How can I convert a UIimage into a Byte Array, so I can upload it into my web service?
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4 Answers
This can be done with one or two lines of code
guard let image = UIImage(named: "someImage"),
let data = image.jpegData(compressionQuality: 1.0) else { return }
// OR
guard let image = UIImage(named: "someImage"),
let data = image.pngData() else { return }
In the first instance, the number should range from 0.0 to 1.0 and sets the jpeg quality. PNG is lossless so there is no need for a compression quality value but be aware that the file size can be about 10 times higher
--- update ---
Updated for Swift 5.1
2 Comments
Daniel Oram
Does
unpackedImage refer to image? Or is there another process that needs to be implemented between creating image and creating data?
Benzy
Sorry for that,
UIImage() initialiser usually returns an optional, obviously it has to be unwrapped since the UIImageJPEGRepresentation method only accepts unwrapped objectsYou can convert UIImage to NSData and pass it to this method
func getArrayOfBytesFromImage(imageData:NSData) -> NSMutableArray
{
// the number of elements:
let count = imageData.length / sizeof(UInt8)
// create array of appropriate length:
var bytes = [UInt8](count: count, repeatedValue: 0)
// copy bytes into array
imageData.getBytes(&bytes, length:count * sizeof(UInt8))
var byteArray:NSMutableArray = NSMutableArray()
for (var i = 0; i < count; i++) {
byteArray.addObject(NSNumber(unsignedChar: bytes[i]))
}
return byteArray
}
2 Comments
H Raval
how can i perform reverse...how can i get image from bytes
Rajasekhar Pasupuleti
get your image back from the array of bytes ---> static func getImag(from bytes: [NSNumber]) -> UIImage? { return UIImage.init(data: Data.init(bytes: bytes.map({ $0.uint8Value }))) }
Swift 5, iOS 14 version based on toofani answer, minimal changes
func getArrayOfBytesFromImage(imageData:NSData) -> Array<UInt8>
{
// the number of elements:
let count = imageData.length / MemoryLayout<Int8>.size
// create array of appropriate length:
var bytes = [UInt8](repeating: 0, count: count)
// copy bytes into array
imageData.getBytes(&bytes, length:count * MemoryLayout<Int8>.size)
var byteArray:Array = Array<UInt8>()
for i in 0 ..< count {
byteArray.append(bytes[i])
}
return byteArray
}
So a complete sequence looks like this... assuming I got a UIImage I extract the data and then recombine it.
let data = imageX.pngData()
bytes = getArrayOfBytesFromImage(imageData: data! as NSData)
let datos: NSData = NSData(bytes: bytes, length: bytes.count)
newImage = UIImage(data: datos as Data) // Note it's optional. Don't force unwrap!!!
2 Comments
LilMoke
What if I just want raw data and not pngData. pngData seems to change the bytes so it thinks it is a png image.
user3069232
I think you need to convert it to png data because Apple is not going to publish their internal formats for you to play around with.
Little modifying for @user3069232
We can pass the image and compression parameter to get byte array.
func getByteArrayForImage(_ image: UIImage, compression: CGFloat = 1.0) -> Array<UInt8> {
guard let imageData = image.jpegData(compressionQuality: compression) as? NSData else { return [] }
let count = imageData.length / MemoryLayout<Int8>.size
var bytes = [UInt8](repeating: 0, count: count)
imageData.getBytes(&bytes, length:count * MemoryLayout<Int8>.size)
var byteArray = Array<UInt8>()
for byte in bytes {
byteArray.append(byte)
}
return byteArray
}