Images Won't Align Vertically Properly

All the images on my page are square in ratio (rectangular photographs with extra transparent sides to make them square), but no matter how I try to drag them to all be in vertical alignment, some are many pixels off from others. It's very frustrating. Is there a solution?

This is my page: https://www.kofiperry.com/selected-works The first three images are the size I want, but I've given up on enlarging the rest because of the alignment issue. The lower four images are also off-center.