Uiimage to Base64 and back - database

Question

I tri to convert NSData to Base64 to save an UIImage in the database, in a blob, that is located at a remote server.
To parse:
NSData *imagenData = UIImagePNGRepresentation(self.imagen.image);
MetodosComunes *metodos = [[MetodosComunes alloc] init];
NSString *imagenStr = [metodos base64forData:imagenData];
The method base64forData:
-(NSString*)base64forData:(NSData*)theData {
const uint8_t* input = (const uint8_t*)[theData bytes];
NSInteger length = [theData length];
static char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
NSMutableData* data = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
uint8_t* output = (uint8_t*)data.mutableBytes;
NSInteger i;
for (i=0; i < length; i += 3) {
NSInteger value = 0;
NSInteger j;
for (j = i; j < (i + 3); j++) {
value <<= 8;
if (j < length) {
value |= (0xFF & input[j]);
}
}
NSInteger theIndex = (i / 3) * 4;
output[theIndex + 0] = table[(value >> 18) & 0x3F];
output[theIndex + 1] = table[(value >> 12) & 0x3F];
output[theIndex + 2] = (i + 1) < length ? table[(value >> 6) & 0x3F] : '=';
output[theIndex + 3] = (i + 2) < length ? table[(value >> 0) & 0x3F] : '=';
}
return [[[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding] autorelease];
}
Then, i need to show this saved image at the application, and i convert base64 to NSData:
- (NSData *)base64DataFromString: (NSString *)string
{
unsigned long ixtext, lentext;
unsigned char ch, inbuf[4], outbuf[3];
short i, ixinbuf;
Boolean flignore, flendtext = false;
const unsigned char *tempcstring;
NSMutableData *theData;
if (string == nil)
{
return [NSData data];
}
ixtext = 0;
tempcstring = (const unsigned char *)[string UTF8String];
lentext = [string length];
theData = [NSMutableData dataWithCapacity: lentext];
ixinbuf = 0;
while (true)
{
if (ixtext >= lentext)
{
break;
}
ch = tempcstring [ixtext++];
flignore = false;
if ((ch >= 'A') && (ch <= 'Z'))
{
ch = ch - 'A';
}
else if ((ch >= 'a') && (ch <= 'z'))
{
ch = ch - 'a' + 26;
}
else if ((ch >= '0') && (ch <= '9'))
{
ch = ch - '0' + 52;
}
else if (ch == '+')
{
ch = 62;
}
else if (ch == '=')
{
flendtext = true;
}
else if (ch == '/')
{
ch = 63;
}
else
{
flignore = true;
}
if (!flignore)
{
short ctcharsinbuf = 3;
Boolean flbreak = false;
if (flendtext)
{
if (ixinbuf == 0)
{
break;
}
if ((ixinbuf == 1) || (ixinbuf == 2))
{
ctcharsinbuf = 1;
}
else
{
ctcharsinbuf = 2;
}
ixinbuf = 3;
flbreak = true;
}
inbuf [ixinbuf++] = ch;
if (ixinbuf == 4)
{
ixinbuf = 0;
outbuf[0] = (inbuf[0] << 2) | ((inbuf[1] & 0x30) >> 4);
outbuf[1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
outbuf[2] = ((inbuf[2] & 0x03) << 6) | (inbuf[3] & 0x3F);
for (i = 0; i < ctcharsinbuf; i++)
{
[theData appendBytes: &outbuf[i] length: 1];
}
}
if (flbreak)
{
break;
}
}
}
return theData;
}
When i show the image, the image is black. At the console appear this error:
May 16 17:04:13 MacBook-Pro-de-Alejandro.local pantallas[1608] : ImageIO: PNG invalid PNG file: iDOT doesn't point to valid IDAT chunk May 16 17:04:13 MacBook-Pro-de-Alejandro.local pantallas[1608] : ImageIO: PNG Extra compressed data