Edge Detection Tool

Extract crisp outlines and contours from any photograph using the classic Sobel edge detection operator. Useful for design, machine vision previews, coloring book art, and stylized illustration.

How it works

The Sobel operator applies two 3×3 convolution kernels — one for horizontal gradient, one for vertical — to the grayscale version of your image. For each pixel, the magnitude of the gradient vector indicates the strength of an edge. Pixels with magnitude below the chosen threshold are zeroed out.

Controls

• Threshold suppresses weak edges. Low values reveal every subtle line; high values leave only the strongest contours.
• Invert swaps black-on-white for white-on-black output, useful for coloring book pages and printable line art.

Use cases

• Quick line-art conversion for illustrations
• Coloring book and tracing template generation
• Pre-processing for computer-vision projects
• Architectural and design references
• Stylized photo effects for social posts
• Texture and pattern extraction

All processing happens locally in your browser. Output is a high-quality PNG.