## 1 Introduction  
Digital image correlation (DIC) technology was proposed in the 1980s [1; 2]. As a robust, noncontact, full-field, and high-precision measurement method, this technology is not sensitive to the measurement environment. Thus, this method has been successfully applied to measure displacement and strain in most cases. The DIC method, especially 3D-DIC, has been extended to numerous research fields by researchers [3; 4; 5; 6]. Therefore, DIC has become an important method in the field of experimental mechanics [7; 8; 9; 10]. Traditional 3D-DIC technology obtains images by using two black and white charge-coupled devices (CCDs) or complementary metal oxide semiconductor (CMOS) cameras. A dual-camera system meets the measurement requirements in most cases. However, due to limitations in the field of view, it is difficult to obtain satisfactory results by using a dual-camera system if a multi-angle analysis is required. Therefore, researchers use multiple cameras to perform DIC measurements. The multi-camera system provides an obvious advantage over the traditional dual-camera system, in that it can cover a large area of measurement and thereby expand the measurement range DIC offers. In addition, for measurement areas with complex profiles, the multi-camera system can effectively reduce errors. However, DIC images are always obtainedusing expensive industrial cameras. For the dual- and multi-camera system, a trigger device must be added in the system in order to meet the required image acquisition synchronization. However, all these factors increase the measurement cost. In recent years, researchers have proposed different methods for 3D-DIC measurement using a single camera. These methods can be mainly divided into two categories. The first divides the camera CCD into two parts, wherein the images of two different angles of the object are presented in two parts of the CCD with the aid of the designed optical path. [PERSON] proposed a four-mirror adapter-assisted single-camera 3D-DIC system to measure full-field out-of-plane displacement histories at high frame rates [11]. [PERSON] used a compact system of a biprism and a camera to perform stereo-DIC measurement [12]. [PERSON] used two planar mirrors and a low-frame-rate camera to measure 3D vibration [13], which is also an interesting application of 3D-DIC measurement using a single camera. This method can also be used with the aid of transmission diffraction grating [14; 15]. The second category uses a color camera, which allows different color channels to record images from different perspectives. [PERSON] and [PERSON] used a 3 CCD color camera to perform 3D-DIC measurement [16; 17]. The approaches presented in these two papers are very similar; the only difference is that [PERSON]'s system has one more mirror than [PERSON]'s system to avoid image flipping. [PERSON] proposed using a single high-speed color CMOS camera to perform high-speed 3D-DIC measurements without an additional triggering device [18]. [PERSON] used a dichroic filter to replace the beam splitter and color filters [19]. This method has considerable advantages, such as simple optical paths, a system requirement of only one color camera, two mirrors, and a cube prism. Another remarkable advantage of this method is that it does not reduce image resolution, which brings the accuracy of the measurements closer to that offered by the traditional dual camera DIC system. [PERSON] used two beam splitters and three mirrors to perform multi-perspective DIC measurement [20], thereby effectively using the three channels of the 3 CCD camera despite its complexity. In this study, we propose a compact setup by using a cross dichroic prism to perform multi-perspective DIC measurements. The images from three different view angles are obtained by the three channels of the 3 CCD color camera through two mirrors and the cross dichroic prism.