Get average outer pixel color of image

So I want to get the average color of the outer pixels in an image, to give the background of the div the image is shown in, the same color. So I won't have to make all images the background color myself.

Example: if the image is 100px x 100px, you check the 5 outer pixels at the top of the image, 5 outer pixels of the right side of the image, same for left and bottom. You will get 5 x 100 x 4 pixels, get the colors, check the average and let JS give the div the same background.

So if the average color is #000000, the div BG will be #000000. If average is #FAFAFA, the div BG will be #FAFAFA