Applying visual effects to foreground subjects
At a glance
| Item | Summary |
|---|---|
| Purpose | Segment the foreground subjects of an image and composite them to a new background with visual effects. |
| App architecture | A Swift sample with the source-visible chain SubjectLiftingEffectsApp → ContentView → EffectsPipeline → SwiftUI / CoreImage APIs. |
| Main patterns | SwiftUI environment injection, Binding-based state propagation, Publisher-backed observable state |
| Project style | 3 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
Project structure
Source bundle/
├── SubjectLiftingEffects/
│ ├── SubjectLiftingEffectsApp.swift
│ ├── ContentView.swift
│ └── EffectsPipeline.swift
├── Configuration/
│ └── SampleCode.xcconfig
└── SubjectLiftingEffects.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 3 project/configuration file(s) and 10 source declaration(s).
Overall architecture
flowchart LR
N1["SubjectLiftingEffectsApp"]
N2["ContentView"]
N3["EffectsPipeline"]
N4["SwiftUI / CoreImage APIs"]
N1 --> N2
N2 --> N3
N3 --> N4
Reference code
SubjectLiftingEffects/SubjectLiftingEffectsApp.swift:11 — architecture anchor
@main
struct SubjectLiftingEffectsApp: 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 Vision.
Ownership and state
classDiagram
SubjectLiftingEffectsApp *-- EffectsPipeline : pipeline
EffectPicker o-- Effect : effect
BackgroundPicker o-- Background : background
ImagePicker o-- EffectsPipeline : pipeline
Ownership evidence
SubjectLiftingEffects/SubjectLiftingEffectsApp.swift:15 — stored dependency or nearest verified ownership anchor
@main
struct SubjectLiftingEffectsApp: App {
// ...
@StateObject private var pipeline = EffectsPipeline()
// ...
}| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
SubjectLiftingEffectsApp |
EffectsPipeline (pipeline) |
owns wrapper-managed state | Owning lexical scope |
EffectPicker |
Effect (effect) |
borrows mutable state | The upstream binding owner is authoritative |
BackgroundPicker |
Background (background) |
borrows mutable state | The upstream binding owner is authoritative |
ImagePicker |
EffectsPipeline (pipeline) |
stores or receives | App/module collaborators |
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
SubjectLiftingEffects/SubjectLiftingEffectsApp.swift:12 — representative type boundary
struct SubjectLiftingEffectsApp: App {
// ...
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
SubjectLiftingEffectsApp |
Application entry and top-level composition | App |
OutputView |
User-interface presentation and input forwarding | View |
ContentView |
User-interface presentation and input forwarding | View |
EffectsPipeline |
Coordinates a multi-stage processing flow | ObservableObject |
EffectPicker |
Represents a feature value or composable behavior | View |
BackgroundPicker |
Represents a feature value or composable behavior | View |
ImagePicker |
Represents a feature value or composable behavior | View |
SubImageContent |
Represents a feature value or composable behavior | View |
Effect |
Defines a closed set of feature states or choices | String, Equatable, CaseIterable |
Background |
Defines a closed set of feature states or choices | String, Equatable, CaseIterable |
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 |
|---|---|---|---|
imageSelection (SubjectLiftingEffects/ContentView.swift:46) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: keep state mutation or dependency lifetime inside the owning implementation. |
loadInputImage (SubjectLiftingEffects/ContentView.swift:57) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
outputViewSize (SubjectLiftingEffects/ContentView.swift:120) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: keep state mutation or dependency lifetime inside the owning implementation. |
processingQueue (SubjectLiftingEffects/EffectsPipeline.swift:48) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: keep state mutation or dependency lifetime inside the owning implementation. |
Reference code
SubjectLiftingEffects/ContentView.swift:46 — representative boundary
struct ImagePicker: View {
// ...
@State private var imageSelection: PhotosPickerItem? = nil
// ...
}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 | SubjectLiftingEffectsApp |
The source’s App suffix makes this role explicit. |
| Coordinates a multi-stage processing flow | EffectsPipeline |
The source’s Pipeline suffix makes this role explicit. |
| User-interface presentation and input forwarding | ContentView, OutputView |
The source’s View suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| SwiftUI environment injection | SubjectLiftingEffects/ContentView.swift:119 |
The environment supplies state or a capability without threading it through every initializer. |
| Binding-based state propagation | SubjectLiftingEffects/ContentView.swift:14 |
A binding exposes controlled read/write access while the upstream owner remains authoritative. |
| Publisher-backed observable state | SubjectLiftingEffects/EffectsPipeline.swift:37 |
Published properties notify observers while mutation remains with the state object. |
Naming conventions
- Types: App: SubjectLiftingEffectsApp; Pipeline: EffectsPipeline; View: ContentView, OutputView.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
loadInputImage,regenerate,apply,subjectMask,instances,image,loadImage,render. - Files:
SubjectLiftingEffects/SubjectLiftingEffectsApp.swift,SubjectLiftingEffects/ContentView.swift,SubjectLiftingEffects/EffectsPipeline.swift.
Architecture takeaways
SubjectLiftingEffectsAppis the main source-visible entry or composition anchor for this sample.- Framework work reaches SwiftUI, CoreImage, PhotosUI, UIKit 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 |
|---|---|
SubjectLiftingEffects/SubjectLiftingEffectsApp.swift |
SubjectLiftingEffectsApp |
SubjectLiftingEffects/ContentView.swift |
EffectPicker, BackgroundPicker, ImagePicker, OutputView, SubImageContent, ContentView |
SubjectLiftingEffects/EffectsPipeline.swift |
Effect, Background, EffectsPipeline |