Highlighting Areas of Interest in an Image Using Saliency

At a glance

Project structure

Source bundle/
├── ImageSaliency-iOS/
│   ├── AppDelegate.swift
│   ├── SaliencyViewController.swift
│   ├── Base.lproj/
│   │   ├── LaunchScreen.storyboard
│   │   └── Main.storyboard
│   └── Info.plist
├── ImageSaliency-macOS/
│   ├── AppDelegate.swift
│   ├── SaliencyViewController.swift
│   ├── Base.lproj/
│   │   └── Main.storyboard
│   ├── ImageSaliency.entitlements
│   └── Info.plist
├── Common-Vision-Code/
│   └── VisionSaliency.swift
└── Configuration/
    └── SampleCode.xcconfig

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Swift.
• The verified tree contains 9 project/configuration file(s) and 6 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["ImageSaliency-iOS"]
    V2["ImageSaliency-macOS"]
    Boundary["Vision APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

ImageSaliency-iOS/AppDelegate.swift:10 — architecture anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}

Interpretation

The branches represent separate entry-bearing project variants in the downloaded bundle, not runtime calls between those variants. Each branch is intentionally collapsed at the documented framework boundary; the detailed target-local flow remains in the cited files. Ownership is claimed only where the next section cites a stored property or assignment.

Ownership and state

classDiagram
    AppDelegate o-- UIWindow : window
    SaliencyViewController o-- UISegmentedControl : viewModeToggle
    SaliencyViewController o-- UISegmentedControl : saliencyTypeToggle
    SaliencyViewController o-- AVCaptureSession : session

Ownership evidence

ImageSaliency-iOS/AppDelegate.swift:13 — stored dependency or nearest verified ownership anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

ImageSaliency-iOS/AppDelegate.swift:11 — representative type boundary

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

Common-Vision-Code/VisionSaliency.swift:24 — representative boundary

public func processSaliency(_ type: SaliencyType,
                            on pixelBuffer: CVPixelBuffer,
                            orientation: CGImagePropertyOrientation) -> VNSaliencyImageObservation? {
    // ...
}

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: Controller: SaliencyViewController; Delegate: AppDelegate.
• Protocols: no local protocol declaration in the scanned source.
• Methods: applicationShouldTerminateAfterLastWindowClosed, processPixelBuffer, updateLayersContent, updateLayersGeometry, updateLayersVisibility, viewDidLoad, viewDidAppear, viewDidLayoutSubviews.
• Files: ImageSaliency-iOS/AppDelegate.swift, ImageSaliency-macOS/AppDelegate.swift, ImageSaliency-iOS/SaliencyViewController.swift, ImageSaliency-macOS/SaliencyViewController.swift.

Architecture takeaways

• AppDelegate is the main source-visible entry or composition anchor for this sample.
• Framework work reaches Vision, Cocoa, UIKit, AVFoundation through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation