增强现实是将虚实信息融合的技术，该系统目标是利用普通的网络摄像头，实时地在用户提供的包围在黑色方框中的汉字标志图像上附加相关的媒体信息，有效地扩展和丰富传统的看图识字。为了在复杂的光影下也能稳定地检测出标志，系统利用边缘提取优化了标志检测方法。为了稳定快速地求解摄像机参数，系统首先利用单应性矩阵快速求解出初值，并通过在优化函数中加入自适应的平滑性约束来抑制图像噪声的影响，使得求解的摄像机参数更加精确平滑。实验结果证明了该系统的稳定性和实用性。

Augmented reality is a technique to fuse virtual and real worlds. The proposed augmented reality system aims to use an off-the-shelf web camera, and augments related virtual media information onto the Chinese-character-markers surrounded by black rectangles, which provides a new learning experience for Chinese character. The proposed method enhances the marker detection method with edge extraction, and performs well under complicated shading condition. To reliably solve the camera parameters, the proposed system first uses the homography to estimate the initial values, and then incorporates adaptive smoothness constraint to reduce the image noise. This constraint makes the solved camera parameters very accurate and stable. The experimental results demonstrate the effectiveness and robustness of the proposed system.