boundingBox(for:)

Calculates the bounding box around the characters in the range of a string.

Declaration

@nonobjc func boundingBox(for range: Range<String.Index>) throws -> VNRectangleObservation?

Parameters

range:
The range of the characters in the text string to draw a bounding box around.

Return Value

A bounding box.

Discussion

Bounding boxes aren’t always an exact fit around the characters. Use them to display in user interfaces to provide general guidance, but avoid using their contents for image processing.

The bounding box that returns from this method differs based on the value of recognitionLevel, as follows:

Fast	The bounding box has character precision. When you specify a range from `0` to `1`, the value that returns is the first character’s bounding box.
Accurate	The bounding box has word precision. When you specify a range from `0` to `1`, or `1` to `2`, the value that returns is the bounding box of the whole word containing the first character.