This work is about a survey of the various image fusion methods. The major function of image fusion in multi-focus cameras is to merge data from several pictures of one scenario so as to show just the multifocused picture. The Discrete Cosine Transform or DCT founded techniques of image fusion are more appropriate and time-economic in instantaneous frameworks utilizing DCT founded regulations of motionless picture or video clip. In this work, a proficient method for the combination of multi-focus pictures founded on variance computed in DCT field is introduced. The general aim is to discover the blanks in current literature and proposing an appropriate scheme to diminish the blanks of current methods.

Keywords : Image fusion, Visual Sensor, DCT, PCA.