Question

Does anyone know how to convert a UIImage to a Base64 string, and then reverse it?

I have the below code; the original image before encoding is good, but I only get a blank image after I encode and decode it.

NSData *imageData = UIImagePNGRepresentation(viewImage);

NSString *b64EncStr = [self encode: imageData];

NSString *base64String = [self encodeBase64:imageData];

Answer 1

Swift

First we need to have image’s NSData

//Use image name from bundle to create NSData
let image : UIImage = UIImage(named:"imageNameHere")!
//Now use image to create into NSData format
let imageData:NSData = UIImagePNGRepresentation(image)!

//OR next possibility

//Use image's path to create NSData
let url:NSURL = NSURL(string : "urlHere")!
//Now use image to create into NSData format
let imageData:NSData = NSData.init(contentsOfURL: url)!

Swift 2.0 > Encoding

let strBase64:String = imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)

Swift 2.0 > Decoding

let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)!

Swift 3.0 > Decoding

let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!

Encoding :

let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
print(strBase64)

Decoding :

let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions(rawValue: 0))!
let decodedimage:UIImage = UIImage(data: dataDecoded)!
print(decodedimage)
yourImageView.image = decodedimage

Swift 3.0

let dataDecoded : Data = Data(base64Encoded: strBase64, options: .ignoreUnknownCharacters)!
let decodedimage = UIImage(data: dataDecoded)
yourImageView.image = decodedimage

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Objective-C

iOS7 > version

You can use NSData's base64EncodedStringWithOptions

Encoding :

- (NSString *)encodeToBase64String:(UIImage *)image {
 return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}

Decoding :

- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
  NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
  return [UIImage imageWithData:data];
}

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iOS 6.1 and < version

First Option : Use this link to encode and decode image

Add Base64 class in your project.

Encoding :

 NSData* data = UIImageJPEGRepresentation(yourImage, 1.0f);
 NSString *strEncoded = [Base64 encode:data];

Decoding :

 NSData* data = [Base64 decode:strEncoded ];;
 image.image = [UIImage imageWithData:data];

Another Option: Use QSUtilities for encoding and decoding

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