Chevron DownAPI Reference

Image Utilities

A small set of image utility functions functions intended to help write image handling code that works across platforms.

Background: The image returned by the ImageLoader depends on the environment, i.e. whether the application is running in a new or old browser, or under Node.js.

Usage

E.g., the getImageData method enables the application to get width, height and pixel data from an image returned by the ImageLoader in a platform independent way:

import {ImageLoader, getImageSize, getImageData} from `@loaders.gl/images`;
import {load} from `@loaders.gl/core`;

const image = await load(URL, ImageLoader);

// Get an image data object regardless of whether the image is already an `Image`, `ImageBitmap` or already an image data object
const imageData = getImageData(image);
console.log(imageData.width, imageData.height, imageData.data);

Functions

isImageTypeSupported(type : string) : boolean

  • type: value to test

Returns true if type is one of the types that @loaders.gl/images can use on the current platform (depends on browser, or whether running under Node.js).

isImage(image : any) : boolean

  • image: An image returned by an image category loader, such as ImageLoader

Returns true if image is one of the types that @loaders.gl/images can return.

getImageType(image : any) : String

Returns the type of an image. Can be used when loading images with the default setting of options.type: 'auto' to discover what type was actually returned.

  • image: An image returned by an image category loader, such as ImageLoader

Returns

  • a string describing the type of the image.

Throws

  • if image is not of a recognized type.
TypeJavaScript TypeDescription
dataImage data object: data, width, height ..Node.js representation
imagebitmapImageBitmapThe newer HTML5 image class (modern browsers only)
imageImage aka HTMLImageElementMore widely supported (but less performant and flexible) image class

getImageData(image : any) : Object

  • image: An image returned by an image category loader, such as ImageLoader

Returns and image data object with the following fields

  • data typed array containing the pixels of the image
  • width
  • height

Throws

  • if image is not of a recognized type.