Convert 1 image 2048x2048 to all needed sizes for an iOS app

README.md

Prerequisite

$ brew install imagemagick

This is one way to run this script:

$ time /opt/local/convertappicons/convertappicons.sh AppName.png
AppName

real	0m4.272s
user	0m5.478s
sys	0m0.547s
$ exa -T AppName
AppName
├── Icon-60.png
├── Icon-60@2x.png
├── Icon-60@3x.png
├── Icon-72.png
├── Icon-72@2x.png
├── Icon-76.png
├── Icon-76@2x.png
├── Icon-76@3x.png
├── Icon-iPadPro@2x.png
├── Icon-Small-50.png
├── Icon-Small-50@2x.png
├── Icon-Small.png
├── Icon-Small@2x.png
├── Icon-Small@3x.png
├── Icon-Spotlight-40.png
├── Icon-Spotlight-40@2x.png
├── Icon-Spotlight-40@3x.png
├── Icon.png
├── Icon@2x.png
├── iTunesArtwork
└── iTunesArtwork@2
$ open AppName

Then drag all the files from the newly opened folder on to your app icon grid.

convertAppIconsiOSXCode10.sh

#!/usr/bin/env bash

### Note that if your image is 2048 x 2048 as an example there is no need for -resize to have 2 parameters,
### however if your original image is 4097 x 4095, the 2 parameters will "correct" this.

echo ${1%.*}

/bin/mkdir "${1%.*}"

#/usr/local/bin/convert "$1" -resize '1024x1024' "${1%.*}/app_1024x1024_AppStore.png"
#/usr/local/bin/convert "$1" -resize   '180x180' "${1%.*}/app_0180x0180_iPhoneApp_60pt_3x.png"
#/usr/local/bin/convert "$1" -resize   '167x167' "${1%.*}/app_0167x0167_iPadPro_835pt_2x.png"
#/usr/local/bin/convert "$1" -resize   '152x152' "${1%.*}/app_0152x0152_iPad_76pt_2x_.png"
#/usr/local/bin/convert "$1" -resize   '120x120' "${1%.*}/app_0120x0120_iPhoneApp_60pt_2x.png"
#/usr/local/bin/convert "$1" -resize     '87x87' "${1%.*}/app_0087x0087_iPhone_29pt_3x.png"
#/usr/local/bin/convert "$1" -resize     '80x80' "${1%.*}/app_0080x0080_iPhoneSpotlight_40pt_2x.png"
#/usr/local/bin/convert "$1" -resize     '76x76' "${1%.*}/app_0076x0076_iPadApp_76pt_1x.png"
#/usr/local/bin/convert "$1" -resize     '60x60' "${1%.*}/app_0060x0060_iPhoneNotification_20pt_3x.png"
#/usr/local/bin/convert "$1" -resize     '58x58' "${1%.*}/app_0058x0058_iPhone_29pt_2x.png"
#/usr/local/bin/convert "$1" -resize     '40x40' "${1%.*}/app_0040x0040_iPhoneNotification_20pt_2x.png.png"
#/usr/local/bin/convert "$1" -resize     '29x29' "${1%.*}/app_0029x0029_iPadSettings_29pt_1x.png"
#/usr/local/bin/convert "$1" -resize     '20x20' "${1%.*}/app_0020x0020_iPadNotification_20px_1x.png"


/usr/local/bin/convert "$1" -resize     '60x60' "${1%.*}/Icon-60.png"
/usr/local/bin/convert "$1" -resize   '120x120' "${1%.*}/Icon-60@2x.png"
/usr/local/bin/convert "$1" -resize   '180x180' "${1%.*}/Icon-60@3x.png"
/usr/local/bin/convert "$1" -resize     '72x72' "${1%.*}/Icon-72.png"
/usr/local/bin/convert "$1" -resize   '144x144' "${1%.*}/Icon-72@2x.png"
/usr/local/bin/convert "$1" -resize     '76x76' "${1%.*}/Icon-76.png"
/usr/local/bin/convert "$1" -resize   '152x152' "${1%.*}/Icon-76@2x.png"
/usr/local/bin/convert "$1" -resize   '228x228' "${1%.*}/Icon-76@3x.png"
/usr/local/bin/convert "$1" -resize   '167x167' "${1%.*}/Icon-iPadPro@2x.png"
/usr/local/bin/convert "$1" -resize     '50x50' "${1%.*}/Icon-Small-50.png"
/usr/local/bin/convert "$1" -resize   '100x100' "${1%.*}/Icon-Small-50@2x.png"
/usr/local/bin/convert "$1" -resize     '29x29' "${1%.*}/Icon-Small.png"
/usr/local/bin/convert "$1" -resize     '58x58' "${1%.*}/Icon-Small@2x.png"
/usr/local/bin/convert "$1" -resize     '87x87' "${1%.*}/Icon-Small@3x.png"
/usr/local/bin/convert "$1" -resize     '40x40' "${1%.*}/Icon-Spotlight-40.png"
/usr/local/bin/convert "$1" -resize     '80x80' "${1%.*}/Icon-Spotlight-40@2x.png"
/usr/local/bin/convert "$1" -resize   '120x120' "${1%.*}/Icon-Spotlight-40@3x.png"
/usr/local/bin/convert "$1" -resize     '57x57' "${1%.*}/Icon.png"
/usr/local/bin/convert "$1" -resize   '114x114' "${1%.*}/Icon@2x.png"
/usr/local/bin/convert "$1" -resize   '512x512' "${1%.*}/iTunesArtwork"
/usr/local/bin/convert "$1" -resize '1024x1024' "${1%.*}/iTunesArtwork@2"