Allows you to create custom thumbnail sizes beyond the default
thumbnail sizes found in
Settings > Media.
Changes won’t take effect until you rebuild the thumbnails.
Due to restrictions with the WordPress file names, you can’t have two image sizes with the same with and height and different cropping options. The best work around is to adjust the dimensions by 1 pixel and then resize the image in CSS.
Adding a new custom image size will not affect images that have already been uploaded, only images uploaded after the custome image size has been added. To amend previously uploaded images, you will need to re-build the thumbnails. We recommend Regenerate Thumbnails.
Width: 640px, Height 480px, Crop: No cropping
Width: 250px, Height: 250px, Crop: Top / Left
Width: 251px, Height: 251px, Crop: Center / Center
Width: 252px, Height: 252px, Crop: Bottom / Right