在iphone中以编程方式将两个图像合并到一个图像上

Question

您好我正在开发需要合并两个图像的应用程序,我的图像大小是320*240通过合并两个图像我希望大小为320*480.我怎么能这样做呢？以下是图片

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Answer 1

刚试过这个,根据您正在使用的图像的大小创建您的上下文并将它们相互叠加(这假设它们的宽度相同):

UIImage *image1 = [UIImage imageNamed:@"image1.png"];
UIImage *image2 = [UIImage imageNamed:@"image2.png"];

CGSize size = CGSizeMake(image1.size.width, image1.size.height + image2.size.height);

UIGraphicsBeginImageContext(size);

[image1 drawInRect:CGRectMake(0,0,size.width, image1.size.height)];
[image2 drawInRect:CGRectMake(0,image1.size.height,size.width, image2.size.height)];

UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

//Add image to view
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, finalImage.size.width, finalImage.size.height)];
imageView.image = finalImage;
[self.view addSubview:imageView];

Answer 2

要避免降低图像质量,请使用UIGraphicsBeginImageContextWithOptions.

如果指定值0.0,则比例因子将设置为设备主屏幕的比例因子.

UIImage *image1 = [UIImage imageNamed:@"image1.png"];
UIImage *image2 = [UIImage imageNamed:@"image2.png"];

CGSize size = CGSizeMake(image1.size.width, image1.size.height + image2.size.height);

UIGraphicsBeginImageContextWithOptions(size, false, 0.0) // Use this call

[image1 drawInRect:CGRectMake(0,0,size.width, image1.size.height)];
[image2 drawInRect:CGRectMake(0,image1.size.height,size.width, image2.size.height)];

UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

//Add image to view
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, finalImage.size.width, finalImage.size.height)];
imageView.image = finalImage;
[self.view addSubview:imageView];

Answer 3

Swift版本

func getMixedImg(image1: UIImage, image2: UIImage) -> UIImage {

    var size = CGSizeMake(image1.size.width, image1.size.height + image2.size.height)

    UIGraphicsBeginImageContext(size)

    image1.drawInRect(CGRectMake(0,0,size.width, image1.size.height))
    image2.drawInRect(CGRectMake(0,image1.size.height,size.width, image2.size.height))
    var finalImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return finalImage
}

你会得到你的图像来调用这个函数:

var myimage1 = UIImage(named: "image1.png")
var myimage2 = UIImage(named: "image2.png")

var finalMixedImage = getMixedImg(myimage1!, image2: myimage2!)