iOSDC Japan 2025 発表関連のコード

Request.swift

//
//  Request.swift
//  VisionFrameworkDemo
//
//  Created by tomohiro-imaizumi on 2025/09/19.
//

import CoreGraphics
import Vision

/// iOS17までの書き方
func performLegacyDetectionRequest(
    cgImage: CGImage,
    orientation: CGImagePropertyOrientation
) async throws -> [CGRect] {
    let request = VNDetectFaceRectanglesRequest()
    request.preferBackgroundProcessing = true
    // シミュレーターではCPUを使用
    #if targetEnvironment(simulator)
        if #available(iOS 17.0, *) {
            let allDevices = MLComputeDevice.allComputeDevices
            for device in allDevices {
                if device.description.contains("MLCPUComputeDevice") {
                    request.setComputeDevice(.some(device), for: .main)
                    break
                }
            }
        } else {
            request.usesCPUOnly = true
        }
    #endif

    let handler = VNImageRequestHandler(
        cgImage: cgImage,
        orientation: orientation
    )
    return try await withTaskCancellationHandler {
        try Task.checkCancellation()
        return try await withCheckedThrowingContinuation { continuation in
            do {
                try handler.perform([request])
                continuation.resume(
                    returning: (request.results ?? []).map {
                        VNImageRectForNormalizedRect($0.boundingBox, Int(cgImage.width), Int(cgImage.height))
                    }
                )
            } catch {
                continuation.resume(throwing: error)
            }
        }
    } onCancel: {
        request.cancel()
    }
}

/// iOS18以降での書き方
@available(iOS 18.0, *)
func performDetectionRequest(
    cgImage: CGImage,
    orientation: CGImagePropertyOrientation
) async throws -> [CGRect] {
    let request = DetectFaceRectanglesRequest()
    let size: CGSize = .init(width: Int(cgImage.width), height: Int(cgImage.height))
    return try await request
        .perform(on: cgImage, orientation: orientation)
        .map {
            $0.boundingBox.toImageCoordinates(size, origin: .upperLeft)
        }
}