Edge Detection Image Tool
Find object and texture boundaries using grayscale Sobel edge detection, then adjust edge strength or invert the result.
Upload an image to calculate its horizontal and vertical luminance edges.
Sobel edge detection
Combines horizontal and vertical luminance gradients to reveal boundaries.
Sensitivity control
Strengthen faint edges or reduce noise from detailed textures.
Light or dark background
Invert the output for white lines on black or dark lines on white.
How it works
- 1
Upload an image
Choose a photo, scan, logo, or graphic from your device.
- 2
Tune the effect
Adjust the main control and optional inversion or dithering.
- 3
Download PNG
Save the processed result at the source pixel dimensions.
Getting clearer detected edges
Images with strong contrast and clear subject boundaries produce the cleanest result. High edge strength reveals fine texture but can also amplify noise. Lower the strength for portraits or compressed images with many small artifacts.
Frequently asked questions
Which edge algorithm does this use?
It uses a 3 x 3 Sobel gradient calculation on image luminance.
Does edge detection identify objects?
No. It highlights local pixel boundaries and does not perform semantic object recognition.
Is my image uploaded?
No. Your image stays in your browser.
Edge Detection Image Tool last reviewed: Aug 2, 2026.