I have a 2D marker that has a color scheme of red. I used ARKit's ARReferenceImage to detect images via rear camera. I'm having problems with the marker because it detects similar images but in different color scheme, I think ARKit recognizes only the pattern and disregarding the color.
I already implemented the basic code for image recognition from here
What my goal is to avoid detecting similar markers in different color schemes, I tried to search around but no luck. Thanks in advance.
To recognize similar images with different colour scheme in ARKit or in RealityKit is a bad idea from the very beginning.
At first, please take into consideration that ARReferenceImage is a set. Swift's set is unordered collection of UNIQUE values. If Apple engineers wanted to create ARReferenceImage as array they would do it. But it's a SET in every sense of this word – in images' names and visually.
func referenceImages(inGroupNamed name: String,
bundle: Bundle?) -> Set<ARReferenceImage>?
Secondly, when implementing ARTrackable protocol (remember, ARImageAnchor conforms to ARTrackable), you shouldn't track similar images or repetitive structures as Apple suggests.
@available(iOS 11.3, *)
open class ARImageAnchor : ARAnchor, ARTrackable {
open var referenceImage: ARReferenceImage { get }
@available(iOS 13.0, *)
open var estimatedScaleFactor: CGFloat { get }
}
Watch ARKit WWDC 2018 video (Time 37:40) for details.
Thirdly, iPhone's neural engine perceives ARKit's and RealityKit's reference images in the black-and-white spectrum. I think it's made for two main reasons: one – Luma-contrast is more important than Chroma-contrast, and second – image recognition doesn't depend on environment light color – whether it's yellowish or blueish – the recognition's result should be unaltered.
Do you guess what ARKit sees, looking at three similar images with different colour scheme?
The differences between green and cyan images are subtle.