Scan2CAD alternative: when to trace and when to redraw
Scan2CAD is one of the best-known tools for turning scanned drawings into CAD files. It belongs to a family of raster-to-vector programs that trace the pixels of an image. Horezmi works differently: it reads the drawing and draws it again. Neither is better in general. They are good at different things, and it is worth knowing which is which before you spend an afternoon on cleanup.
How raster-to-vector software works
A vectorizing program looks at every dark pixel and fits lines, arcs and curves through them. Good ones offer clean-up tools, despeckling, character recognition for text and settings for how closely to follow the pixels. You stay in control and can tune the result for a particular kind of drawing.
What it does not know is what the lines mean. A wall, a dimension line and a hatching stroke are all just lines to it. The result keeps the drawing's look, including its flaws, and you organise it into layers and fix it by hand.
How AI redrawing works
Horezmi reads the drawing as a whole: the building outline, wall thicknesses, doors and windows, room names, the numbers on the dimension lines. Then it builds a new drawing from that understanding, with walls as walls, openings cut into them, dimensions as real dimension objects, and everything on proper layers at real scale.
The output looks like a clean drawing a drafter made, not like the scan. Faded or broken lines don't matter as long as the plan can be read. The flip side: it interprets rather than copies, so anything it reads wrong has to be corrected, which you do in plain words or by clicking an object and typing a number.
Side by side
- Scanned floor plan: tracing keeps every flaw and gives unlabelled lines; redrawing gives a clean plan with walls, openings, rooms and dimensions.
- Clean mechanical drawing or logo: tracing follows the exact shapes, which is what you want; redrawing works but is not needed.
- Photo taken at an angle: tracing needs the image straightened first; redrawing reads it as it is, if the numbers are legible.
- Text and dimensions: tracing turns them into shapes or guesses letters; redrawing keeps them as text and dimension objects.
- Where it runs: tracing programs are usually installed on your computer; Horezmi runs in the browser.
- How you pay: tracing software is typically bought or subscribed to; Horezmi charges per drawing, about $0.50 for a house plan, with $5 free at sign-in.
So which should you use?
If you convert clean line art often, a contour for cutting, a logo, a crisp part drawing, and want precise control over every curve, raster-to-vector software is the right tool.
If you mostly deal with floor plans, site plans and building drawings from scans and photos, and what you need at the end is an editable CAD plan rather than a copy of the scan, redrawing will save you the cleanup.