扫描UIImage的外观（再现CIEdgeWork）

Question

我目前正在努力重现图像的扫描外观

发现很多工作-CIFilter CIEdgeWork-是最好的（但不足以满足我的需要）。

original image

current result

expected image

非常乐意提供帮助。

Answer 1

完成删除图像饱和度并增加其亮度和对比度的操作会更容易。您将需要使用这些值来将结果微调到您的需求：

extension String {
    static let colorControls = "CIColorControls"
}

---

extension UIImage {
    var coreImage: CIImage? { CIImage(image: self) }
}

---

extension CIImage {

    var image: UIImage? { UIImage(ciImage: self) }

    func applying(brightness: Float, contrast: Float, saturation: Float) -> CIImage? {
        applyingFilter(.colorControls,
                       parameters: [kCIInputBrightnessKey: brightness,
                                    kCIInputContrastKey: contrast,
                                    kCIInputSaturationKey: saturation])
    }

    func renderedImage() -> UIImage? {
        guard let image = image else { return nil }
        return UIGraphicsImageRenderer(size: image.size,
                                       format: image.imageRendererFormat).image { _ in
            image.draw(in: CGRect(origin: .zero, size: image.size))
        }
    }
}

---

游乐场测试

let image = UIImage(data: try! Data(contentsOf: URL(string: "https://i.stack.imgur.com/KEZE6.jpg")!))!
if let coreImage = image.coreImage,
    let filteredImage = coreImage.applying(brightness: 0.5, contrast: 1.75, saturation: 0) {
    // use your filtered core image here
    // filteredImage
    // or get an UIImage from it
    // filteredImage.image
    // if you need to convert it to JPEG or PNG you would need to render your core image 
    // filteredImage.renderedImage()

}