basically the image is bigger than your UIView. when you give UIColor(patternImage: image) it uses 1x size of the image. 
The image we  usually laptops are scaled to window size with its aspect ratio. 

So scale your image to your requirement and then apply it as background image. 

How do I make image-based tiled background for UIView so that it doesn't scale?
What kind of non-technical training course do you suggest for a programmer? Example could be public speaking course, presentation skill, English, business writing, or anything not related to programming or software engineering itself.
