Nowadays high definition imaging is an important issue in satellite projects and cameras. Several countries are trying to implement better imaging device for their applications, such as satellite applications. For example, forecasting, army, forests and etc. In this book a brief discussion is presented for imaging device and then a method is used for reducing the fixed pattern noise (FPN) in image detector. The method that is presented in the following uses a column shifting technique to correct the fixed pattern noise in an image sensor. FPN is an important parameter in imaging devices such as CCD or CMOS. These imaging sensors have widespread applications, such as star trackers, visible and IR imaging devices. Therefore the precision improvement is an important factor in their performance. In addition, the block diagram structure of imaging detector is fully studied in chapter 1 to 3 and then a method has been presented to reduce the FPN noise.