IOS 给图片添加水印 打印文字

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.加图片

-(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;

}