The pictures in different directions, locations and depths of focus are obtained using the method of computational imaging to satisfy the different requirements and to achieve the function of taking the picture before focusing the camera, and overcoming the drawbacks of mechanical focusing in traditional camera. However, its image quality is lower than the traditional camera because its resolution is restricted by the number of microlens. The high resolution digital autofocus method is proposed, that is extracting the sub aperture pictures firstly, and then doubling the resolution of every sub aperature pictures by the method of the combination of wavelet transformation and interpolation. So, the sub aperature picture array with high resolution can be formed. The refocus processing on this array by Fourier slice transformation is done, and the processed results show that the definition and resolution of the refocused images increase greatly.