Applying tone curve adjustments to images
At a glance
| Item | Summary |
|---|---|
| Purpose | Use the vImage library’s polynomial transform to apply tone curve adjustments to images. |
| App architecture | A Swift sample with the source-visible chain vImage_PolynomialApp → ContentView → PolynomialTransformer → Accelerate APIs. |
| Main patterns | SwiftUI environment injection, Binding-based state propagation, 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/
├── vImage-Polynomial/
│ ├── vImage_PolynomialApp.swift
│ ├── ContentView.swift
│ ├── PolynomialTransformer.swift
│ ├── PolynomialEditor.swift
│ ├── PolynomialTransformer+LAPACK.swift
│ ├── PolynomialTransformer+ImageResize.swift
│ ├── Info.plist
│ └── vImage_Polynomial.entitlements
├── Configuration/
│ └── SampleCode.xcconfig
└── vImage-Polynomial.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
flowchart LR
N1["vImage_PolynomialApp"]
N2["ContentView"]
N3["PolynomialTransformer"]
N4["Accelerate APIs"]
N1 --> N2
N2 --> N3
N3 --> N4
Reference code
vImage-Polynomial/vImage_PolynomialApp.swift:11 — architecture anchor
@main
struct vImagePolynomialApp: 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
classDiagram
vImagePolynomialApp *-- PolynomialTransformer : polynomialTransformer
ContentView o-- PolynomialTransformer : polynomialTransformer
PolynomialTransformer o-- PixelBuffer : srcInterleavedBuffer
PolynomialTransformer o-- PixelBuffer : destInterleavedBuffer
Ownership evidence
vImage-Polynomial/vImage_PolynomialApp.swift:13 — stored dependency or nearest verified ownership anchor
@StateObject private var polynomialTransformer = PolynomialTransformer()| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
vImagePolynomialApp |
PolynomialTransformer (polynomialTransformer) |
owns wrapper-managed state | Owning lexical scope |
ContentView |
PolynomialTransformer (polynomialTransformer) |
receives environment-provided state | The environment provider is authoritative |
PolynomialTransformer |
PixelBuffer (srcInterleavedBuffer) |
stores or receives | App/module collaborators |
PolynomialTransformer |
PixelBuffer (destInterleavedBuffer) |
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
vImage-Polynomial/vImage_PolynomialApp.swift:12 — representative type boundary
struct vImagePolynomialApp: App {
// ...
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
vImagePolynomialApp |
Application entry and top-level composition | App |
ContentView |
User-interface presentation and input forwarding | View |
PolynomialTransformer |
Transforms feature data or representations | ObservableObject |
PolynomialEditor |
Represents a feature value or composable behavior | View |
LAPACKError |
Represents feature failure conditions | Swift.Error |
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 |
|---|---|---|---|
selectNewImage (vImage-Polynomial/ContentView.swift:14) |
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. |
selectedIndex (vImage-Polynomial/PolynomialEditor.swift:16) |
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. |
polynomialTransformer (vImage-Polynomial/vImage_PolynomialApp.swift:13) |
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
vImage-Polynomial/ContentView.swift:14 — representative boundary
struct ContentView: View {
// ...
@State private var selectNewImage = false
// ...
}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 | vImagePolynomialApp |
The source’s App suffix makes this role explicit. |
| Transforms feature data or representations | PolynomialTransformer |
The source’s Transformer 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 | vImage-Polynomial/ContentView.swift:13 |
The environment supplies state or a capability without threading it through every initializer. |
| Binding-based state propagation | vImage-Polynomial/PolynomialEditor.swift:14 |
A binding exposes controlled read/write access while the upstream owner remains authoritative. |
| Publisher-backed observable state | vImage-Polynomial/PolynomialTransformer.swift:43 |
Published properties notify observers while mutation remains with the state object. |
Naming conventions
- Types: App: vImagePolynomialApp; Transformer: PolynomialTransformer; View: ContentView.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
setup,populatePlanarSourceBuffers,applyPolynomialsToAllChannels,calculateAndApplyPolynomial,displayPlanarDestinationBuffers,calculateCoefficients,resetValues,zeroValues. - Files:
vImage-Polynomial/ContentView.swift,vImage-Polynomial/PolynomialTransformer.swift,vImage-Polynomial/PolynomialEditor.swift.
Architecture takeaways
vImage_PolynomialAppis the main source-visible entry or composition anchor for this sample.- Framework work reaches Accelerate, SwiftUI, Cocoa, PhotosUI 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 |
|---|---|
vImage-Polynomial/vImage_PolynomialApp.swift |
vImagePolynomialApp |
vImage-Polynomial/ContentView.swift |
ContentView, ContentView_Previews |
vImage-Polynomial/PolynomialTransformer.swift |
PolynomialTransformer |
vImage-Polynomial/PolynomialEditor.swift |
PolynomialEditor |
vImage-Polynomial/PolynomialTransformer+LAPACK.swift |
LAPACKError |
vImage-Polynomial/PolynomialTransformer+ImageResize.swift |
Feature implementation |