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ios 给图片上加水印的方法

ios 给图片上加水印的方法

作者: 清蘂翅膀的技术 | 来源:发表于2017-05-16 13:48 被阅读99次

    分享类型:应用开发相关

    ios图片加水印或文字

    详情可见附件,我亲自测试了一下,发现原来的方法确实存在诸多问题,重新写了一下,大家随意取用,有问题再交流

    1.加文字

    - (UIImage *)imageWithLogoText:(UIImage *)img text:(NSString*)text1

    {

    /////注:此为后来更改,用于显示中文。zyq,2013-5-8

    CGSize size = CGSizeMake(200, img.size.height);//设置上下文(画布)大小

    UIGraphicsBeginImageContext(size);//创建一个基于位图的上下文(context),并将其设置为当前上下文

    CGContextRef contextRef = UIGraphicsGetCurrentContext();//获取当前上下文

    CGContextTranslateCTM(contextRef, 0, img.size.height);//画布的高度

    CGContextScaleCTM(contextRef, 1.0, -1.0);//画布翻转

    CGContextDrawImage(contextRef, CGRectMake(0, 0, img.size.width, img.size.height), [img CGImage]);//在上下文种画当前图片

    [[UIColor redColor] set];//上下文种的文字属性

    CGContextTranslateCTM(contextRef, 0, img.size.height);

    CGContextScaleCTM(contextRef, 1.0, -1.0);

    UIFont *font = [UIFont boldSystemFontOfSize:16];

    [text1 drawInRect:CGRectMake(0, 0, 200, 80) withFont:font];//此处设置文字显示的位置

    UIImage *targetimg =UIGraphicsGetImageFromCurrentImageContext();//从当前上下文种获取图片

    UIGraphicsEndImageContext();//移除栈顶的基于当前位图的图形上下文。

    returntargetimg;

    //注:此为原来,不能显示中文。无用。

    //get image width and height

    intw = img.size.width;

    inth = 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:NSUnicodeStringEncoding];

    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.新的添加文字水印的方法一

    #pragma mark -也是文字水印

    - (UIImage *) imageWithStringWaterMark:(NSString*)markString inRect:(CGRect)rect color:(UIColor *)color font:(UIFont *)font

    {

    #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 40000

    if([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)

    {

    UIGraphicsBeginImageContextWithOptions([selfsize],NO, 0.0);// 0.0 for scale means "scale for device's main screen".

    }

    #else

    if([[[UIDevice currentDevice] systemVersion] floatValue] < 4.0)

    {

    UIGraphicsBeginImageContext([selfsize]);

    }

    #endif

    //原图

    [selfdrawInRect:CGRectMake(0, 0,self.size.width,self.size.height)];

    //文字颜色

    [color set];

    //水印文字

    [markString drawInRect:rect withFont:font];

    UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    returnnewPic;

    }

    3.还是添加文字水印方法二

    #pragma mark -还是文字水印

    - (UIImage *) imageWithStringWaterMark:(NSString*)markString atPoint:(CGPoint)point color:(UIColor *)color font:(UIFont *)font

    {

    #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 40000

    if([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)

    {

    UIGraphicsBeginImageContextWithOptions([selfsize],NO, 0.0);// 0.0 for scale means "scale for device's main screen".

    }

    #else

    if([[[UIDevice currentDevice] systemVersion] floatValue] < 4.0)

    {

    UIGraphicsBeginImageContext([selfsize]);

    }

    #endif

    //原图

    [selfdrawInRect:CGRectMake(0, 0,self.size.width,self.size.height)];

    //文字颜色

    [color set];

    //水印文字

    [markString drawAtPoint:point withFont:font];

    UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    returnnewPic;

    }

    4.加图片

    #pragma mark - 加图片水印

    -(UIImage *)imageWithLogoImage:(UIImage *)img logo:(UIImage *)logo

    {

    //get image width and height

    intw = img.size.width;

    inth = img.size.height;

    intlogoWidth = logo.size.width;

    intlogoHeight = 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]);

    }

    5.新的添加图片水印的方法

    #pragma mark -还是图片水印

    - (UIImage *) imageWithWaterMask:(UIImage*)mask inRect:(CGRect)rect

    {

    #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 40000

    if([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)

    {

    UIGraphicsBeginImageContextWithOptions([selfsize],NO, 0.0);// 0.0 for scale means "scale for device's main screen".

    }

    #else

    if([[[UIDevice currentDevice] systemVersion] floatValue] < 4.0)

    {

    UIGraphicsBeginImageContext([selfsize]);

    }

    #endif

    //原图

    [selfdrawInRect:CGRectMake(0, 0,self.size.width,self.size.height)];

    //水印图

    [mask drawInRect:rect];

    UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    returnnewPic;

    }

    6 .加半透明的水印

    //加半透明的水印

    -(UIImage *)imageWithTransImage:(UIImage *)useImage addtransparentImage:(UIImage *)transparentimg

    {

    UIGraphicsBeginImageContext(useImage.size);

    [useImage drawInRect:CGRectMake(0, 0, useImage.size.width, useImage.size.height)];

    [transparentimg drawInRect:CGRectMake(0, useImage.size.height-transparentimg.size.height, transparentimg.size.width, transparentimg.size.height) blendMode:kCGBlendModeOverlay alpha:0.4f];

    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    returnresultingImage;

    }

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