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import cv2 as cv
import numpy as np
W = 400
## [my_ellipse]
def my_ellipse(img, angle):
thickness = 2
line_type = 8
cv.ellipse(img,
(W // 2, W // 2),
(W // 4, W // 16),
angle,
0,
360,
(255, 0, 0),
thickness,
line_type)
## [my_ellipse]
## [my_filled_circle]
def my_filled_circle(img, center):
thickness = -1
line_type = 8
cv.circle(img,
center,
W // 32,
(0, 0, 255),
thickness,
line_type)
## [my_filled_circle]
## [my_polygon]
def my_polygon(img):
line_type = 8
# Create some points
ppt = np.array([[W / 4, 7 * W / 8], [3 * W / 4, 7 * W / 8],
[3 * W / 4, 13 * W / 16], [11 * W / 16, 13 * W / 16],
[19 * W / 32, 3 * W / 8], [3 * W / 4, 3 * W / 8],
[3 * W / 4, W / 8], [26 * W / 40, W / 8],
[26 * W / 40, W / 4], [22 * W / 40, W / 4],
[22 * W / 40, W / 8], [18 * W / 40, W / 8],
[18 * W / 40, W / 4], [14 * W / 40, W / 4],
[14 * W / 40, W / 8], [W / 4, W / 8],
[W / 4, 3 * W / 8], [13 * W / 32, 3 * W / 8],
[5 * W / 16, 13 * W / 16], [W / 4, 13 * W / 16]], np.int32)
ppt = ppt.reshape((-1, 1, 2))
cv.fillPoly(img, [ppt], (255, 255, 255), line_type)
# Only drawind the lines would be:
# cv.polylines(img, [ppt], True, (255, 0, 255), line_type)
## [my_polygon]
## [my_line]
def my_line(img, start, end):
thickness = 2
line_type = 8
cv.line(img,
start,
end,
(0, 0, 0),
thickness,
line_type)
## [my_line]
## [create_images]
# Windows names
atom_window = "Drawing 1: Atom"
rook_window = "Drawing 2: Rook"
# Create black empty images
size = W, W, 3
atom_image = np.zeros(size, dtype=np.uint8)
rook_image = np.zeros(size, dtype=np.uint8)
## [create_images]
## [draw_atom]
# 1. Draw a simple atom:
# -----------------------
# 1.a. Creating ellipses
my_ellipse(atom_image, 90)
my_ellipse(atom_image, 0)
my_ellipse(atom_image, 45)
my_ellipse(atom_image, -45)
# 1.b. Creating circles
my_filled_circle(atom_image, (W // 2, W // 2))
## [draw_atom]
## [draw_rook]
# 2. Draw a rook
# ------------------
# 2.a. Create a convex polygon
my_polygon(rook_image)
## [rectangle]
# 2.b. Creating rectangles
cv.rectangle(rook_image,
(0, 7 * W // 8),
(W, W),
(0, 255, 255),
-1,
8)
## [rectangle]
# 2.c. Create a few lines
my_line(rook_image, (0, 15 * W // 16), (W, 15 * W // 16))
my_line(rook_image, (W // 4, 7 * W // 8), (W // 4, W))
my_line(rook_image, (W // 2, 7 * W // 8), (W // 2, W))
my_line(rook_image, (3 * W // 4, 7 * W // 8), (3 * W // 4, W))
## [draw_rook]
cv.imshow(atom_window, atom_image)
cv.moveWindow(atom_window, 0, 200)
cv.imshow(rook_window, rook_image)
cv.moveWindow(rook_window, W, 200)
cv.waitKey(0)
cv.destroyAllWindows()