一个改进的自适应canny算法，该方法采用改进的开关型中值滤波器对图像做去噪工作，再把整幅图像分割为若干子图像，最后在充分考虑全局以及各子图像的边缘梯度信息后，自适应地生成动态阈值。(The new Canny adaptive method divides image into sub-images,then determinates the thresholds automatically according to the whole image edge information and the sub-images edge information.)