iOS-合并两个不同大小的图像

Question

我面临以下问题：由于合并，我必须合并两个图像A和B以创建新图像C。

我已经知道如何合并两个图像，但是在这种情况下，我的目标有所不同。

我希望图像A将作为图像B的背景。

例如，如果图像A的尺寸为500x500，图像B的尺寸为460x460，我希望图像C（合并的图像结果）为500x500，图像B（ 460x460）居中。

在此先感谢您的帮助或建议

Answer 1

这是我在应用程序中所做的，但是没有使用UIImageView：UIImage *bottomImage = [UIImage imageNamed:@"bottom.png"]; //background imageUIImage *image       = [UIImage imageNamed:@"top.png"]; //foreground imageCGSize newSize = CGSizeMake(width, height);UIGraphicsBeginImageContext( newSize );// Use existing opacity as is[bottomImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];// Apply supplied opacity if applicable[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height) blendMode:kCGBlendModeNormal alpha:0.8];UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();如果图像已经具有不透明度，则无需进行设置（如在bottomImage中），否则可以进行设置（与图像一样）。在这之后UIImage创建，那么你可以将它嵌入到你的UIImageView更新：感谢Ahmet AkkoK-对于Swift（2.2）用户，混合模式宏已更改。CGBlendMode .kCGBlendModeNormal被替换为CGBlendMode.Normal

Answer 2

嘿，我得到了多张图像，并添加了具有不同前景的相同背景。UIImage *bottomImage = [UIImage imageNamed:@"photo 2.JPG"]; //background imageUIImage *image       = [UIImage imageNamed:@"photo 3.JPG"]; //foreground imageUIImage *image1      = [UIImage imageNamed:@"photo 4.JPG"]; //foreground imageUIImage *image2      = [UIImage imageNamed:@"photo 5.JPG"]; //foreground imageCGSize newSize = CGSizeMake(320, 480);UIGraphicsBeginImageContext( newSize );// Use existing opacity as is[bottomImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];// Apply supplied opacity if applicable[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height) blendMode:kCGBlendModeNormal alpha:0.4];[image1 drawInRect:CGRectMake(0,0,newSize.width,newSize.height) blendMode:kCGBlendModeNormal alpha:0.3];[image2 drawInRect:CGRectMake(0,0,newSize.width,newSize.height) blendMode:kCGBlendModeNormal alpha:0.2];UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();resultView = [[UIImageView alloc] initWithImage:newImage];resultView.frame = CGRectMake(0, 0,320,460);[self.view addSubview:resultView];

Answer 3

刚刚为想要使用Srikar Appal答案的用户提供了快速粘贴功能。（如果背景图片和前景图片的大小不同）- (UIImage *) mergeImages:(NSString *)bgImageFileName foreGround:(NSString *)fgImageFileName  {    UIImage *bottomImage = [UIImage imageNamed:bgImageFileName]; //background image    UIImage *image       = [UIImage imageNamed:fgImageFileName]; //foreground image    CGSize newSize = CGSizeMake(bottomImage.size.width, bottomImage.size.height);    UIGraphicsBeginImageContext(newSize);    // Use existing opacity as is    [bottomImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];    // Apply supplied opacity if applicable    // Change xPos, yPos if applicable    [image drawInRect:CGRectMake(11,11,image.size.width,image.size.height) blendMode:kCGBlendModeNormal alpha:1.0];    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return newImage;}