Go to the page on which you want to insert an image and then, on the ribbon, click the Page tab.
In the Edit group, click the Edit Button.
Click in a blank area of the page.
Back on the ribbon, click the Insert tab.
In the Media group, click the Picture button.
On the menu that appears, click From SharePoint.
In the Select An Asset dialog box, in the pane on the left, select the image that you want to add from the library in which it resides.
Click the Insert button.
Click the Save button.