def _calc_video_frame_safe_boundary(self, frame_shape):
frame_width, frame_height = frame_shape
# Video frame boundary minus the frame edge buffer.
video_frame_safe_boundary = Rectangle(
(0 + self.frame_edge, 0 + self.frame_edge),
(frame_width - self.frame_edge, frame_height - self.frame_edge),
)
return video_frame_safe_boundary
def __init__(self,
frame_count,
frame_shape=None,
VERBOSE=False,
DEBUG=False):
"""
Initialize droplet labeler for a video frame.
"""
self._labels = OrderedDict()
self.frame = frame_count
self._VERBOSE = VERBOSE
self._DEBUG = DEBUG
self.frame_edge = 5
self._video_frame_safe_boundary = self._calc_video_frame_safe_boundary(
frame_shape)
self.video_frame_boundary = Rectangle((0, 0), frame_shape)
def _calc_center(self):
self.center = Rectangle(self.text_bounding_box[0].upper_left,
self.text_bounding_box[2].lower_right).center
def _calc_points(self):
# Text sizes. This is painful, as convincing opencv to do pixel-accurate text
# is icky. Breaking this into smaller pieces would be good, but going to PIL
# or Cairo/qahirah text would be better.
# (This is evolving - I added a Rectangle class to help understand overlaps
# between labels, and I'll back into using it here.)
# initial id
text_string = str(self.initial_id)
(
(
self._text_data["width"]["initial_id"],
self._text_data["height"]["initial_id"],
),
self._text_data["baseline"]["initial_id"],
) = cv2.getTextSize(text_string, cv2.FONT_HERSHEY_PLAIN, 1, 1)
self._text_data["height"][
"initial_id"] += 1 # fudge, as opencv reports height as one pixel less than it is
self._text_data["baseline"][
"initial_id"] -= 1 # fudge, baseline seems consistently 1 px big
# id
text_string = str(self.id)
(
(self._text_data["width"]["id"], self._text_data["height"]["id"]),
self._text_data["baseline"]["id"],
) = cv2.getTextSize(text_string, cv2.FONT_HERSHEY_PLAIN, 2, 1)
self._text_data["height"]["id"] += 1
self._text_data["baseline"][
"id"] -= 1 # fudge, baseline seems consistently 1 px big
# area in pixels as "Npx"
text_string = "{}px".format(self.area)
(
(self._text_data["width"]["area"],
self._text_data["height"]["area"]),
self._text_data["baseline"]["area"],
) = cv2.getTextSize(text_string, cv2.FONT_HERSHEY_PLAIN, 1, 1)
self._text_data["height"]["area"] += 1
self._text_data["baseline"][
"area"] -= 1 # fudge, baseline seems consistently 1 px big
[self._text_box_width] = max([self._text_data["width"][x]]
for x in self._text_data["width"])
self._text_box_height = (self._text_data["height"]["id"] +
self.leading +
self._text_data["baseline"]["area"] +
self.leading +
self._text_data["height"]["area"])
if self.initial_id != self.id:
self._text_box_height += self._text_data["height"]["initial_id"] + 1
# Bounding box corner points.
# These are the corner points on drawn contour bounding box, plus a stand-off
# distance, and from which the label bounding boxes can be drawn.
((x1, y1), (x2, y2)) = self._contour_bounding_box_corners
# 0th point is upper left, and then clockwise from there through 1, 2, and 3
self._corner_points[0] = (x1 - self.stand_off, y1 - self.stand_off)
self._corner_points[1] = (x2 + self.stand_off, y1 - self.stand_off)
self._corner_points[2] = (x2 + self.stand_off, y2 + self.stand_off)
self._corner_points[3] = (x1 - self.stand_off, y2 + self.stand_off)
# And the actual label text area bounding boxes.
self.text_bounding_box[0] = Rectangle(
(
self._corner_points[0][0] - self._text_box_width,
self._corner_points[0][1] - self._text_box_height,
),
self._corner_points[0],
)
self.text_bounding_box[1] = Rectangle(
(
self._corner_points[1][0],
self._corner_points[1][1] - self._text_box_height,
),
(
self._corner_points[1][0] + self._text_box_width,
self._corner_points[1][1],
),
)
self.text_bounding_box[2] = Rectangle(
self._corner_points[2],
(
self._corner_points[2][0] + self._text_box_width,
self._corner_points[2][1] + self._text_box_height,
),
)
self.text_bounding_box[3] = Rectangle(
(
self._corner_points[3][0] - self._text_box_width,
self._corner_points[3][1],
),
(
self._corner_points[3][0],
self._corner_points[3][1] + self._text_box_height,
),
)
