ChatGPT_Applying_Instagram_Filters_in_Swift

ImageFilter.swift

import UIKit
import Foundation
import CoreImage
import MetalPerformanceShaders
// MARK: - Filter Types

enum FilterType {
    case clarendon
    case gingham
    case juno
    case lark
    case mayfair
    case sierra
    case valencia
    case walden

    var filter: CIFilter {
        switch self {
        case .clarendon:
            let filter = CIFilter(name: "CIPhotoEffectChrome")!
            return filter
        case .gingham:
            let filter = CIFilter(name: "CIColorMonochrome")!
            filter.setValue(CIColor(red: 0.9, green: 0.9, blue: 0.9), forKey: "inputColor")
            filter.setValue(1.0, forKey: "inputIntensity")
            return filter
        case .juno:
            let filter = CIFilter(name: "CIColorControls")!
            filter.setValue(0.5, forKey: "inputSaturation")
            filter.setValue(1.0, forKey: "inputBrightness")
            filter.setValue(1.5, forKey: "inputContrast")
            return filter
        case .lark:
            let filter = CIFilter(name: "CIPhotoEffectTransfer")!
            return filter
        case .mayfair:
            let filter = CIFilter(name: "CIPhotoEffectProcess")!
            return filter
        case .sierra:
            let filter = CIFilter(name: "CISepiaTone")!
            filter.setValue(1.0, forKey: "inputIntensity")
            return filter
        case .valencia:
            let filter = CIFilter(name: "CIPhotoEffectFade")!
            return filter
        case .walden:
            let filter = CIFilter(name: "CIPhotoEffectInstant")!
            return filter
        }
    }
}

// MARK: - Image Filtering

struct FilteredImage {
    let image: CGImage
    let filter: CIFilter
}

class ImageFilter {
    
    private let device: MTLDevice
    private let commandQueue: MTLCommandQueue
    
    init(device: MTLDevice) {
        self.device = device
        self.commandQueue = device.makeCommandQueue()!
    }
    
    func applyFilter(_ filterType: FilterType, to inputImage: CGImage) -> FilteredImage {
        // Create CIImage from input CGImage
        let inputCIImage = CIImage(cgImage: inputImage)
        
        // Apply filter to CIImage
        let filter = filterType.filter
        filter.setValue(inputCIImage, forKey: kCIInputImageKey)
        let outputCIImage = filter.outputImage!
        
        // Create CGImage from filtered CIImage
        let context = CIContext(mtlDevice: device)
        let outputCGImage = context.createCGImage(outputCIImage, from: outputCIImage.extent)!
        
        return FilteredImage(image: outputCGImage, filter: filter)
    }
}