Hough Transform
Detect lines or circles in images using the Hough transform. Returns an accumulator image and a table of detected features. Equivalent to Gwyddion's hough.c module.
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Input field (edge-detected images work best) |
Outputs
| Name |
Type |
Description |
| accumulator |
DATA_FIELD |
Hough accumulator space |
| detections |
RECORD_TABLE |
Table of detected lines or circles |
Controls
| Name |
Type |
Default |
Description |
| mode |
dropdown |
lines |
Detection mode: lines or circles |
| n_peaks |
INT |
3 |
Number of strongest features to report (1–50) |
| threshold |
FLOAT |
1.0 |
Minimum accumulator value relative to peak (0.1–10.0) |
| min_radius |
INT |
10 |
Minimum circle radius in pixels (circles mode only) |
| max_radius |
INT |
30 |
Maximum circle radius in pixels (circles mode only) |
Notes
- For line detection, apply Edge Detect first for best results. Lines are reported as (angle, distance) pairs.
- For circle detection, min/max radius constrains the search range. Circles are reported as (center_x, center_y, radius).
- The accumulator image visualises the parameter space — bright spots correspond to detected features.
