shape-image-threshold

Summary

Defines the alpha channel threshold used to extract a shape from an image. Can be thought of as a “minimum opacity” threshold; that is, a value of 0.5 means that the shape will enclose all the pixels that are more than 50% opaque.

Overview table

Initial value: 0.0
Applies to: Floats
Inherited: No
Media: visual
Computed value: As specified, clamped to a 0.0-1.0 range
Animatable: Yes

CSS Object Model Property
:

Percentages: [[CSS percentages::Alpha channel of the image specified by shape-outside.]]

Syntax

shape-image-threshold: <number>

Values

<number>: A numeric value used to set the opacity threshold used for extracting a shape from an image. Any values outside the range 0.0 (fully transparent) to 1.0 (fully opaque) will be clamped to this range.

Examples

Note: Depends upon an image previously specified by shape-outside.

/*
Extract a shape from an image by enclosing all pixels greater than 25% opacity
*/
#myimg {
  shape-image-threshold: 0.25;
}

View live example

Usage

 Currently implemented as an experimental feature in WebKit and Blink. This can be used with a -webkit- prefix in WebKit nightly builds and with a -webkit- prefix in Chrome Canary builds with experimental-webkit-features enabled: chrome://flags/#enable-experimental-webkit-features

Related specifications

CSS Shapes Module Level 1: W3C Candidate Recommendation