Convert JSON response containing byte[] to UIImage - objective-c

Question

I am working with an API that is sending me a JSON response containing an NSArray of bytes represented with integers.
See link for example (bottom example).
http://developer.yodlee.com/Indy_FinApp/Aggregation_Services_Guide/Aggregation_REST_API_Reference/getMFAResponse
Here is a snippet of that example:
{
"isMessageAvailable":true,
"fieldInfo":{
"responseFieldType":"text",
"imageFieldType":"image",
"image":[
66,
77,
58,
116,
0,
0,
0,
0,
0,
0,
54,
0,
0,
0,
40,
0,
0,
0,
-91,
0,
0,
0,
45,
0,
0,
0,
1,
0,
32,
0,
0,
0,
0,
0,
4,
116,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-5,
-1,
0,
-1,
-1,
-1,
0,
-9,
-9,
-9,
0,
-1,
-5,
-1,
0,
-1,
-1,
-1,
0,
-1,
-5,
-1,
0,
-17,
-17,
-17,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-9,
-13,
-9,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-9,
-9,
-9,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-17,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0,
-1,
-1,
-1,
0
],
"minimumLength":-1,
"maximumLength":-1,
"displayString":"Please enter the text shown in the image"
},
"timeOutTime":99900,
"itemId":10014925,
"retry":false
}
NSJSONSerialization will actually convert this to an NSArray of NSNumbers I believe.
I am confused as to how I would convert an NSArray of NSNumbers to image data.
I looked around on google and found examples in PHP, Java and C++, but nothing specifically for Objective-C/Cocoa.
Does anyone know how to do this?

Answer 1

Something like this should work:
NSArray *jsonBytes = ...
char *bytes = malloc(jsonBytes.count);
NSUInteger index = 0;
for (NSNumber *byteNumber in jsonBytes) {
bytes[index++] = [byteNumber charValue];
}
NSData *data = [NSData dataWithBytesNoCopy:bytes
length:jsonBytes.count
freeWhenDone:YES];
//maybe also specify the scale
UIImage *image = [UIImage imageWithData:data];