Keep same image quality after converting in swift - swift

Question

I am referring to ZImageCropper for my project to crop an image. However, it reduces the quality of the image during conversion.
I know one of the reasons the quality of image was reduced is due to UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, 1)
I have tried changing it to UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, 0) and UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, false, UIScreen.main.scale)
I reference my code from Resize and Crop 2 Images affected the original image quality It does help but when I check the quality of the image, it is still reduced. Is there any way to prevent a reduction in image quality?

Answer 1

in iOS 10 and above you can resize any UIImage without quality loss, hope this helps:
func resize(targetSize: CGSize) -> UIImage {
if #available(iOS 10.0, *) {
return UIGraphicsImageRenderer(size: targetSize).image { _ in
self.draw(in: CGRect(origin: .zero, size: targetSize))
}
} else {
return resizeImage(maxSize: targetSize.width)
}
}
func resizeImage(maxSize: CGFloat) -> UIImage {
var newWidth = size.width
var newHeight = size.height
if size.width >= maxSize {
newWidth = min(maxSize, size.width)
newHeight = maxSize * size.height / size.width
} else if size.height >= maxSize {
newHeight = min(maxSize, size.height)
newWidth = maxSize * size.width / size.height
}
UIGraphicsBeginImageContext(CGSize(width: newWidth, height: newHeight))
draw(in: CGRect(x: 0, y: 0, width: newWidth, height: newHeight))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}