GetPictureId By Filename in database

I want to batch upload the photos of the products, but nopCommerce does not have such bulk import function.
Maybe because the upload time will be very large, nopCommerce does not have this batch upload function.

I first upload all the photos onto the database. Then try to import the products detail by "import from excel".
I can change the code in ImportManager.cs.
Then I can use "ProductManager.InsertProductPicture" to map the product and picture by their IDs.

But I dont know how to create a Picture with just the filename in database.

Can anybody show me the method?

Has anyone have a good way to bulk import images for products?  The Images are all named the SKU for identification.

I would be suprised if no one built this functionality already...