找最大色块

def find_max_red_blobs(blobs, img):
    if not blobs:
        print("没有找到任何 blobs")
        return None

    try:
        red_blob = max(blobs, key=lambda b: b.pixels())
        #print("x:%d,y:%d,w:%d,h:%d" % (red_blob.cx(), red_blob.cy(), red_blob.w(), red_blob.h()))
        img.draw_cross(red_blob.cx(),red_blob.cy())
        print("红色像素数量：%d" % red_blob.pixels())
        return red_blob
    except Exception as e:
        print("发生错误: ", e)
        return None