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Opacity

This method asynchronously changes the opacity of the specified image element by setting the alpha channel (transparency) to a specified value for all pixels.

Syntax​

changeOpacity(image, alpha)

Parameters​

  • image : HTMLImageElement
    The image element to change the opacity of.

  • alpha : number
    The new alpha value (opacity) to set for all pixels (0 to 255).

    • alpha = 255: the image is completely transparent.
    • alpha = 0: the image is completely opaque.

Return​

  • Promise : Promise<HTMLImageElement>
    A promise that resolves with the image element with adjusted opacity.

Throws​

  • Error
    Thrown if the specified opacity factor is outside the valid range.

Examples​

const editpix = new EditPix();

// image url
const url = "images/img.jpg";

// create image
var image = new Image();
image.src = url;

//waiting image load
image.onload = () => {
    // change image opacity
    editpix.changeOpacity(image, 128)
        .then(resultImage => {
            // render modified image
            document.body.appendChild(resultImage);
        })
        .catch(error => { console.log(error) })
};