ios - ARKit – 白皮书检测

Question

我想构建一个非常简单的 AR 应用程序，它能够检测周围的一张白色 A4 纸。我认为使用 Apple's image recognition sample project 就足够了以及 A4 纸比例的白色样本图像，但 ARSession 将失败。

One or more reference images have insufficient texture: white_a4, NSLocalizedRecoverySuggestion=One or more images lack sufficient texture and contrast for accurate detection. Image detection works best when an image contains multiple high-contrast regions distributed across its extent.

有没有一种简单的方法可以使用 ARKit 检测纸张？谢谢!

Answer 1

我认为即使 ARKit 3.0 目前还没有准备好检测抽象白纸。

如果你有一张白纸，其角上有一些标记，或者上面有一些文字，或者甚至是放置在特定环境中的白纸(这是一种基于周围环境的检测，而不是基于纸本身) –那么它就有一定的意义。

但是简单的白纸上没有明显的标记，因此 ARKit 不知道它是什么，它的颜色是什么(例如，在房间外面它是冷色调，但在房间里面它是具有暖色调)，对比度是什么(对比度在图像检测中的重要属性)以及它的方向(这主要取决于您的视角)。

Suppose the common sense of image detection is that ARKit detects image, not its absence.

因此，为了连续检测，您不仅需要为 ARKit 提供一张纸，还需要提供其周围的环境。

另外，您可以查看Apple's recommendations使用图像检测技术时:

• Enter the physical size of the image in Xcode as accurately as possible. ARKit relies on this information to determine the distance of the image from the camera. Entering an incorrect physical size will result in an ARImageAnchor that’s the wrong distance from the camera.

• When you add reference images to your asset catalog in Xcode, pay attention to the quality estimation warnings Xcode provides. Images with high contrast work best for image detection.

• Use only images on flat surfaces for detection. If an image to be detected is on a nonplanar surface, like a label on a wine bottle, ARKit might not detect it at all, or might create an image anchor at the wrong location.

• Consider how your image appears under different lighting conditions. If an image is printed on glossy paper or displayed on a device screen, reflections on those surfaces can interfere with detection.

我必须补充一点，您需要一种独特的纹理图案，而不是重复的纹理图案。