How to show image from the Hex string [iphone]? - iphone

Question

I have such Hex code 89504e470d0a1a0a0000000d49484452000001000000010008060000005c72a8
now this hex code is the code of some image . that I know , now I want to show that image in a imageView . I dont know how to do it because when I am converting this Hex into NSData and trying yo convert that data into image view and when I show that Image . the image is not being shown.
can anybody tell me how to do this?
// This is the first part i.e. image to hex conversion
UIImage *img = [UIImage imageNamed:#"image.png"];
NSData *data1 = UIImagePNGRepresentation(img);
// NSLog(#"data is %#",data1);
const unsigned *tokenBytes = [data1 bytes];
NSString *hexToken = [NSString stringWithFormat:#"%08x%08x%08x%08x%08x%08x%08x%08x",
ntohl(tokenBytes[0]), ntohl(tokenBytes[1]), ntohl(tokenBytes[2]),
ntohl(tokenBytes[3]), ntohl(tokenBytes[4]), ntohl(tokenBytes[5]),
ntohl(tokenBytes[6]), ntohl(tokenBytes[7])];
NSLog(#"hexToken is %#",hexToken);

Answer 1

If I correctly understand your question, UIImage *image = [UIImage imageWithData:data]; is what you need.
Your NSData to hex conversion is incorrect, you're only taking first 8 bytes as hex token; use following code instead:
- (NSString*)stringWithHexBytes:(NSData *) data {
static const char hexdigits[] = "0123456789ABCDEF";
const size_t numBytes = [data length];
const unsigned char* bytes = [data bytes];
char *strbuf = (char *)malloc(numBytes * 2 + 1);
char *hex = strbuf;
NSString *hexBytes = nil;
for (int i = 0; i<numBytes; ++i) {
const unsigned char c = *bytes++;
*hex++ = hexdigits[(c >> 4) & 0xF];
*hex++ = hexdigits[(c ) & 0xF];
}
*hex = 0;
hexBytes = [NSString stringWithUTF8String:strbuf];
free(strbuf);
return hexBytes;
}
Converting hex string back to NSData:
- (NSData *) hexStringToData:(NSString *) hexString
{
unsigned char whole_byte;
NSMutableData *returnData= [[NSMutableData alloc] init];
char byte_chars[3] = {'\0','\0','\0'};
int i;
for (i=0; i < 8; i++) {
byte_chars[0] = [hexString characterAtIndex:i*2];
byte_chars[1] = [hexString characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, 16);
[returnData appendBytes:&whole_byte length:1];
}
return (NSData *) [returnData autorelease];
}