NativeScript/tns-core-modules/image-asset/image-asset.d.ts

import { Observable } from "../data/observable";

export class ImageAsset extends Observable {
    constructor(asset: any);
    getImageAsync(callback: (image: any, error: any) => void); //UIImage for iOS and android.graphics.Bitmap for Android
    ios: any; //PHAsset
    nativeImage: any; //UIImage for iOS and android.graphics.Bitmap for Android
    android: any;
    options: ImageAssetOptions;
}

export interface ImageAssetOptions {
    width?: number;
    height?: number;
    keepAspectRatio?: boolean;
}