byte array to uiimageView in ios

Question

My requirement is that a local image will be converted to a byte array and then the byte array is converted back to the image

i have done the image to Byte array conversion but i trying bytearray convert to image and then display on UIIMageView code is no error but Image Converted to byte array but byte array converted io image but image is not display please give me any idea

Here is what I have so far

   UIImage *image = [UIImage imageNamed: @"shopper-home-copy_03.png"];




   //Output
   NSData *data = UIImagePNGRepresentation(image);

    NSUInteger len = data.length;

    uint8_t *bytes = (uint8_t *)[data bytes];

    NSMutableString *result = [NSMutableString stringWithCapacity:len * 3];


    [result appendString:@"["];

    for (NSUInteger i = 0; i < len; i++)
    {
        if (i)
        {

            [result appendString:@","];

        }

        [result appendFormat:@"%d", bytes[i]];
    }

    [result appendString:@"]"];
   NSMutableData *newdata = [NSMutableData new];
    NSScanner *theScanner = [NSScanner scannerWithString: result];
    while ([theScanner isAtEnd] == NO) {
        int a;
        [theScanner scanInt:&a];
        uint8_t b = a;
        [newdata appendBytes:(const void *)&b length:1];
    }

    UIImage *newImage = [UIImage imageWithData:newdata];
    self->imageView = [[UIImageView alloc] initWithImage:newImage];

    imageView.frame = CGRectMake(0, 25 , 150,150);

    [self.view addSubview:self->imageView];

Have a look, http://stackoverflow.com/questions/22316608/how-to-convert-byte-array-to-image-in-ios/22316710#comment33918939_22316710 — kukushi, Mar 12 '14 at 09:09

Avt · Accepted Answer · 2014-03-12T09:41:50.073

1

First of all you should check is Base64 is suitable for you. If you still need your own format try following

NSMutableData *newData = [NSMutableData new];
NSScanner *theScanner = [NSScanner scannerWithString: result];
theScanner.charactersToBeSkipped = [NSCharacterSet characterSetWithCharactersInString:@"[],"];
while ([theScanner isAtEnd] == NO) {
    int a;
    [theScanner scanInt:&a];
    uint8_t b = a;
    [newData appendBytes:(const void *)&b length:1];
}
UIImage *newImage = [UIImage imageWithData:newData];

edited Mar 12 '14 at 09:41

answered Mar 12 '14 at 09:05

Avt

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NSMutableData *data = [NSMutableData new]; this line error – Vasavi Mar 12 '14 at 09:28
Redefinition of 'data' with a different type :'NSMutableData *_string' vs'NSdata *_string' this is error message – Vasavi Mar 12 '14 at 09:34
It is just because you already have `data` variable. I have renamed it with `newData` in the answer. – Avt Mar 12 '14 at 09:36
it's not Showing any error and then it's not Showing Image also please help me – Vasavi Mar 12 '14 at 09:54
I have just checked - everything works. Are you sure you did not forget to copy line `theScanner.charactersToBeSkipped = [NSCharacterSet characterSetWithCharactersInString:@"[],"];` ? I can not find it in code you copy-pasted to question. – Avt Mar 12 '14 at 10:26

score 0 · Answer 2 · answered Mar 12 '14 at 09:14

0

Create an NSData object from the byte array. And then use this

UIImage *image = [UIImage imageWithData:data];

answered Mar 12 '14 at 09:14

Shanti K

2,873
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score 0 · Answer 3 · edited May 23 '17 at 11:43

0

Try this to convert string to bytes array..

first step to convert mutable string to array.

NSArray *strings = [<mutableString> componentsSeparatedByString:@","];

unsigned c = strings.count; // strings is the array instance from the mutable string (separate using ",")
uint8_t *bytes = malloc(sizeof(*bytes) * c);

unsigned i;

for (i = 0; i < c; i++)

{
NSString *str = [strings objectAtIndex:i];

int byte = [str intValue];
bytes[i] = byte;
}

from bytes convert to image is as follows..

NSData *imageData = [NSData dataWithBytesNoCopy:bytes length:c freeWhenDone:YES];
UIImage *image = [UIImage imageWithData:imageData];

reference from Byte Array to NSData

edited May 23 '17 at 11:43

Community

1
1

answered Mar 12 '14 at 09:18

RAJA

1,214
10
13

thanks fro Replay but i using NSMutableString unsigned c = strings.count; NSString *str = [strings objectAtIndex:i]; this 2 lines are Error please help me – Vasavi Mar 12 '14 at 09:22
Raja propetry 'count' not found on Object of type 'NSmutbaleString *' and NO Visible @interface for 'NSMutableString' declares the selecor 'objectAtIndex:' – Vasavi Mar 12 '14 at 09:27
Are you using `NSMutableString`? – Himanshu Joshi Mar 12 '14 at 09:28
@Raja Image is Not display – Vasavi Mar 12 '14 at 10:20

Himanshu Joshi · Answer 4 · 2014-03-12T09:31:33.417

0

Convert byteArray to NSData and then to UIImage

-(UIImage *)convertToImageFromByteArray:(NSMutableString*)mutableStr{

    NSArray *byteArray = [mutableStr componentsSeparatedByString:@","];

    unsigned c = byteArray.count;
    uint8_t *bytes = malloc(sizeof(*bytes) * c);

    unsigned i;
    for (i = 0; i < c; i++)
    {
        NSString *str = [byteArray objectAtIndex:i];
        int byte = [str intValue];
        bytes[i] = (uint8_t)byte;
    }

    NSData *data = [NSData dataWithBytes:bytes length:c];

    return [UIImage imageWithData:data];
}

edited Mar 12 '14 at 09:31

answered Mar 12 '14 at 09:23

Himanshu Joshi

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I want Byte array convert to image – Vasavi Mar 12 '14 at 09:57
You have said that you want to convert `NSMUtableString` – Himanshu Joshi Mar 12 '14 at 09:58
if you want to convert `byteArray` then simply change the function to `-(UIImage *)convertToImageFromByteArray:(NSArray*)byteArray` and remove the line `NSArray *byteArray = [mutableStr componentsSeparatedByString:@","];`. – Himanshu Joshi Mar 12 '14 at 09:59

byte array to uiimageView in ios

4 Answers4