images.Sigmoid

This is a non-linear contrast change useful for photo adjustments; it preserves highlight and shadow detail.

The midpoint is the midpoint of contrast. It must be in the range [0, 1], typically 0.5.

The factor indicates how much to increase or decrease the contrast, typically in the range [-10, 10] where 0 has no effect. A positive value increases contrast, while a negative value decrease contrast.

Usage

Create the filter:

{{ $filter := images.Sigmoid 0.6 -4 }}

{{% include "/_common/functions/images/apply-image-filter.md" %}}

Example

{{< img src="images/examples/zion-national-park.jpg" alt="Zion National Park" filter="Sigmoid" filterArgs="0.6,-4" example=true

}}