openmv形状识别代码

以下是一个基于OpenMV的色块识别的图形形状识别代码的示例：

import sensor, image

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)

while(True):
    img = sensor.snapshot()
    for blob in img.find_blobs([(30, 100, -128, -10, -10, 10)], pixels_threshold=200, area_threshold=200):
        if blob.roundness() > 0.8:
            img.draw_rectangle(blob.rect())
            img.draw_cross(blob.cx(), blob.cy())
            print("圆形")
        elif blob.roundness() < 0.4:
            img.draw_rectangle(blob.rect())
            img.draw_cross(blob.cx(), blob.cy())
            print("矩形")
        else:
            img.draw_rectangle(blob.rect())
            img.draw_cross(blob.cx(), blob.cy())
            print("三角形")

这段代码使用了OpenMV的`find_blobs()`函数来识别色块，并根据色块的圆度（roundness）来判断形状。如果圆度大于0.8，则判断为圆形；如果圆度小于0.4，则判断为矩形；否则判断为三角形。代码中还使用了`draw_rectangle()`和`draw_cross()`函数来在图像上绘制识别结果。