every other setting combined.

"No grey wash, no shading gradients" is what keeps it a line drawing. Without it, models drift toward soft pencil rendering that reads as a greyscale photo with texture on it.

"Preserve the subject's facial structure and expression exactly." Left out, the drawing is skilful and of somebody slightly different, which is the failure people notice last and mind most.

Line density varies between runs, as the four portraits above show. Generate a few and pick the density you want rather than trying to specify it numerically.

"Redraw this photograph as a fine pen-and-ink line drawing: confident cross-hatched linework, pure black ink on white paper, no grey wash and no shading gradients, preserve the subject's facial structure and expression exactly, vary line weight to describe form."

"Vary line weight to describe form." It is the difference between a drawing and a trace. Uniform line weight is exactly what makes filter output look mechanical, and asking for variation is how you avoid it.

"Fine pen-and-ink" — replace it with "soft graphite pencil", "charcoal on toned paper", "single continuous contour line" or "engraved etching". Change only this and you can see exactly what the medium word does.

Faces are what these models understand most deeply. Structure, expression and hair direction all carry through, and this is the subject where the generative route beats a filter most clearly.

The family example above holds four faces with individual expressions. Expect quality to fall away past five or six people as faces at the back simplify.

Fur direction comes out well. Say the breed, or you get a generic animal of approximately the right shape drawn very competently.

Straight lines and repeated structure are where generative models invent windows. An edge filter is both more accurate and free for this case, and we would rather say so than sell you the wrong tool.