Since the development of high-brightness blue and green LEDs, the use of outdoor commercial LED displays has been increasing. Because of their high brightness, good visibility, and long-term durability to the weather, LED displays are a preferred technology for outdoor installations such as stadiums, street advertising, and billboards. This paper deals with a large stereoscopic full-color LED display by use of a parallax barrier. We discuss optimization of the viewing area, which depends on LED arrangements. An enlarged viewing area has been demonstrated by using a 3-in-1 chip LED panel that has wider black regions than ordinary LED lamp cluster panels. We have developed a real-time measurement system of a viewer's position and utilized the measurement system for evaluation of performance of the different designs of stereoscopic LED displays, including conventional designs to provide multiple perspective images and designs to eliminate pseudoscopic viewing areas. In order to show real-world images, it is necessary to capture stereo-images, to process them, and to show in real-time. We have developed an active binocular camera and demonstrated the real-time display of stereoscopic movies and real-time control of convergence.