find_lines

# Find Lines Example
#
# This example shows off how to find lines in the image. For each line object
# found in the image a line object is returned which includes the line's rotation.

# Note: Line detection is done by using the Hough Transform:
# http://en.wikipedia.org/wiki/Hough_transform
# Please read about it above for more information on what `theta` and `rho` are.

# find_lines() finds infinite length lines. Use find_line_segments() to find non-infinite lines.

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

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

# All line objects have a `theta()` method to get their rotation angle in degrees.
# You can filter lines based on their rotation angle.

min_degree = 0
max_degree = 179

# All lines also have `x1()`, `y1()`, `x2()`, and `y2()` methods to get their end-points
# and a `line()` method to get all the above as one 4 value tuple for `draw_line()`.

# About negative rho values:
#
# A [theta+0:-rho] tuple is the same as [theta+180:+rho].

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_RGB_888)
    # 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()
            rgb888_img = camera.capture_image(CAM_DEV_ID_0, CAM_CHN_ID_1)
            img = rgb888_img.to_rgb565()
            camera.release_image(CAM_DEV_ID_0, CAM_CHN_ID_1, rgb888_img)
            draw_img.clear()
            # `threshold` controls how many lines in the image are found. Only lines with
            # edge difference magnitude sums greater than `threshold` are detected...

            # More about `threshold` - each pixel in the image contributes a magnitude value
            # to a line. The sum of all contributions is the magintude for that line. Then
            # when lines are merged their magnitudes are added togheter. Note that `threshold`
            # filters out lines with low magnitudes before merging. To see the magnitude of
            # un-merged lines set `theta_margin` and `rho_margin` to 0...

            # `theta_margin` and `rho_margin` control merging similar lines. If two lines
            # theta and rho value differences are less than the margins then they are merged.

            for l in img.find_lines(threshold = 1000, theta_margin = 25, rho_margin = 25):
                if (min_degree <= l.theta()) and (l.theta() <= max_degree):
                    draw_img.draw_line([v*SCALE for v in l.line()], color = (255, 0, 0))
                    print(l)
            draw_img.copy_to(osd_img)
            del img
            gc.collect()
            print(fps.fps())
        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