iOS图片上加标签或者水印

#import <UIKit/UIKit.h>

@interface UIImage (Text)

- (UIImage*)addText:(NSString*)text1
               XPos:(int)xpos
               YPos:(int)ypos
           fontName:(NSString*)fontName
           fontSize:(CGFloat)fontSize
          fontColor:(UIColor*)fontColor;

@end

#import "UIImage+Text.h"

@implementation UIImage (Text)

- (UIImage*)addText:(NSString*)text1
               XPos:(int)xpos
               YPos:(int)ypos
           fontName:(NSString*)fontName
           fontSize:(CGFloat)fontSize
          fontColor:(UIColor*)fontColor {
    
    int w = self.size.width;
    int h = self.size.height;
	
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
    
    CGContextDrawImage(context, CGRectMake(0, 0, w, h), self.CGImage);
    CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1);
	
    char *txt = (char*)[text1 cStringUsingEncoding:NSUTF8StringEncoding];
    char *font = (char*)[fontName cStringUsingEncoding:NSUTF8StringEncoding];
    
    CGContextSelectFont(context, font, fontSize, kCGEncodingMacRoman);
    CGContextSetTextDrawingMode(context, kCGTextFill);
    CGContextSetFillColorWithColor(context, fontColor.CGColor);
    CGContextShowTextAtPoint(context, xpos, ypos, txt, strlen(txt));
    
	CGImageRef imageRef = CGBitmapContextCreateImage(context);
	CGContextSetAllowsAntialiasing(context, YES);
	
	UIImage *result = [UIImage imageWithCGImage:imageRef];
	
	CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
	
    return result;
}

@end

 UIImage *img = [UIImage imageNamed:@"image.jpg"];
    image.image = [img addText:text.text
                          XPos:80
                          YPos:300
                      fontName:@"Georgia-Bold"
                      fontSize:46.0
                     fontColor:[UIColor whiteColor]];