Asset Management

Asset Management

Asset Catalog Structure

Xcode projects use .xcassets bundles containing named asset sets:

Assets.xcassets/
  Contents.json                    # Root catalog manifest
  AppIcon.appiconset/
    Contents.json                  # Icon set manifest with image references
    AppIcon.png                    # The actual icon file
  AccentColor.colorset/
    Contents.json                  # Color set manifest

App Icon Requirements by Platform

All platforms require a single high-resolution icon. Xcode generates all needed sizes automatically.

Contents.json Format

iOS example:

{
  "images": [
    {
      "filename": "AppIcon.png",
      "idiom": "universal",
      "platform": "ios",
      "size": "1024x1024"
    }
  ],
  "info": {
    "version": 1,
    "author": "xcode"
  }
}

macOS uses "idiom": "mac" with "scale": "1x" and no "platform" key.

Image Processing with sips

macOS includes sips (scriptable image processing system) for image manipulation:

# Query dimensions
sips -g pixelWidth -g pixelHeight image.png

# Resize to exact dimensions
sips -z 1024 1024 image.png

# Convert format to PNG
sips --setProperty format png image.jpg --out image.png

# Resize and convert in one step
sips -z 1024 1024 --setProperty format png input.jpg --out output.png

Verifying Icon Installation

To verify an icon is correctly installed:

1. Check AppIcon.appiconset/Contents.json has a filename entry
2. Verify the referenced file exists in the same directory
3. Confirm dimensions match the platform requirement using sips -g pixelWidth -g pixelHeight
4. Build the project to verify Xcode accepts the icon

Finding the Asset Catalog

Search for the asset catalog in the project:

find . -name "AppIcon.appiconset" -not -path "*/DerivedData/*" -not -path "*/.build/*"

Or use Glob: **/AppIcon.appiconset/