ios - 合并两个旋转和缩放的UIImage

Question

我正在做一个类似这样的应用程序:您加载一张照片，然后将图像放在上面，例如气球等。

当我尝试仅调整大小而将其中之一合并到图像上时，它工作正常。比应有的像素多10像素，但没有问题。

问题是，当您旋转图像[UIImageView]时，它看起来比图像大得多，我尝试分配所有内容，但没有进行任何操作。我离开了代码。希望有人能帮忙。

注意:图像大小位于UIImageView内部，然后乘以主图像的比例

- (UIImage *)mergeImage:(UIImageView *)mainImage withImageView:(UIImageView *)imageView {

    UIImage *temp = imageView.image;
    UIImage *tempMain = mainImage.image;

    CGFloat mainScale = [self imageViewScaleFactor:mainImage];
    CGFloat tempScale = 1/mainScale;
    NSLog(@"%f", tempScale);

    //Rotate UIIMAGE
    UIGraphicsBeginImageContext(temp.size);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGAffineTransform transform = CGAffineTransformIdentity;
    transform = CGAffineTransformTranslate(transform, temp.size.width/2, temp.size.height/2);    
    CGFloat angle = atan2(imageView.transform.b, imageView.transform.a);    
    transform = CGAffineTransformRotate(transform, angle);
    transform = CGAffineTransformScale(transform, 1.0, -1.0);
    CGContextConcatCTM(ctx, transform);
    // Draw the image into the context
    CGContextDrawImage(ctx, CGRectMake(-temp.size.width/2, -temp.size.height/2, temp.size.width, temp.size.height), temp.CGImage);
    // Get an image from the context
    temp = [UIImage imageWithCGImage: CGBitmapContextCreateImage(ctx)];


    NSLog(@"%f %f %f", mainScale, mainImage.frame.size.width, mainImage.frame.size.height);

    UIGraphicsBeginImageContextWithOptions(tempMain.size, NO, 1.0f);

    //Get imageView size & position 
    NSLog(@"%f %f %f %f", imageView.frame.origin.x, imageView.frame.origin.y, imageView.frame.size.width, imageView.frame.size.height);

    CGFloat offsetX = 0;
    CGFloat offsetY = -44;

    if (tempMain.size.height > tempMain.size.width) {
        offsetX = ((tempMain.size.width * mainScale) - 320)/2;
    }else{
        offsetY = ((tempMain.size.height * mainScale) - 416)/2;
        offsetY -= 44;
    }

    CGFloat imageViewX = (imageView.frame.origin.x + offsetX) * tempScale;
    CGFloat imageViewY = (imageView.frame.origin.y + offsetY) * tempScale;
    CGFloat imageViewW = imageView.frame.size.width * tempScale;
    CGFloat imageViewH = imageView.frame.size.height * tempScale;


    CGRect tempRect = CGRectMake(imageViewX, imageViewY, imageViewW, imageViewH);


    [tempMain drawAtPoint:CGPointZero];
    [temp drawInRect:tempRect];

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

谢谢

Answer 1

这是对我有用的解决方案

Merging a previosly rotated by gesture UIImageView with another one. WYS is not WYG

我只是将照片拍摄到主屏幕上，然后将其裁剪为照片的大小，更快，更干净。如果应用程序在正常设备中的视网膜中运行，分辨率还不错。您需要准备该代码才能在视网膜和非视网膜中工作