Line Contour

What is contour extraction?

This tool reduces a reference photo to its edges, the lines a hand would draw to describe the same shapes, and leaves out its values and colour. Useful any time you want a clean line drawing to practise from, or a construction underlay to build a rendering on top of.

Why artists use contour line

• Practising line quality and confident mark-making without the distraction of value or colour
• Getting a construction underlay to check proportions before committing to ink or paint
• Studying how a subject's edges actually behave: where they're hard, where they dissolve
• Producing a clean line reference for cross-hatching or other line-based techniques

How this tool works

Upload a reference and choose whether to trace shape outlines or work from raw edge detection. A colour-groups slider controls how many colour regions the shapes are drawn from, a threshold slider sets how sensitive the edge detection is, and a thickness slider adjusts the resulting line weight. A blur slider smooths the source first to avoid noisy, broken-up lines, and an invert toggle flips between black lines on white and white lines on black.

Combine with other tools

• Use Shape Simplifier first if you want the contours to follow simplified masses rather than every small edge in the photo
• Pair with Composition Analyzer's transfer grid to move a contour drawing onto a larger sheet accurately