A confused wallpaper is an image with a high number of detected sources and a spatial structure of many point sources. It does not often occur at optical wavelengths, but may be seen in dense star clusters. However, in the near-infrared and far-infrared, a large portion of the sources is obscured by the confusion noise. The confusion noise is typically microJy and mJy, depending on the wavelengths and the source types.
What is a Confused background?
A confused wallpaper is a type of image that has many detected sources and a chaotic spatial structure. While this is not a common phenomenon at optical wavelengths, it can occur in dense star clusters. Further, a source in the far- or mid-IR can be confusing because of cirrus emission. However, such a wallpaper is not the only type of source to be confused. Other types of sources can also confuse a background image.