通过在线PCA来识别手势，并能对新增手势做一定的增量，很好的实现了增量学习。算法具有效率高，识别率好，速度快等特点，同样适合其他模式识别方面的应用。-The learning method for hand gesture recognition system based on vision is commonly off-line，which results in repeated off-line learning when new hand gestures come． Its real-