find_apriltags

# AprilTags Example
#
# This example shows the power of the CanMV Cam to detect April Tags.

from media.camera import *
from media.display import *
from media.media import *
import time, math, os, gc, sys

DISPLAY_WIDTH = ALIGN_UP(1920, 16)
DISPLAY_HEIGHT = 1080
SCALE = 4
DETECT_WIDTH = DISPLAY_WIDTH // SCALE
DETECT_HEIGHT = DISPLAY_HEIGHT // SCALE

# Note! Unlike find_qrcodes the find_apriltags method does not need lens correction on the image to work.

# The apriltag code supports up to 6 tag families which can be processed at the same time.
# Returned tag objects will have their tag family and id within the tag family.

tag_families = 0
tag_families |= image.TAG16H5 # comment out to disable this family
tag_families |= image.TAG25H7 # comment out to disable this family
tag_families |= image.TAG25H9 # comment out to disable this family
tag_families |= image.TAG36H10 # comment out to disable this family
tag_families |= image.TAG36H11 # comment out to disable this family (default family)
tag_families |= image.ARTOOLKIT # comment out to disable this family

# What's the difference between tag families? Well, for example, the TAG16H5 family is effectively
# a 4x4 square tag. So, this means it can be seen at a longer distance than a TAG36H11 tag which
# is a 6x6 square tag. However, the lower H value (H5 versus H11) means that the false positve
# rate for the 4x4 tag is much, much, much, higher than the 6x6 tag. So, unless you have a
# reason to use the other tags families just use TAG36H11 which is the default family.

def family_name(tag):
    if(tag.family() == image.TAG16H5):
        return "TAG16H5"
    if(tag.family() == image.TAG25H7):
        return "TAG25H7"
    if(tag.family() == image.TAG25H9):
        return "TAG25H9"
    if(tag.family() == image.TAG36H10):
        return "TAG36H10"
    if(tag.family() == image.TAG36H11):
        return "TAG36H11"
    if(tag.family() == image.ARTOOLKIT):
        return "ARTOOLKIT"

def camera_init():
    # use hdmi for display
    display.init(LT9611_1920X1080_30FPS)
    # config vb for osd layer
    config = k_vb_config()
    config.max_pool_cnt = 1
    config.comm_pool[0].blk_size = 4*DISPLAY_WIDTH*DISPLAY_HEIGHT
    config.comm_pool[0].blk_cnt = 1
    config.comm_pool[0].mode = VB_REMAP_MODE_NOCACHE
    # meida buffer config
    media.buffer_config(config)
    # init default sensor
    camera.sensor_init(CAM_DEV_ID_0, CAM_DEFAULT_SENSOR)
    # set chn0 output size
    camera.set_outsize(CAM_DEV_ID_0, CAM_CHN_ID_0, DISPLAY_WIDTH, DISPLAY_HEIGHT)
    # set chn0 output format
    camera.set_outfmt(CAM_DEV_ID_0, CAM_CHN_ID_0, PIXEL_FORMAT_YUV_SEMIPLANAR_420)
    # create meida source device
    globals()["meida_source"] = media_device(CAMERA_MOD_ID, CAM_DEV_ID_0, CAM_CHN_ID_0)
    # create meida sink device
    globals()["meida_sink"] = media_device(DISPLAY_MOD_ID, DISPLAY_DEV_ID, DISPLAY_CHN_VIDEO1)
    # create meida link
    media.create_link(meida_source, meida_sink)
    # set display plane with video channel
    display.set_plane(0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT, PIXEL_FORMAT_YVU_PLANAR_420, DISPLAY_MIRROR_NONE, DISPLAY_CHN_VIDEO1)
    # set chn1 output nv12
    camera.set_outsize(CAM_DEV_ID_0, CAM_CHN_ID_1, DETECT_WIDTH, DETECT_HEIGHT)
    camera.set_outfmt(CAM_DEV_ID_0, CAM_CHN_ID_1, PIXEL_FORMAT_YUV_SEMIPLANAR_420)
    # media buffer init
    media.buffer_init()
    # request media buffer for osd image
    globals()["buffer"] = media.request_buffer(4 * DISPLAY_WIDTH * DISPLAY_HEIGHT)
    # start stream for camera device0
    camera.start_stream(CAM_DEV_ID_0)

def camera_deinit():
    # stop stream for camera device0
    camera.stop_stream(CAM_DEV_ID_0)
    # deinit display
    display.deinit()
    os.exitpoint(os.EXITPOINT_ENABLE_SLEEP)
    time.sleep_ms(100)
    # release media buffer
    media.release_buffer(globals()["buffer"])
    # destroy media link
    media.destroy_link(globals()["meida_source"], globals()["meida_sink"])
    # deinit media buffer
    media.buffer_deinit()

def capture_picture():
    # create image for drawing
    draw_img = image.Image(DISPLAY_WIDTH, DISPLAY_HEIGHT, image.ARGB8888)
    # create image for osd
    buffer = globals()["buffer"]
    osd_img = image.Image(DISPLAY_WIDTH, DISPLAY_HEIGHT, image.ARGB8888, alloc=image.ALLOC_VB, phyaddr=buffer.phys_addr, virtaddr=buffer.virt_addr, poolid=buffer.pool_id)
    osd_img.clear()
    display.show_image(osd_img, 0, 0, DISPLAY_CHN_OSD0)
    fps = time.clock()
    while True:
        fps.tick()
        try:
            os.exitpoint()
            yuv420_img = camera.capture_image(CAM_DEV_ID_0, CAM_CHN_ID_1)
            img = image.Image(yuv420_img.width(), yuv420_img.height(), image.GRAYSCALE, alloc=image.ALLOC_HEAP, data=yuv420_img)
            camera.release_image(CAM_DEV_ID_0, CAM_CHN_ID_1, yuv420_img)
            draw_img.clear()
            for tag in img.find_apriltags(families=tag_families):
                draw_img.draw_rectangle([v*SCALE for v in tag.rect()], color=(255, 0, 0))
                draw_img.draw_cross(tag.cx()*SCALE, tag.cy()*SCALE, color=(0, 255, 0))
                print_args = (family_name(tag), tag.id(), (180 * tag.rotation()) / math.pi)
                print("Tag Family %s, Tag ID %d, rotation %f (degrees)" % print_args)
            draw_img.copy_to(osd_img)
            print(fps.fps())
            del img
            gc.collect()
        except KeyboardInterrupt as e:
            print("user stop: ", e)
            break
        except BaseException as e:
            sys.print_exception(e)
            break

def main():
    os.exitpoint(os.EXITPOINT_ENABLE)
    camera_is_init = False
    try:
        print("camera init")
        camera_init()
        camera_is_init = True
        print("camera capture")
        capture_picture()
    except Exception as e:
        sys.print_exception(e)
    finally:
        if camera_is_init:
            print("camera deinit")
            camera_deinit()

if __name__ == "__main__":
    main()

具体接口使用请参考相关文档说明：

• camere

• display

• media

• image