Image in scnview is darker than in other view

Hello developers,

I have a original image that is ordinary one.

and set image in image view like this

imageview.image = UIImage(cgImage: image)

result is this,

and then set same image in scenekit like this

scnview.scene.background.contents =  image

and result is,

I use same image to two othre view, and one in scnview is darker than original one, and I don't know the problem... found in google, who has a same problem, but there is no answer. (https://stackoverflow.com/questions/60679819/adding-uiimageview-to-arscnview-scene-background-causes-saturation-hue-to-be-off)

checked scnview's pixelformat it was bgra8unorm.
What's the problem??