1. A method for compensating time difference between images, suitable for an electronic apparatus, the method comprising: respectively setting a reference area and a reference area background for each of a plurality of image capturing units; respectively receiving a first input image from each of the image capturing units; respectively checking whether the reference area of each of the first input images is the same as the corresponding reference area background; when the reference area of the first input image received from one of the image capturing units is not the same as the corresponding reference area background, and the reference areas of the first input images received from the other image capturing units are the same as the reference area backgrounds, the other image capturing units continually receive a second input image and respectively accumulate a compensation image number corresponding to each of the other image capturing units; checking the second input image received from each of the other image capturing units to see whether the reference area is the same as the corresponding reference area background; when the reference area of the second input image received from each of the other image capturing units is the same as the corresponding reference area background, continually receiving a third input image and respectively accumulate the compensation image number; and continually performing the checking process until the reference area of each of the third input images received from the other image capturing units is not the same as the corresponding reference area background, and respectively compensating time difference of each of the image capturing units according to the compensation image number corresponding to each of the image capturing units.