Detect lines

POST /api/image-detect-lines

Detect straight lines in an image. Returns each line as a pair of endpoints. Useful for finding edges of buildings, roads, table boundaries.

Finds straight lines in an image using the probabilistic Hough transform. Returns each line as `{x1, y1, x2, y2}`. Tunable: minimum line length, maximum gap between segments considered the same line, accumulator threshold. Defaults are OK for natural images; raise the threshold to find only the longest, most prominent lines.

Inputs

Name	Type	Default	Description
image*	file	—	Input image bytes.
cannyLower	number (0…1000)	50	Canny lower hysteresis threshold.
cannyUpper	number (0…1000)	150	Canny upper hysteresis threshold.
threshold	number	80	Hough accumulator vote threshold.
minLineLength	number	30	Minimum line segment length in pixels.
maxLineGap	number	10	Maximum allowed gap (px) when joining a single line.

Response

Modes: json. Cache: yes (24h TTL).