UIImage Object Not Formed Using NSData

Question

I am getting the following response from a server:

{
    "userId": "72e823ebc0c07fa99f279d6435e2c6ce",
    "userHash": null,
    "md5": "e993b7e9ec74bcdc1b1b7baec7d1cdd2",
    "highres": null,
    "thumbnail": "/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0
Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAAyADIDASIAAhEBAxEB/
8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQAAAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2Jygg
kKFhcYGRolJicoKSo0NTY3ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWmp6ipqrKztLW2t7i5usLDxMXGx8jJytL
T1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEAAwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSExBhJ
BUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElKU1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZa
XmJmaoqOkpaanqKmqsrO0tba3uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD0CfRbZY3IzuAyOak0nTLOW0UzBt+e
cGpppcxvg87ajt76Cw0R7uVC3lgtj1rREMvtpVijo6q+5fu81Wu/EGmeFFMlwTiTkgHmnadqqanYwXqL5ayDIU9q8C8ceILq+8QXUU0haOFyqgelVo9xHu1v8U9BuLhIlM
g3fxHGBXWf2pYmAzLdRMgXdw4NfImmQXN1bNIHKQbsbj616DpdvcQ6RHsnLfNyc1jNpbGqi+p6+fHOmgkbJePaivMvN9jRWPOyuU6Rb9ZbaTyn3Ng4Feaaj48utIuNQ0
+6gaaOZNiKT/q/etvSPEEN1qr2dsoMAXcJMdTXJ61aaLe+K7v+2b1rSIAbSozmutbmD2Lnhzxvq2h26me1e6tZB+7JPCCuauBHqGvTXV04hjuHL4Pato+CdcvlWTSZGn0w/
wCpdmxkV01v8IIZbWOa51NhPtyybhhT6U7Kw07M56xvbGK3NpFGrpuyYx39627PXoJrmSwtYgFij35Hc+ldX4L8IDStMvoryxtpk2vtuHYbhxxXiVrcTaZ4gujAxk3uynJ6DN
YOkbqonY7I+KLgEj+zz+dFZWQeTIaKz9ia3j3I9F1+8e2ElrDArg5cnj5awdfli1PUJbqR/vDtWTBev9i+zKSOc5FUHDocFifxrpujiOoj8b6vDpkelQymOCIbUKNg4qEajrcoBW/
uMe8hrnIpPLmRm6A1urq8JRRtORTTBov2q+JtRlFtb6jcDdxgykA1txfC3xRBKks3kruIO5nxmsrRdVd7sKgwi/MD7ivZ/C+taV490waVq8rRX0XKurbQQOlS2UkcaPh5reB+
9tf+/gor0j/hVqZ4upsf9dDRSuOx8q2v3z9KJetFFBmyCTotSRfdNFFNF9Do/DvR/oa2vCrMPEdphiP346H3oopD6H1un+rX6CiiipGf/9k="
}

Thumbnail is a byte array and I want to convert that into NSData, then into an UIImage.

When I do the following, I end up with nil:

  NSData *pictureData = [NSData dataWithBytes:[updatedData objectForKey:@"thumbnail"]];

  UIImage *img = [[UIImage alloc] initWithData:pictureData];

How can I fix this?

possible duplicate http://stackoverflow.com/questions/11860830/byte-array-to-nsdata — Adnan Aftab, Jan 17 '14 at 13:07
Are you sure that `thumbnail`content is not base64 encoded ? — KIDdAe, Jan 17 '14 at 13:09
Is "updatedData" already parsed NSDictionary from parsed JSON ? — Grzegorz Krukowski, Jan 17 '14 at 13:18

score 5 · Accepted Answer · answered Jan 17 '14 at 13:43

This is not a "byte array". This is a NSString which contains a Base64 encoded image.

iOS7 has built in support for Base64 encoded data, for older versions you have to roll your own code. There are plenty of implementations available

This works on iOS7:

//    NSString *base64String = [updatedData objectForKey:@"thumbnail"];
    NSString *base64String = @"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";

    NSData *data = [[NSData alloc] initWithBase64EncodedString:base64String options:NSDataBase64DecodingIgnoreUnknownCharacters];
    UIImage *image = [UIImage imageWithData:data];

And that's your image: enter image description here

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSConcreteData initWithBase64EncodedString:options:]: unrecognized selector sent to instance 0x1f551280' — rahulchona, Jan 17 '14 at 14:30
My guess is that "updatedData" doesn't really contain a parsed JSON dictionary — Stavash, Jan 17 '14 at 15:08
As I said, this if for iOS7 only. If you have to support older versions you have to implement Base64 on your own. — Matthias Bauch, Jan 17 '14 at 17:47

UIImage Object Not Formed Using NSData

1 Answers1