How can I create dynamic ngFor loop in Ionic 2

Ionic Framework ionic-v3
1

ion-row will be repeat after every 4 ion-col. Help in iterating please.

<ion-row>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-01.jpg" [navPush]="galleryDetail" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-02.jpg" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-03.jpg" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-04.jpg" />
            </ion-col>
        </ion-row>
        <ion-row>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-05.jpg" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-06.jpg" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-07.jpg" />
            </ion-col>
            <ion-col width-25>
                <img src="assets/images/06-Gallery/gallery-image-08.jpg" />
            </ion-col>
        </ion-row>
2

ion-row style=“flex: 0 0 calc( 100% / 4 );”