Find Line Segments Example

# This work is licensed under the MIT license.
# Copyright (c) 2013-2023 OpenMV LLC. All rights reserved.
# https://github.com/openmv/openmv/blob/master/LICENSE
#
# Find Line Segments Example
#
# This example shows off how to find line segments in the image. For each line object
# found in the image a line object is returned which includes the line's rotation.

# find_line_segments() finds finite length lines (but is slow).
# Use find_line_segments() to find non-infinite lines (and is fast).

import csi
import time

ENABLE_LENS_CORR = False  # turn on for straighter lines...

csi0 = csi.CSI()
csi0.reset()
csi0.pixformat(csi.RGB565)  # grayscale is faster
csi0.framesize(csi.QQVGA)
csi0.snapshot(time=2000)

clock = time.clock()

# All lines also have `x1`, `y1`, `x2`, and `y2` attributes to get their end-points.
# Line objects can be passed directly to `draw_line()`.

while True:
    clock.tick()
    img = csi0.snapshot()
    if ENABLE_LENS_CORR:
        img.lens_corr(1.8)  # for 2.8mm lens...

    # `merge_distance` controls the merging of nearby lines. At 0 (the default), no
    # merging is done. At 1, any line 1 pixel away from another is merged... and so
    # on as you increase this value. You may wish to merge lines as line segment
    # detection produces a lot of line segment results.

    # `max_theta_diff` controls the maximum amount of rotation difference between
    # any two lines about to be merged. The default setting allows for 15 degrees.

    for l in img.find_line_segments(merge_distance=0, max_theta_diff=5):
        img.draw_line(l, color=(255, 0, 0))
        # print(l)

    print("FPS %f" % clock.fps())