# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""This module contains different functions to draw coordinates and orientations on images."""
import cv2
import numpy as np
# adapted from:
# https://github.com/BioroboticsLab/bb_pipeline/blob/master/pipeline/stages/visualization.py
[docs]def draw_arrows(img, positions, angles, color=(0, 0, 255), line_width=6, arrow_length=150):
u"""Draw arrows from positions in angle direction (clockwise).
(The 0°-Angle is the x-Axis.)
Args:
img (ndarray): Image (min. 3 channel) to draw on.
positions (ndarray): The points the arrows starts from. *(N,2)*
angles (ndarray): Angles in rad (length *(N,)*).
"""
assert len(positions) == len(angles)
for i, position in enumerate(positions):
position = position.astype(np.int32)
x_to = np.round(position[0] + arrow_length * np.cos(angles[i])).astype(np.int32)
y_to = np.round(position[1] + arrow_length * np.sin(angles[i])).astype(np.int32)
cv2.arrowedLine(img, tuple(position), (x_to, y_to), color, line_width, cv2.LINE_AA)
[docs]def draw_circles(img, centres, radius=32, color=(0, 0, 255), line_width=6):
"""Draw circles around positions.
Args:
img (ndarray): Image (min. 3 channel) to draw on.
centres (ndarray): The centres of the circles. *(N,2)*
radius: Radius of the circles.
"""
for center in centres:
center = center.astype(np.int32)
cv2.circle(img, tuple(center), radius, color, line_width)
[docs]def draw_marks(img, positions, color=(0, 0, 255), marker_types=cv2.MARKER_CROSS):
"""Draw cross marks on position.
Args:
img (ndarray): Image (min. 3 channel) to draw on.
positions (ndarray): The points to mark. *(N,2)*
"""
for position in positions.astype(int):
cv2.drawMarker(img, tuple(position), color, markerType=marker_types,
markerSize=40, thickness=5)
[docs]def draw_complex_marks(img, centres, angles, color=(0, 0, 255), marker_types=cv2.MARKER_CROSS):
"""Draw more complex marks, with circles, marked centres and arrows for angles/direction.
Args:
img (ndarray): Image (min. 3 channel) to draw on.
centres (ndarray): The centres of the marks and starting points of arrows. *(N,2)*
angles (ndarray): Angles in rad (length *(N,)*).
"""
arrow_length = 150
assert len(centres) == len(angles)
for i, center in enumerate(centres):
center = center.astype(np.int32)
x_to = np.round(center[0] + arrow_length * np.cos(angles[i])).astype(np.int32)
y_to = np.round(center[1] + arrow_length * np.sin(angles[i])).astype(np.int32)
cv2.arrowedLine(img, tuple(center), (x_to, y_to), color, thickness=6, line_type=cv2.LINE_AA)
cv2.circle(img, tuple(center), radius=32, color=color, thickness=6)
cv2.drawMarker(img, tuple(center), color, markerType=marker_types,
markerSize=40, thickness=1)
[docs]def draw_grid(image, origin, ratio_px_mm, step_size_mm=8):
"""Draw a grid with axes in mm on the image.
Args:
image (ndarray): Image to draw on.
origin (ndarray): The orgin of the grid / axes.
ratio_px_mm: Ratio to convert pixel to mm.
step_size_mm: The (step) distance between the grid lines.
"""
w, h = image.shape[:2][::-1]
x, y = origin
step_size_px = step_size_mm / ratio_px_mm
# draw vertical lines in mm
max_lines_vert = int((w - x) / step_size_px)
for i in range(max_lines_vert):
pt1_v = np.zeros((2,), dtype=np.uint16)
pt1_v[0] = x + i * step_size_px
pt1_v[1] = y
pt1_v = tuple(pt1_v)
pt2_v = (int(pt1_v[0]), h)
cv2.line(image, pt1_v, pt2_v, color=(255, 0, 0), thickness=4)
cv2.putText(image, str(i * step_size_mm), pt1_v, cv2.FONT_HERSHEY_PLAIN, 2, (0, 0, 255),
thickness=4)
# draw horizontal lines and distance in mm
max_lines_hori = int((h - y) / step_size_px)
for i in range(max_lines_hori):
pt1_h = np.zeros((2,), dtype=np.uint16)
pt1_h[0] = x
pt1_h[1] = y + i * step_size_px
pt1_h = tuple(np.uint16(pt1_h))
pt2_h = (w, int(pt1_h[1]))
cv2.line(image, pt1_h, pt2_h, color=(255, 0, 0), thickness=4)
cv2.putText(image, str(i * step_size_mm), pt1_h, cv2.FONT_HERSHEY_PLAIN, 2, (0, 0, 255),
thickness=4)