ios圖片加浮水印或文字

1.加文字

-(UIImage *)addText:(UIImage *)img text:(NSString *)text1 {          //get image width and height          int w = img.size.width;         int h = img.size.height;         CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();         //create a graphic context with CGBitmapContextCreate         CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);        CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);         CGContextSetRGBFillColor(context, 0.0, 1.0, 1.0, 1);         char* text = (char *)[text1 cStringUsingEncoding:NSASCIIStringEncoding];         CGContextSelectFont(context, "Georgia", 30, kCGEncodingMacRoman);         CGContextSetTextDrawingMode(context, kCGTextFill);         CGContextSetRGBFillColor(context, 255, 0, 0, 1);         CGContextShowTextAtPoint(context, w/2-strlen(text)*5, h/2, text, strlen(text));         //Create image ref from the context         CGImageRef imageMasked = CGBitmapContextCreateImage(context);         CGContextRelease(context);         CGColorSpaceRelease(colorSpace);         return [UIImage imageWithCGImage:imageMasked]; }

 

2.加圖片

-(UIImage *)addImageLogo:(UIImage *)img text:(UIImage *)logo {        //get image width and height         int w = img.size.width;         int h = img.size.height;        int logoWidth = logo.size.width;         int logoHeight = logo.size.height;         CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();               //create a graphic context with CGBitmapContextCreate         CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);         CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);         CGContextDrawImage(context, CGRectMake(w-logoWidth, 0, logoWidth, logoHeight), [logo CGImage]);         CGImageRef imageMasked = CGBitmapContextCreateImage(context);         CGContextRelease(context);         CGColorSpaceRelease(colorSpace);         return [UIImage imageWithCGImage:imageMasked];         //  CGContextDrawImage(contextRef, CGRectMake(100, 50, 200, 80), [smallImg CGImage]); }

 

 

 

3.加半透明的浮水印

 

- (UIImage *)addImage:(UIImage *)useImage addImage1:(UIImage *)addImage1{           UIGraphicsBeginImageContext(useImage.size);                [useImage drawInRect:CGRectMake(0, 0, useImage.size.width, useImage.size.height)];               [addImage1 drawInRect:CGRectMake(0, useImage.size.height-addImage1.size.height, addImage1.size.width, addImage1.size.height)];             UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();          UIGraphicsEndImageContext();               return resultingImage;   }
http://hi.baidu.com/peter_wwj/item/179cbe060c570e873c42e298