CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetLineWidth(context, 1.0);
CGContextSelectFont(context, "Helvetica", 20, kCGEncodingMacRoman);
CGContextSetTextDrawingMode(context, kCGTextFill);

CGPoint center = self.center;

UIFont* font = [UIFont fontWithName:@"Geneva" size:12.0];
[@"Some text" drawAtPoint:center withFont:font];

CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);

NSString *text = @"Some text";
CGPoint center = CGPointMake(100, 200);
UIFont *font = [UIFont systemFontOfSize:14];

CGSize stringSize = [text sizeWithFont:font];
CGRect stringRect = CGRectMake(center.x-stringSize.width/2, center.y-stringSize.height/2, stringSize.width, stringSize.height);

[[UIColor blackColor] set];
CGContextFillRect(context, stringRect);

[[UIColor whiteColor] set];
[text drawInRect:stringRect withFont:font];

CGContextShowTextAtPoint (context, center.x, center.y, "Some text", strlen("Some text"));

-(UIImage *)addText:(UIImage *)img text:(NSString *)text
{
int w = img.size.width;
int h = img.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
CGContextSetTextMatrix(context, CGAffineTransformIdentity);

// Create a path which bounds the area where you will be drawing text.
// The path need not be rectangular.
CGMutablePathRef path = CGPathCreateMutable();

float fontsize = 150;
NSString *fontName = @"Helvetica";
UIFont *ufont = [UIFont fontWithName:fontName size:fontsize];
NSDictionary *textAttributes = @{NSFontAttributeName:ufont
                                 };
CGSize stringSize = [text sizeWithAttributes:textAttributes];
// In this simple example, initialize a rectangular path.
CGRect bounds = CGRectMake(10.0, 10.0, stringSize.width+20, stringSize.height+50);

CGContextSetFillColorWithColor(context, [UIColor colorWithRed:1 green:1 blue:1 alpha:.3].CGColor);
CGContextFillRect(context, bounds);

CGPathAddRect(path, NULL, bounds );

// Initialize a string.
CFStringRef textString = (__bridge CFStringRef)(text);

// Create a mutable attributed string with a max length of 0.
// The max length is a hint as to how much internal storage to reserve.
// 0 means no hint.
CFMutableAttributedStringRef attrString =
CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);

// Copy the textString into the newly created attrString
CFAttributedStringReplaceString (attrString, CFRangeMake(0, 0),
                                 textString);

// Create a color that will be added as an attribute to the attrString.
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat components[] = { 1.0, 0.0, 0.0, 0.8 };
CGColorRef red = CGColorCreate(rgbColorSpace, components);
CGColorSpaceRelease(rgbColorSpace);

CTFontRef font = CTFontCreateWithName((CFStringRef)fontName, fontsize, nil);
CFAttributedStringSetAttribute(attrString,CFRangeMake(0, [text length]),kCTFontAttributeName,font);

// Set the color of the first 12 chars to red.
CFAttributedStringSetAttribute(attrString, CFRangeMake(0, [text length]),
                               kCTForegroundColorAttributeName, red);

// Create the framesetter with the attributed string.
CTFramesetterRef framesetter =
CTFramesetterCreateWithAttributedString(attrString);
CFRelease(attrString);

// Create a frame.
CTFrameRef frame = CTFramesetterCreateFrame(framesetter,
                                            CFRangeMake(0, 0), path, NULL);

// Draw the specified frame in the given context.
CTFrameDraw(frame, context);

// Release the objects we used.
CFRelease(frame);
CFRelease(path);
CFRelease(framesetter);

CFRelease(font);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);

CGContextRelease(context);
CGColorSpaceRelease(colorSpace);

UIImage *result = [UIImage imageWithCGImage:imageMasked];
CGImageRelease(imageMasked);
return result;
}