如何合并iPhone SDK中Objective-C中的两个UIImage对象

Question

我正在开发一个iPhone应用程序，我想合并两个UIImage（leftImage和rightImage）。任何人都可以建议如何做到这一点，而没有在他们之间的线？

我目前这样做：

- (UIImage*)mergeImage:(UIImage*)first withImage:(UIImage*)second 
{ 
    // get size of the first image 
    CGImageRef firstImageRef = first.CGImage; 
    CGFloat firstWidth = CGImageGetWidth(firstImageRef); 
    CGFloat firstHeight = CGImageGetHeight(firstImageRef); 

    // get size of the second image 
    CGImageRef secondImageRef = second.CGImage; 
    CGFloat secondWidth = CGImageGetWidth(secondImageRef); 
    CGFloat secondHeight = CGImageGetHeight(secondImageRef); 

    // build merged size 
    CGSize mergedSize = CGSizeMake((firstWidth+secondWidth), MAX(firstHeight, secondHeight)); 

    // capture image context ref 
    UIGraphicsBeginImageContext(mergedSize); 

    //Draw images onto the context 
    [first drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)]; 
    //[second drawInRect:CGRectMake(firstWidth, 0, secondWidth, secondHeight)]; 
    [second drawInRect:CGRectMake(firstWidth, 0, secondWidth, secondHeight) blendMode:kCGBlendModeNormal alpha:1.0]; 

    // assign context to new UIImage 
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 

    // end context 
    UIGraphicsEndImageContext(); 

    return newImage; 

} 

但它创造了两个图像之间的小行。我不想要这个分隔符，就像Splitcam那样。

我该怎么做？

Answer 1

只有边缘重叠一个像素。

[second drawInRect:CGRectMake(firstWidth-1, 0, secondWidth, secondHeight) 
    blendMode:kCGBlendModeNormal alpha:1.0];