BUILT-IN MATHEMATICA SYMBOL

# ImageLines

ImageLines[image]
finds line segments in image and returns the coordinates of their endpoints.

ImageLines[image, t]
uses the threshold t for selecting image lines.

ImageLines[image, t, d]
uses the parameter d to control the distinctness of the detected lines.

## Details and OptionsDetails and Options

• ImageLines returns a list of line segments where the are expressed in the standard image coordinates .
• ImageLines[image, t] finds lines in the image whose normalized strength is larger than the specified threshold t.
• In ImageLines[image, t, d], the parameter d controls how close lines are suppressed. If the value is set to zero, all detected lines are returned. With d set to , only the strongest line may be returned.
• By default, ImageLines computes lines based on the Hough transform of the image, using the setting Method->"Hough".
• Lines are detected by iteratively selecting the strongest peaks in the Hough transform. Using the distinctness parameter, peaks that are within a rectangular range from the already selected peaks are excluded from the set of line candidates.
• With Method->"RANSAC", lines are detected using random sampling. For each sampling, pixels that are within a distance specified by the distinctness parameter d are used for computing the strength of the line. The pixels on the selected line are not used in the following iterations.
• By default, ImageLines returns lines that span from border to border. With a setting "Segmented"->True, detected lines may be divided into smaller segments.
• ImageLines accepts a MaxFeatures option. The default setting is . With a setting MaxFeatures->n, at most n lines with largest normalized strength are returned.

## ExamplesExamplesopen allclose all

### Basic Examples (2)Basic Examples (2)

Detect and visualize straight trajectories in a bubble chamber image:

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Detect the line going through the foreground pixels:

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