Auto-Trace an image (logo or clip art)
Use Auto-Trace when you have a logo, an icon, or clip art with a few flat colors and want stitches without drawing every shape yourself. You end with an editable design in which each color area is already a fill, a satin, or a running line, in a sewing order planned for you. It works best on artwork with a handful of solid colors and crisp edges; for a continuous-tone photograph, use Photostitch instead.
It's one of the three Auto-digitize methods, alongside Photostitch (photos) and Cross-stitch (pixel art). All three run on your own computer.
Auto-Trace is also the last step of Vector stylization, which redraws a photo as flat color shapes and then hands the picture here to be traced.
A PNG logo in three flat colors on a white background, to sew 80 mm wide on the left chest.
- Drop the PNG. A plain white backdrop doesn't need Remove background.
- Leave Color mode on Automatic. If near-identical shades show up as separate threads, drag Color grouping toward Fewer colors.
- Untick Stitch the background, so the white around the logo is not sewn as a fill and the polo shows through instead.
- Set the width to 80 mm. The trace redoes itself at that size.
- Leave Automatic stitch type on, and read the line under the preview that counts the tatami, satin, and running objects you will get.
- Click Import once the preview has settled.
Open it
Click Auto-digitize in the tool rail's Automation group (or File → Import → Auto-digitize…), then pick Auto-Trace from the method chooser.
New in v1.3.0, the chooser holds only the methods that run on your own computer, and its heading says so: your images never leave the device. A second entry, Advanced auto-digitize, holds three methods that run on Boldbobbin's servers and cost credits. See Advanced auto-digitize.
Trace an image
Auto-Trace is a three-step wizard: Choose an image, Prepare the image, then Trace & stitch settings.
- Drop an image onto the dialog, or click to choose one. Auto-Trace reads PNG, JPEG, WebP, GIF, BMP, and SVG. (Dropping a picture onto the editor window also offers Auto-trace into stitches, which opens this dialog with the picture already chosen.)
- Prepare it: optionally remove the background so the backdrop never becomes stitches.
- Trace & stitch settings is one screen: the Trace settings on the left, and the import settings (size, stitch types, pull compensation) beside them. A live preview, captioned with your hoop, traces the image and updates as you change anything; it pulses while it recalculates. It opens on the Stitch view, the stitches the import will make; switch to Vector for the traced shapes, or to Realistic to see the thread (when your computer can show Realistic). A small thumbnail of your source sits beside the controls, with Choose a different image to swap it.
- When it looks right, click Import. The button stays greyed out while a new trace is still being worked out, so what you import is always what the preview shows.
Clicking outside the chooser dialogs does not close them, so you can't lose your place mid-decision.
Remove the background
To keep a backdrop (a wall, a table, a sky) from becoming stitches, cut the subject out in the prepare step with Remove background. A plain, single-color backdrop doesn't need it: untick Stitch the background instead, which leaves it out more cleanly.
Your original sits next to the live cutout on a checkerboard, and a Sensitivity slider (down to 1%) re-cuts instantly as you move it: toward Keep more keeps more of the picture, toward Trim more cuts closer to the subject. You see exactly what is being kept before you trace.
Background removal runs on your own computer, on desktop and in the browser. Nothing is uploaded, and it works offline.
Photostitch has the same prepare step.
Trace settings
- Color mode:
- Automatic (default): Auto-Trace decides how many thread colors to use by grouping similar colors, and shows the count it found ("Detected 5 colors"). The Color grouping slider nudges that: toward More colors keeps close shades apart (more threads), toward Fewer colors folds near-identical shades into one thread (fewer thread changes).
- Exact count: you set the Number of colors (2 to 16, default 6), and the trace uses exactly that many, up to however many distinct colors the image actually contains. If the image has fewer, Auto-Trace tells you it traced fewer.
- Detail: how closely the traced outlines follow the edges in the picture, in mm. It changes the shapes, not the colors. Lower hugs every wiggle (more faithful, more stitches); higher gives smoother, simpler outlines. Default 0.05 mm (it was 0.15 before v1.3.2), from 0.02 to 1. Type a value or drag the slider. For example, a hand-lettered logo whose brush edges you want to keep reads better near the default, while a geometric logo with clean curves can go higher for smoother edges. As of v1.3.2, traced outlines use far fewer nodes for the same shape, so they are lighter to edit.
- Smooth (reduce noise) (on by default): evens out pixel and JPEG noise before colors are chosen, so flat areas don't break up into speckly shades. It matters for photos and JPEGs; clean vector art doesn't need it.
- Remove speckles (on by default): cleans away specks and pinholes too small to sew, judged at the size you import, in millimetres rather than pixels. A speck takes the color of the area around it, and a pinhole or a hairline slit is closed. Turn it off to keep everything.
- Stitch the background (on by default, new in v1.3.2): sews the plain background around the design as a fill behind it. Keep it for a patch or badge whose ground should be sewn; untick it to stitch only the design, for example a logo on a shirt. It is hidden while Remove background is on, because a removed background is never stitched.
Overlaps are resolved automatically. As of v1.3.2, changing the width or height re-traces, because the trace is cleaned up at the size the design will be sewn: a speck that is invisible at 50 mm can be a whole stitch region at 200 mm.
Some things Auto-Trace always does, with no setting:
- Near-blacks are one thread. Two blacks a shade apart become the same color.
- Small pictures still trace smoothly. A low-resolution picture comes out with smooth edges, not stair steps.
What the import makes
With Automatic stitch type on, which is the default for Auto-Trace, each traced region gets the stitch that suits its shape, at the size you import (new in v1.3.2):
| Region | Becomes |
|---|---|
| A hairline | Running stitch (a triple run for a bolder line) |
| A small dot, or a narrow band no wider than Max satin width (7 mm) and long enough for its width | Inner satin |
| A net of lines (linework) | Cut into satin columns, running lines, and small tatami fills |
| Everything else | Tatami |
Max satin width (mm) (default 7) and Min length ÷ width (default 4) tune where satin stops. Lower the width, or raise the ratio, and more bands become tatami; satin wider than about 7 mm sews long, loose stitches that can snag. Map everything to tatami makes every region tatami instead, and keeps the rest of the plan. Turn Automatic stitch type off and every region is a tatami, in the order traced, with none of the planning below.
The sewing order is planned for you, so the design sews cleanly with few stops:
- Lines and satin details land on top of the fills they touch.
- Color changes and trims are kept to a minimum, and the order inside one color is planned too.
- Where it can, the thread between two parts of the same color is hidden under later stitching instead of cut. These short travel runs show in Layers as small running-stitch objects. Where nothing can hide it, you get a trim.
- Neighboring fills overlap slightly, so fabric cannot show through the seam between them.
- A detail inside one color (a satin stripe, a small stroke) is sewn on top of a complete fill of that color, so no gap opens around it.
Entry and exit points are part of the plan, so Optimize entry & exit points is skipped. A busy picture can take several seconds; meanwhile a list over the preview shows each step as it goes, ticking off the ones done and, where it can, saying how far it is ("34 of 87"). Under the preview, a line counts the result: "18 tatami, 6 satin, 4 running". A note such as "2 strokes filled where satin would not sew" tells you how many parts became tatami instead.
Exporting
You can trace and preview for free, with no limit on how much you experiment. Exporting or publishing a design that includes auto-digitized content needs Pro. You can keep editing it for free either way. See Plans and credits.
If the result looks wrong
- The white (or other plain color) around the design is sewn: untick Stitch the background.
- Too many near-identical threads: in Automatic mode, drag Color grouping toward "Fewer colors", or switch to Exact count and set a small number.
- Import is greyed out: a new trace is still being worked out after you changed a setting or the size. Wait for the preview to settle. If the trace failed, change a setting to try again.
- You want plain fills, no satin: tick Map everything to tatami, or turn Automatic stitch type off.
- Too much satin, or satin that is too wide: lower Max satin width, or raise Min length ÷ width.
- Edges look rough or blocky: lower Detail for a closer trace, and keep Smooth on if the source is a noisy photo or JPEG.
- Stray specks of color: make sure Remove speckles is on.
- It's a photo, not a logo: Auto-Trace is for flat, few-color art. For a photograph, use Photostitch.