Hi,
I assume you have a tensor of image that is normalized and called img. This snippet will unnormalize image given custom mean and std.
img = img.numpy().transpose((1, 2, 0))  # numpy is [h, w, c] 
mean = np.array([0.4451, 0.4262, 0.3959])  # mean of your dataset
std = np.array([0.2411, 0.2403, 0.2466])])  # std of your dataset
img = std * img + mean
img = np.clip(img, 0, 1)
pil_image = Image.fromarray(img)

But for using ToPILImage, you need to remove first line and assume image as tensor and instead of using numpy method, use torch.. Finally, instead of last line, ToPILImage()(img) will do the trick.
Bests