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