Convert UIImage to base64 string in swift

Question

I'm trying to convert a UIImage to a base64 string with the goal of uploading it to a back-end server.

However, the conversion code I found in this article (which should be Apple's own implementation) generates an invalid string:

Convert between UIImage and Base64 string

After upload, I get this image:

[Failty image that is decoded from iOS converted base64 1

Instead of this:

[Correct image decoded from an online base64 conversion tool2

I tested the upload results using Postman and the back-end handles a valid base64 image correctly, so I narrowed the bug down to the base64 conversion itself. Here's my code:

public extension UIImage
{
     func base64Encode() -> String?
    {
        guard let imageData = UIImagePNGRepresentation(self) else
        {
            return nil
        }

        let base64String = imageData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
        let fullBase64String = "data:image/png;base64,\(base64String))"

        return fullBase64String
    }
}

Any idea how I could fix my base64 output on my iOS device before I upload it to the server?

That looks absolutely correct to me, what makes you think it's the conversion? Have you checked the conversion algorithm server side? — Jacob King
– Jacob King, Commented Nov 3, 2016 at 7:51
Try base64EncodedStringWithOptions([]). You might also have to replace "+", "/" and "=", compare stackoverflow.com/a/39376534/1187415. — Martin R
– Martin R, Commented Nov 3, 2016 at 8:19

Bhavuk Jain · Accepted Answer · 2016-11-03 08:25:54Z

4

Do it something like this:

For Encoding:

data.base64EncodedStringWithOptions([])

For decoding:

let url = URL(string: String(format:"data:application/octet-stream;base64,%@",base64String))
do {
    let data =  try Data(contentsOf: url!)
}catch {

}

edited Nov 3, 2016 at 8:25

answered Nov 3, 2016 at 8:20

Bhavuk Jain

2,1571 gold badge16 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

rmaddy Over a year ago

If you use the Data base64EncodedString(options:) method to encode the Data to a String, then use the Data init?(base64Encoded:, options:) initializer to convert the string back into Data.

KomalBadhe · Accepted Answer · 2018-01-18 12:23:31Z

2

for Swift 4, Do something like this,

For Encoding -

let imgObj = UIImage(named: "photo")    
let imageData = UIImagePNGRepresentation(imgObj!)! as NSData
let base64 = imageData.base64EncodedData(options: .lineLength64Characters)

datatype of base64 variable is Data.

answered Jan 18, 2018 at 12:23

KomalBadhe

291 bronze badge

Collectives™ on Stack Overflow

Convert UIImage to base64 string in swift

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related