Are you familiar with File > Automate > Fit Image and the Crop Tool settings in the Options Bar?
You may have to explain more clearly what you want.
I just read it and was'nt that good explained.
First of all i use a very old and slow CMS for the website, but i works.
When i have to upload images, i have to make them all fit before upload because of lack of a automated crop function on the site.
Thats way I do it that way right now.
I have a master canvas that is empty.
Then i paste in a image an make it fit the canvas and then save it as a new image
Then I can start uploading image to my CMS.
So the question is, is there a easy way with Photoshop to make the image center on the canvas, crop or resize the image so it fit for the canvas?
Which version of Photoshop?
An Action might suffice for the centring and resizing, but a Script might be needed to automatically save the image with a new name.
Also pasting might be a worse idea than placing the image as a Smart Object.