GammaAdjust QML Type

The following example shows how to apply the effect.

import QtQuick
import Qt5Compat.GraphicalEffects

Item {
    width: 300
    height: 300

    Image {
        id: bug
        source: "images/bug.jpg"
        sourceSize: Qt.size(parent.width, parent.height)
        smooth: true
        visible: false
    }

    GammaAdjust {
        anchors.fill: bug
        source: bug
        gamma: 0.45
    }
}

This property allows the effect output pixels to be cached in order to improve the rendering performance.

Every time the source or effect properties are changed, the pixels in the cache must be updated. Memory consumption is increased, because an extra buffer of memory is required for storing the effect output.

It is recommended to disable the cache when the source or the effect properties are animated.

By default, the property is set to false.

This property defines the change factor for how the luminance of each pixel is altered according to the equation:

luminance = pow(original_luminance, 1.0 / gamma); // The luminance is assumed to be between 0.0 and 1.0

Setting the gamma values under 1.0 makes the image darker, the values above 1.0 lighten it.

The value ranges from 0.0 (darkest) to inf (lightest). By default, the property is set to 1.0 (no change).

Output examples with different gamma values
gamma: 0.5	gamma: 1.0	gamma: 2.0

Pixel luminance curves of the above images.
Red curve: default gamma (1.0)
Yellow curve: effect applied
X-axis: pixel original luminance
Y-axis: pixel luminance with effect applied

This property defines the source item for which the luminance is going to be adjusted.