ios - 像视频一样显示一系列图像？

Question

我正在 iOS 上试验图像处理算法。我有一个带有图片的 Assets 目录 test_frame1 ... test_frame100 (等等)我做一些处理。

除其他外，我需要按顺序显示图像，就好像它们是视频的帧一样。

我首先想到的是顺序更改 UIImage 的图像。经过几毫秒的延迟。我正在异步执行此操作。这是代码:

    let imageShowQueue = dispatch_queue_create("com.grigoryptashko.ImageShowQueue",
        DISPATCH_QUEUE_SERIAL)
    let frameShowDelay = Int64(0.2 * Double(NSEC_PER_SEC)) // show images with 200 ms delay, but it doesn't actually work this way
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
        var dTime = dispatch_time(DISPATCH_TIME_NOW, frameShowDelay)
        for i in 1...1000 {
            dispatch_after(dTime, self.imageShowQueue) {
                dispatch_async(dispatch_get_main_queue()) {
                    NSLog("test_frame\((i % 100) + 1)")
                    self.imgView.image = UIImage(named: "test_frame\((i % 100) + 1)")
                    self.imgView.setNeedsDisplay()
                }
            }

            dTime = dispatch_time(dTime, frameShowDelay)
        }
    }

它确实有效，但 FPS 很快变得太低，例如 1 FPS 甚至更慢。有没有其他方法可以实现这一目标？

也许，有一些我不知道的方法。例如，最近我了解到 Accelerate框架和 Apple Metal . Ant 其他想法？

Answer 1

听起来你想要一个基于图像的动画。这是你要做的:

在您的 viewDidLoad

self.<name of the UIImageView you want to animate>.animationImages = [[NSArray alloc] initWithObjects: [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],
                                     [UIImage imageNamed:@"Image Name"],nil];
                      /* Do this until you have all the images in the array */
self.<name of the UIImageView you want to animate>.animationDuration = 1.0f;
self.<name of the UIImageView you want to animate>.animationRepeatCount = 1;

然后你使用 [<name of the UIImageView you want to animate> startAnimating];你想让动画开始吗？ animationDuration 的号码和 animationRepeatCount可以更改为您希望它们成为的值。 Here是 Apple Docs 的链接。

对于 Swift 开发:

<name of the UIImageView you want to animate>.animationImages = [
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!,
                                         UIImage(named: "Image Name")!
                                       ]
                          /* Do this until you have all the images in the array */
<name of the UIImageView you want to animate>.animationDuration = 1.0
<name of the UIImageView you want to animate>.animationRepeatCount = 1