import { NgModule } from '@angular/core';
import { ImageCropperModule } from 'ngx-image-cropper';

@NgModule({
    imports: [
        ...
        ImageCropperModule
    ],
    declarations: [
        ...
    ],
    exports: [
        ...
    ],
    providers: [
        ...
    ]
})
export class YourModule {
}

<input type="file" (change)="fileChangeEvent($event)" />

<image-cropper
    [imageChangedEvent]="imageChangedEvent"
    [maintainAspectRatio]="true"
    [aspectRatio]="4 / 3"
    [resizeToWidth]="128"
    format="png"
    (imageCropped)="imageCropped($event)"
    (imageLoaded)="imageLoaded()"
    (cropperReady)="cropperReady()"
    (loadImageFailed)="loadImageFailed()"
></image-cropper>

<img [src]="croppedImage" />

import { ImageCroppedEvent } from 'ngx-image-cropper';

export class YourComponent {
    imageChangedEvent: any = '';
    croppedImage: any = '';
    
    fileChangeEvent(event: any): void {
        this.imageChangedEvent = event;
    }
    imageCropped(event: ImageCroppedEvent) {
        this.croppedImage = event.base64;
    }
    imageLoaded() {
        // show cropper
    }
    cropperReady() {
        // cropper ready
    }
    loadImageFailed() {
        // show message
    }
}

if (!HTMLCanvasElement.prototype.toBlob) {
  Object.defineProperty(HTMLCanvasElement.prototype, 'toBlob', {
    value: function (callback, type, quality) {
      var dataURL = this.toDataURL(type, quality).split(',')[1];
      setTimeout(function() {

        var binStr = atob( dataURL ),
            len = binStr.length,
            arr = new Uint8Array(len);

        for (var i = 0; i < len; i++ ) {
          arr[i] = binStr.charCodeAt(i);
        }

        callback( new Blob( [arr], {type: type || 'image/png'} ) );

      });
    }
  });
}