Mass reduction and cropping of pictures. How?

Question

linux

Here is a command that works well, but changes filenames(

convert -resize 250 -gravity Center -crop 150x150+0+0 *.jpg 1/

Actually, what is required: take pictures from the folder, resize, align to the center, crop.
After all operations, we transfer the files to folder 1.
Important : We transfer with the preservation of names!
Problem with filenames.
How to write a command here?

Answer 1

I found the solution myself
Taken from here

Answer 2

If you do not disdain the GUI, then I recommend the xnconvert cross-platform software .

Answer 3

How to write a command here?

It must be written as functions: the first function will convert one file, as it should; the second function feeds the file to the first function and saves the result as it should.