Sample CodemacOSReviewed 2026-07-21View on Apple Developer

Compressing an image using linear algebra

At a glance

Item Summary
Purpose Reduce the storage size of an image using singular value decomposition (SVD).
App architecture A Swift sample with the source-visible chain SVDImageCompressionAppContentViewAccelerate APIs.
Main patterns SwiftUI environment injection, Publisher-backed observable state
Project style 6 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── ImageDenoiser/
│   ├── SVDImageCompressionApp.swift
│   ├── ContentView.swift
│   ├── Matrix.swift
│   ├── SVDImageCompressor.swift
│   ├── MatrixMultiply.swift
│   ├── MatrixSVD.swift
│   ├── ImageDenoiser.entitlements
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── ImageDenoiser.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

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 5 project/configuration file(s) and 5 source declaration(s).

Overall architecture

Reference code

ImageDenoiser/SVDImageCompressionApp.swift:10 — architecture anchor

@main
struct SVDImageCompressionApp: App {
    // ...
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into Accelerate.

Ownership and state

Ownership evidence

ImageDenoiser/SVDImageCompressionApp.swift:13 — stored dependency or nearest verified ownership anchor

@main
struct SVDImageCompressionApp: App {
    // ...
    @StateObject private var imageCompressor = SVDImageCompressor(image: #imageLiteral(resourceName: "Flowers_square.jpeg"))
    // ...
}
Owner Object or state Relationship Mutation authority
SVDImageCompressionApp SVDImageCompressor (imageCompressor) owns wrapper-managed state Owning lexical scope
ContentView SVDImageCompressor (imageCompressor) receives environment-provided state The environment provider is authoritative
Matrix Int (rowCount) owns value state Initialized by the owner; the binding is immutable
Matrix Int (columnCount) owns value state Initialized by the owner; the binding is immutable

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

ImageDenoiser/SVDImageCompressionApp.swift:11 — representative type boundary

struct SVDImageCompressionApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
SVDImageCompressionApp Application entry and top-level composition App
ContentView User-interface presentation and input forwarding View
Matrix Represents a feature value or composable behavior Concrete collaborators/imported frameworks
MatrixDataReference Owns feature behavior and collaborator lifecycle Concrete collaborators/imported frameworks
SVDImageCompressor Owns feature behavior and collaborator lifecycle ObservableObject

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

Access control

Symbol Access Verified effect Likely rationale
rowCount (ImageDenoiser/Matrix.swift:13) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
columnCount (ImageDenoiser/Matrix.swift:16) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
count (ImageDenoiser/Matrix.swift:19) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
data (ImageDenoiser/Matrix.swift:24) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.

Reference code

ImageDenoiser/Matrix.swift:13 — representative boundary

public struct Matrix {
    // ...
    public let rowCount: Int
    // ...
}

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

Logic Owning type or file Placement rationale
Application entry and top-level composition SVDImageCompressionApp The source’s App suffix makes this role explicit.
User-interface presentation and input forwarding ContentView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
SwiftUI environment injection ImageDenoiser/ContentView.swift:12 The environment supplies state or a capability without threading it through every initializer.
Publisher-backed observable state ImageDenoiser/SVDImageCompressor.swift:18 Published properties notify observers while mutation remains with the state object.

Naming conventions

  • Types: App: SVDImageCompressionApp; View: ContentView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: indexIsValid, applyAdjustment, compressImagePlanarF, multiply, svd.
  • Files: ImageDenoiser/SVDImageCompressionApp.swift, ImageDenoiser/ContentView.swift, ImageDenoiser/Matrix.swift, ImageDenoiser/SVDImageCompressor.swift.

Architecture takeaways

  • SVDImageCompressionApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches Accelerate, SwiftUI, Cocoa, simd 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

Source file Relevant symbols
ImageDenoiser/SVDImageCompressionApp.swift SVDImageCompressionApp
ImageDenoiser/ContentView.swift ContentView, ContentView_Previews
ImageDenoiser/Matrix.swift Matrix, MatrixDataReference
ImageDenoiser/SVDImageCompressor.swift SVDImageCompressor
ImageDenoiser/MatrixMultiply.swift Feature implementation
ImageDenoiser/MatrixSVD.swift Feature implementation