How to re-initialize PrimeNg Gallaria in angular 11 - primeng

Question

Need bind the newly browsed image files array to the PrimeNg gallaria.
but as it's getting blank image array at the start when initialized and when browse the image files, the new array with image files is not getting updated in the primeNg gallaria.
if anyone have any idea please help.
Additions
Code HTML -
<p-fileUpload #fubauto1 mode="basic" multiple="multiple"
name="demo1[]" accept="image/*"
maxFileSize="maxImageFileSize"
(onSelect)="onSelectImages($event)"
chooseLabel="Select Images"></p-fileUpload>
<p-galleria [(value)]="previews"
[responsiveOptions]="responsiveOptions"
[containerStyle]="{'max-width': '640px'}"
[numVisible]="3">
<ng-template pTemplate="item" let-item>
<img [src]="item" style="width: 100%; display: block;" />
</ng-template>
<ng-template pTemplate="thumbnail" let-item>
<div class="p-grid p-nogutter p-justify-center">
<img [src]="item" style="display: block;width: 50%" />
</div>
</ng-template>
<ng-template pTemplate="caption" let-item>
<h4 style="margin-bottom: .5rem; color: #ffffff;">
{{item?.title}}</h4>
<p>{{item.alt}}</p>
</ng-template>
</p-galleria>
Code Angular TS -
onSelectImages(event) {
console.log(event);
this.selectedImages = event.currentFiles;
this.previews = [];
if (this.selectedImages && this.selectedImages[0]) {
const numberOfFiles = this.selectedImages.length;
for (let i = 0; i < numberOfFiles; i++) {
const reader = new FileReader();
reader.readAsDataURL(this.selectedImages[i]);
reader.onload = (e: any) => {
this.previews.push(e.target.result);
};
}
console.log(this.previews)
}
}
As you can see in the code I am trying to browse the image files and then I have to show the selected/browsed images in gallaria slider.
so after selecting/browsing the files they are get able to shown in the gallaria.
Note- the selected files are able to shown for normal image tag as follows -
<div *ngFor="let item of previews">
<img [src]="item" style="width: 100%; display: block;" />
</div>
Problem with base64 data image array.