Vernissage/ServicesKit/Sources/ServicesKit/ImageCompressService.swift

64 lines
2.2 KiB
Swift

//
// https://mczachurski.dev
// Copyright © 2023 Marcin Czachurski and the repository contributors.
// Licensed under the Apache License 2.0.
//
import Foundation
import AVFoundation
import UIKit
public class ImageCompressService {
public static let shared = ImageCompressService()
private init() { }
public func compressImageFrom(url: URL) async -> Data? {
return await withCheckedContinuation { continuation in
let sourceOptions = [kCGImageSourceShouldCache: false] as CFDictionary
guard let source = CGImageSourceCreateWithURL(url as CFURL, sourceOptions) else {
continuation.resume(returning: nil)
return
}
let maxPixelSize: Int
if Bundle.main.bundlePath.hasSuffix(".appex") {
maxPixelSize = 1536
} else {
maxPixelSize = 4096
}
let downsampleOptions = [
kCGImageSourceCreateThumbnailFromImageAlways: true,
kCGImageSourceCreateThumbnailWithTransform: true,
kCGImageSourceThumbnailMaxPixelSize: maxPixelSize
] as [CFString: Any] as CFDictionary
guard let cgImage = CGImageSourceCreateThumbnailAtIndex(source, 0, downsampleOptions) else {
continuation.resume(returning: nil)
return
}
let data = NSMutableData()
guard let imageDestination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else {
continuation.resume(returning: nil)
return
}
let isPNG: Bool = {
guard let utType = cgImage.utType else { return false }
return (utType as String) == UTType.png.identifier
}()
let destinationProperties = [
kCGImageDestinationLossyCompressionQuality: isPNG ? 1.0 : 0.85
] as CFDictionary
CGImageDestinationAddImage(imageDestination, cgImage, destinationProperties)
CGImageDestinationFinalize(imageDestination)
continuation.resume(returning: data as Data)
}
}
}