Hi,
If your input images are bigger than [224, 224] just normalization would be enough, otherwise you need to resize all image to the aforementioned size.
Here is the official source code of evaluation step:
normalize = transforms.Normalize(mean=[0.485, 0.456, 0.406],
                                     std=[0.229, 0.224, 0.225])

transforms.Compose([
            transforms.Scale(256),  # optional
            transforms.CenterCrop(224),  # optional
            transforms.ToTensor(),
            normalize,
        ])


Source code of training using ImageNet dataset
Bests