Image size increases when data is retrieved from UIImage - ios

Question

When I load an image from a file path into a UIImage, the size ends up increasing. Am I doing something wrong?
let imageData = try! Data(contentsOf: imageUrl)
print("Original file size : \(imageData.count.readableSize())") // Displays 2.34 MB
let image = UIImage(contentsOfFile: imageUrl.path)
print("UIImage file size : \(image.pngData()!.readableSize())") // Displays 5.71 MB
extension Int
{
func readableSize() -> String
{
let units = ["bytes", "KB", "MB", "GB", "TB"]
var count = 0
var readableFileSize = self
while readableFileSize > 1024
{
readableFileSize = readableFileSize/1024
count += 1
}
return String(format: "%.2f", readableFileSize) + " " + units[count]
}
}
In the above code sample, assume that the image loaded is of png format.
I am looking for a way to circumvent this and get the actual data that was initially loaded
Edit: I'm trying to load an image into UIImage, resize it and then save it back into the file system. I'm looking for a way to achieve this without increasing the size of the file because of what I have described. I'm open to even an alternative to resize without loading the image into UIImage.

Answer 1

Maybe it does not answer your question but I want to share some useful information.
Code:
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let fileName = "2.png"
let fileURL = documentsDirectory.appendingPathComponent(fileName)
let imageData = try! Data(contentsOf: fileURL)
print("Original file size : \(imageData.count/1024)")
let image = UIImage(contentsOfFile: fileURL.path)
print("UIImage file size : \(image!.pngData()!.count/1024)")
Debug log as you mentioned in your question(size is different):
Original file size : 6083
UIImage file size : 14982
Conclusion:
After lot's of research and frustration, I realized that the size of
an image in document directory (14982) and size image from data is
identical (14982) that's mean when we are getting data from URL automatically compress it by the system.

Answer 2

Try this:
let remoteImageData = try? Data(contentsOf: URL(string: "https://upload.wikimedia.org/wikipedia/de/b/bb/Png-logo.png")!)
print(remoteImageData)
if let imageFileUrl = Bundle.main.url(forResource: "Png-logo", withExtension: "png") {
let imageFileData = try? Data(contentsOf: imageFileUrl)
print(imageFileData)
}
Prints:
Optional(811068 bytes)
Optional(811068 bytes)