How to save resized images? - swift

Question

Good evening
I am trying to save the resized images in Documents Directory, to avoid having to resize every time it is called.
Analyzing the problem is just when I use the following line:
let jpgImageData = UIImageJPEGRepresentation (image, 1.0)
It appears that UIImageJPEGRepresentation undoes the changes made to the image and thus saves the image in the same ratio.
Anyone know a way to fix this?
Below the code:
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var imgView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
let myImageName = "image_10001.jpg"
let imagePath = fileInDocumentsDirectory(filename: myImageName)
if let image = UIImage(named:"image_10001")?.resizedImage(newSize: UIScreen.main.bounds.size){
print("Image : \(image.size.height)")
_ = saveImage(image: image, path: imagePath)
}
if let loadedImage = loadImageFromPath(path: imagePath){
print("Screen: \(UIScreen.main.bounds.size.height)")
print("Image Size: \(loadedImage.size.height)")
// let image = UIImageJPEGRepresentation(loadedImage, 0.9)
// let imgRes = UIImage(data: image!)?.resizedImage(newSize: UIScreen.main.bounds.size)
////
// let load = loadedImage.resizedImage(newSize: UIScreen.main.bounds.size)
//
// print("Load: \(load.size.height)")
//
// _ = saveImage(image: load, path: imagePath)
//
imgView.image = loadedImage
//
// imgView.image = UIImage(data: image!)?.resizedImage(newSize: UIScreen.main.bounds.size)
}
// Do any additional setup after loading the view, typically from a nib.
}
func loadImageFromPath(path: String) -> UIImage? {
let image = UIImage(contentsOfFile: path)
if image == nil {
print("missing image at: \(path)")
}
print("Loading image from path: \(path)") // this is just for you to see the path in case you want to go to the directory, using Finder.
return image
}
func getDocumentsURL() -> URL {
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
return documentsURL
}
func fileInDocumentsDirectory(filename: String) -> String {
let fileURL = getDocumentsURL().appendingPathComponent(filename)
return fileURL.path
}
func saveImage (image: UIImage, path: String ) -> Bool{
print("Save")
let url = URL(fileURLWithPath: path)
// let pngImageData = UIImagePNGRepresentation(image)
let jpgImageData = UIImageJPEGRepresentation(image, 1.0) // if you want to save as JPEG
let img = UIImage(data:jpgImageData!)
//
print("SIMG: \(String(describing: img?.size.height))")
do {
_ = try jpgImageData?.write(to: url, options: .atomicWrite)
print("Save Success")
} catch let error {
print(error)
return false
}
return true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
extension UIImage {
/// Returns a image that fills in newSize
func resizedImage(newSize: CGSize) -> UIImage {
// Guard newSize is different
guard self.size != newSize else { return self }
UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0);
self.draw(in: CGRect(x:0, y:0, width:newSize.width, height: newSize.height))
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}
/// Returns a resized image that fits in rectSize, keeping it's aspect ratio
/// Note that the new image size is not rectSize, but within it.
func resizedImageWithinRect(rectSize: CGSize) -> UIImage {
let widthFactor = size.width / rectSize.width
let heightFactor = size.height / rectSize.height
var resizeFactor = widthFactor
if size.height > size.width {
resizeFactor = heightFactor
}
let newSize = CGSize(width:size.width/resizeFactor, height:size.height/resizeFactor)
let resized = resizedImage(newSize: newSize)
return resized
}
var jpeg: Data? {
return UIImageJPEGRepresentation(self, 1) // QUALITY min = 0 / max = 1
}
var png: Data? {
return UIImagePNGRepresentation(self)
}
}
extension Data {
var uiImage: UIImage? {
return UIImage(data: self)
}
}

Answer 1

I assume you have some "old" image inside your documents directory that was saved with some older code you had (not resized).
I assume that because the code you posted will not save any new images, because of this line:
if let image = UIImage(named:"image_10001")?.resizedImage(newSize: UIScreen.main.bounds.size){
//resize code
}
I think you wanted to use here same image name just taken from bundle:
if let image = UIImage(named: myImageName)?.resizedImage(newSize: UIScreen.main.bounds.size){
//resize code
}
You can Reset Simulator Content and confirm that no image will be loaded with the code you posted here.