Contour Drawing Generator
Turn a photo or drawing into a contour drawing: lines only, no shading, following the edges where the picture changes from light to dark. Choose 1 to 12 tone levels: with 1 you get the single edge between the dark and light parts; with more, every level adds a ring of lines, like the bands of tone in a careful study. Each line is traced exactly where the picture’s lightness crosses its level, then simplified so that it never moves further from the traced edge than the tolerance you set in millimetres; very short lines can be left out. The SVG is nothing but polylines at real size, one group per level, ready for a pen plotter or a laser. There is also a printable contour practice sheet: your contour drawing as a reference, a frame to copy it, and frames for blind contour and modified contour drawing. Nothing is uploaded.
100% private — everything runs in your browser. Everything runs in your browser; nothing is uploaded.
The SVG is plain polylines at real size, one group per tone level, for pen plotters and laser engraving. Print the PDF at 100% (Actual size).
Picture
Contours
Size
Page
Runs in your browser with our own code: your picture is read on this device and nothing is uploaded or saved. The sample pictures are drawn by our code. You may use what you make here, including commercially, with no credit needed.
How to turn a picture into a contour drawing
- Add your photo or drawing, or pick one of our sample pictures.
- Choose the number of tone levels (start with 2 to 4).
- Set Simplify within and Leave out lines under, in millimetres, and the line weight.
- Download the PDF or PNG to print, or the SVG of lines for a plotter or laser.
- For practice, switch Make to the contour practice sheet and print it.
What you can use it for
- Line studies from your own photos
- Pen plotter and laser engraving art
- Blind contour and contour drawing practice
- Reference lines for painting and embroidery
- Art class line exercises
- Minimal line art for prints and cards
Tone levels and where the lines fall
| Tone levels | Lightness of each line (0% black, 100% white) |
|---|---|
| 1 | 50% |
| 2 | 33%, 67% |
| 3 | 25%, 50%, 75% |
| 4 | 20%, 40%, 60%, 80% |
| 6 | 14%, 29%, 43%, 57%, 71%, 86% |
| 8 | 11%, 22%, 33%, 44%, 56%, 67%, 78%, 89% |
The levels split the lightness range into equal steps. Brightness, contrast and Smooth out noise change the picture before it is traced.
Simplifying our 5 sample pictures
| Sample (drawn by our code) | Points, no simplifying | Points within 0.1 mm | Lines | Total length | Points within 0.25 mm |
|---|---|---|---|---|---|
| Pear lit from the left | 4244 pts | 477 pts | 8 | 1.413 m | 260 pts |
| Three pebbles | 4654 pts | 672 pts | 10 | 1.492 m | 386 pts |
| Dunes under a pale sky | 2297 pts | 220 pts | 5 | 0.779 m | 85 pts |
| Cup and saucer | 3606 pts | 380 pts | 8 | 1.31 m | 201 pts |
| Tone ramp (light to dark) | 1352 pts | 8 pts | 4 | 0.539 m | 8 pts |
4 tone levels, 180 mm wide, lines under 2 mm left out, a little smoothing. Your own picture shows its own counts in the info line.
Practice sheet frames
| Paper | Each of the 4 frames (4:3 picture) |
|---|---|
| US Letter portrait | 91.25 × 68.438 mm |
| A4 portrait | 88.3 × 66.225 mm |
| US Letter landscape | 97.667 × 73.25 mm |
| A4 landscape | 93.733 × 70.3 mm |
Frames keep the shape of your picture and are 8 mm apart. Frame 1 holds your contour drawing as the reference.
Which tool to use
| You want | Use |
|---|---|
| Contour lines at tone edges, plotter SVG, practice sheet | Contour Drawing Generator (this page) |
| Contour lines for terrain-style patterns or a height map | Topographic Map Generator |
| Line art with closed shapes to colour in | Photo to Coloring Page |
| A pencil sketch look | Image to Sketch |
| A sticker outline around a cut-out | Outline Image |
| Tone made of dots | Stipple Generator |
Also handy: the Topographic Map Generator for contour patterns, Photo to Coloring Page and the Scribble Art Generator for tone drawn as one scribbled line.
More free tools
Turning photos into drawings?
Image tools that run privately in your browser, with no sign-up and no watermark.
Frequently asked questions
What is contour drawing?
Drawing the edges of shapes with lines only, with no shading: the outer edge of a form and the edges inside it where one area meets another. This tool finds those edges where the lightness of your picture changes.
What is blind contour drawing?
Drawing your subject while looking only at the subject, never at the paper, so you follow every edge slowly with your eyes and your hand together. The result looks loose; the point is the looking. The practice sheet has a frame for it.
What is modified contour drawing?
The same slow line drawing, but you may glance at the paper now and then to place the next line, so the drawing stays closer to the subject’s proportions. The practice sheet has a frame for it.
Does it draw cross-contour lines?
No. Cross-contour lines run across the surface of a form to show its roundness, and they need the real three-dimensional shape. A flat photo only has light and dark, so the tool draws contours at tone edges and does not invent surface lines.
How are the lines found?
The tool reads the lightness of every pixel (0 = black, 100% = white) and traces each level with the marching squares method: the line crosses between two neighbouring pixels at the exact point where the lightness, blended evenly between them, equals the level. Our tests check every point of every line against that rule.
What does Simplify within mean?
The traced lines have a point at every pixel. Simplifying keeps only the points needed so that the line never strays further from the traced edge than the distance you set, for example 0.1 mm. Smaller files and smoother plotting, with a stated limit; 0 keeps every point.
Can I use the SVG with a pen plotter or laser?
Yes. The SVG holds only polylines (no fills, no images), at the real size in millimetres, with one group per tone level so you can give each level its own pen or pass. The same picture and settings always give the same file.
Is it free?
Yes. There is no sign-up, no watermark and no limit.
Is my picture uploaded?
No. Your picture is read by your browser on your own device and drawn on a canvas there; nothing is sent anywhere and nothing is stored after you close the tab.