reference

`labkit.app.interaction.scaleBarGeometry`

Compute serializable image scale-bar overlay geometry.

Syntax

geometry = labkit.app.interaction.scaleBarGeometry(imageSize, ...
calibration, barLength, position, colorName)

Inputs

imageSize: Numeric vector whose first two elements are positive finite image height and width in pixels.
calibration: Struct with a positive finite pixelsPerUnit field and a unit field, normally returned by scaleBarCalibration.
barLength: Positive finite physical length expressed in calibration.unit.
position: Text containing "top" or "bottom" and optionally "left", "center", or "right". Unrecognized vertical text uses bottom; unrecognized horizontal text uses center.
colorName: "White" selects [1 1 1]. Every other value selects black.

Outputs

geometry: Scalar data struct with the fields described below.

Geometry Fields

line: Two-by-two [x y] endpoints in image-pixel coordinates.
label: Display text containing barLength and calibration.unit.
color: RGB triplet selected by colorName.
labelPosition: One-by-two centered label position in image pixels.
verticalAlignment: "top" for a top bar or "bottom" for a bottom bar.
pixelsPerUnit: Calibration value copied into the geometry.
unit: Unit label copied into the geometry as a string scalar.
barLength: Requested physical length.
position: Supplied position text as a string scalar.
colorName: Supplied color text as a string scalar.

Description

The helper places the line with an eight-percent image-edge margin and a five-pixel minimum inset. It errors when the requested bar cannot fit in the available horizontal span. Apps and renderers own drawing; this function creates no graphics and is suitable for saved project state.

Errors

labkit:app:interaction:InvalidImageSize: imageSize lacks positive finite height and width.
labkit:app:interaction:InvalidScaleBar: calibration or barLength is not a positive finite scalar.
labkit:app:interaction:ScaleBarTooLong: The requested bar does not fit inside the horizontal margins.

Example

cal = labkit.app.interaction.scaleCalibration(80, 20, "mm");
geometry = labkit.app.interaction.scaleBarGeometry( ...
[600 800], cal, 10, "Bottom right", "White");
assert(abs(diff(geometry.line(:,1))) == 40)

labkit.app.interaction.scaleCalibration — Convert a known image distance into pixels per unit.
labkit.app.interaction.anchorPath — Declare an editable open or closed path on one plot axis.
labkit.app.interaction.interpolateAnchorPath — Build a visible path through image anchor points.
labkit.app.interaction.interval — Declare an editable one-dimensional plot interval.
labkit.app.interaction.pairedAnchors — Declare matching editable points across plot axes.
labkit.app.interaction.pointSlots — Declare a fixed set of editable labeled point positions.
labkit.app.interaction.rectangle — Declare an editable rectangular plot region.
labkit.app.interaction.regionSelection — Declare a transient click-or-drag region gesture.

Source

This page is generated from the MATLAB help text in +labkit/+app/+interaction/scaleBarGeometry.m.

labkit.app.interaction.scaleBarGeometry