Skip to main content
Extract all edge lines from photos, like using a pen to outline a photo, drawing out the contours and detail boundaries of objects.

​
Working Principle

Imagine you are an artist who needs to use a pen to outline a photo. The Canny node acts like an intelligent assistant, helping you decide where to draw lines (edges) and where not to. This process is like a screening job:
  • High threshold is the “must draw line standard”: only very obvious and clear contour lines will be drawn, such as facial contours of people and building frames
  • Low threshold is the “definitely don’t draw line standard”: edges that are too weak will be ignored to avoid drawing noise and meaningless lines
  • Middle area: edges between the two standards will be drawn together if they connect to “must draw lines”, but won’t be drawn if they are isolated
The final output is a black and white image, where white parts are detected edge lines and black parts are areas without edges.

​
Inputs

​
Outputs

​
Parameter Comparison

Original Image Parameter Comparison Common Issues:
  • Broken edges: Try lowering high threshold
  • Too much noise: Raise low threshold
  • Missing important details: Lower low threshold
  • Edges too rough: Check input image quality and resolution
This documentation was AI-generated. If you find any errors or have suggestions for improvement, please feel free to contribute! Edit on GitHub