sips 10.4.4 - scriptable image processing system.
This tool is used to query or modify raster image files and ColorSync ICC profiles.
Its functionality can also be used through the "Image Events" AppleScript suite.
Try 'sips --help' or 'sips --helpProperties' for help using this tool

#!/bin/sh

filename="icon.png"
dirname="cutimg"
name_array=("Icon-29.png" "Icon-29@2x.png" "Icon-40@2x.png" "Icon-57.png" "Icon-57@2x.png" "Icon-120.png")
size_array=("29" "58" "80" "57" "114" "120")

mkdir $dirname

for ((i=0;i<${#name_array[@]};++i)); do
    m_dir=$dirname/${name_array[i]}
    cp $filename $m_dir
    sips -Z ${size_array[i]} $m_dir
done