像视频一样显示一系列图像?

Display a sequence of images like a video?

我正在 iOS 上试验图像处理算法。我有一个资产目录,其中包含图像 test_frame1 ... test_frame100(等等),我对其进行了一些处理。

除其他外,我需要按顺序显示图像,就好像它们是视频帧一样。

我首先想到的是在延迟几毫秒后按顺序更改 UIImage 的图像。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。还有其他方法可以实现吗?

也许,有一些我不知道的方法。比如最近学习了Accelerate框架和Apple Metal。还有其他想法吗?

试试这个,更改数组中的图像并编译项目,在这部分设置de时间间隔

animationImageView.animationDuration = 0.5;

http://www.appcoda.com/ios-programming-animation-uiimageview/

听起来您想要一个基于图像的动画。这是你要做的:

在你的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]; 你想要动画开始。 animationDurationanimationRepeatCount 的数字可以更改为您想要的值。 Here 是 link Apple 文档。

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

有一种更直接的方法,即在 UIImage 上使用 animatedImageNamed:。看看这个:

UIImage *animatingImage = [UIImage animatedImageNamed:@"test_frame_" duration:1.0];
UIImageView *anImageView = [[UIImageView alloc] initWithImage:animatingImage];