Question

I am trying to encrypt an image into Base64 String. Please find the required code. I am getting null value as response

fullpath = /Users/srt/Library/Application Support/iPhone Simulator/5.1/Applications//Documents/image.png



UIImage *sImage=[UIImage imageNamed:fullPath];
    [fileManager createFileAtPath:fullPath contents:imageData attributes:nil];
    NSLog(@"image saved");
    NSLog(@"%@",fullPath);
   NSData* data = UIImageJPEGRepresentation(sImage, 1.0f);


    NSString *strEncoded = [self Base64ImageEncode:data];
     NSLog(@"This is the encryption %@ ",strEncoded);

-(NSString *)Base64ImageEncode:(NSData *)data{
    //Point to start of the data and set buffer sizes
    int inLength = [data length];
    int outLength = ((((inLength * 4)/3)/4)*4) + (((inLength * 4)/3)%4 ? 4 : 0);
    const char *inputBuffer = [data bytes];
    char *outputBuffer = malloc(outLength);
    outputBuffer[outLength] = 0;

    //64 digit code
    static char Encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    //start the count
    int cycle = 0;
    int inpos = 0;
    int outpos = 0;
    char temp;

    //Pad the last to bytes, the outbuffer must always be a multiple of 4
    outputBuffer[outLength-1] = '=';
    outputBuffer[outLength-2] = '=';

    /* http://en.wikipedia.org/wiki/Base64
     Text content   M           a           n
     ASCII          77          97          110
     8 Bit pattern  01001101    01100001    01101110

     6 Bit pattern  010011  010110  000101  101110
     Index          19      22      5       46
     Base64-encoded T       W       F       u
     */


    while (inpos < inLength){
        switch (cycle) {
            case 0:
                outputBuffer[outpos++] = Encode[(inputBuffer[inpos]&0xFC)>>2];
                cycle = 1;
                break;
            case 1:
                temp = (inputBuffer[inpos++]&0x03)<<4;
                outputBuffer[outpos] = Encode[temp];
                cycle = 2;
                break;
            case 2:
                outputBuffer[outpos++] = Encode[temp|(inputBuffer[inpos]&0xF0)>> 4];
                temp = (inputBuffer[inpos++]&0x0F)<<2;
                outputBuffer[outpos] = Encode[temp];
                cycle = 3;
                break;
            case 3:
                outputBuffer[outpos++] = Encode[temp|(inputBuffer[inpos]&0xC0)>>6];
                cycle = 4;
                break;
            case 4:
                outputBuffer[outpos++] = Encode[inputBuffer[inpos++]&0x3f];
                cycle = 0;
                break;
            default:
                cycle = 0;
                break;
        }
    }
    NSString *pictemp = [NSString stringWithUTF8String:outputBuffer];
    free(outputBuffer);
    return pictemp;
}

The encoded result is This is the encryption Kindly correct me with my mistake and reason also,if required OR any other better way to do it.

Answer 1

You cannot load image from document directory using the imageNamed: method.
This method is used for loading the image from the application bundle. Where the parameter should be the name of the image.

Like:

UIImage *tempImage = [UIImage imageNamed:@"myImage.png"];

That’s why the image is getting null.

Use imageWithContentsOfFile: method.

UIImage *sImage = [UIImage imageWithContentsOfFile:fullPath];