An erect image, in optics, is one that appears right-side up. It is an image in which directions are the same as those in the object, in contrast to an inverted image. Some telescopes and other devices, such as the camera obscura present an inverted image on the viewing surface. Various means are used to achieve an erect image. A common example of an erect image is the image of a person in a standard plane mirror.
References
Erect image Wikipedia(Text) CC BY-SA