def __init__(self,
corners: geometry_utils.Polygon,
horizontal_cells: int,
vertical_cells: int,
image: np.ndarray,
save_path: typing.Optional[pathlib.PurePath] = None):
"""Initiate a new Grid. Corners should be clockwise starting from the
top left - if not, the grid will have unexpected behavior.
If `save_path` is provided, will save the resulting image to this location
as "grid.jpg". Used for debugging purposes."""
self.corners = corners
self.horizontal_cells = horizontal_cells
self.vertical_cells = vertical_cells
self._to_grid_basis, self._from_grid_basis = geometry_utils.create_change_of_basis(
corners[0], corners[3], corners[2])
self.horizontal_cell_size = 1 / self.horizontal_cells
self.vertical_cell_size = 1 / self.vertical_cells
self.image = image
if save_path:
image_utils.save_image(save_path / "grid.jpg", self.draw_grid())
def find_corner_marks(image: np.ndarray,
save_path: typing.Optional[pathlib.PurePath] = None
) -> geometry_utils.Polygon:
all_polygons: typing.List[
geometry_utils.Polygon] = image_utils.find_polygons(
image, save_path=save_path)
# Even though the LMark and SquareMark classes check length, it's faster to
# filter out the shapes of incorrect length despite the increased time
# complexity.
hexagons: typing.List[geometry_utils.Polygon] = []
quadrilaterals: typing.List[geometry_utils.Polygon] = []
for poly in all_polygons:
if len(poly) == 6:
hexagons.append(poly)
elif len(poly) == 4:
quadrilaterals.append(poly)
for hexagon in hexagons:
try:
l_mark = LMark(hexagon)
except WrongShapeError:
continue
to_new_basis, _ = geometry_utils.create_change_of_basis(
l_mark.polygon[0], l_mark.polygon[5], l_mark.polygon[4])
nominal_to_right_side = 50 - 0.5
nominal_to_bottom = ((64 - 0.5) / 2)
tolerance = 0.1 * nominal_to_right_side
top_right_squares = []
bottom_left_squares = []
bottom_right_squares = []
for quadrilateral in quadrilaterals:
try:
square = SquareMark(quadrilateral, l_mark.unit_length)
except WrongShapeError:
continue
centroid = geometry_utils.guess_centroid(square.polygon)
centroid_new_basis = to_new_basis(centroid)
if math_utils.is_within_tolerance(
centroid_new_basis.x, nominal_to_right_side,
tolerance) and math_utils.is_within_tolerance(
centroid_new_basis.y, 0.5, tolerance):
top_right_squares.append(square)
elif math_utils.is_within_tolerance(
centroid_new_basis.x, 0.5,
tolerance) and math_utils.is_within_tolerance(
centroid_new_basis.y, nominal_to_bottom, tolerance):
bottom_left_squares.append(square)
elif math_utils.is_within_tolerance(
centroid_new_basis.x, nominal_to_right_side,
tolerance) and math_utils.is_within_tolerance(
centroid_new_basis.y, nominal_to_bottom, tolerance):
bottom_right_squares.append(square)
if len(top_right_squares) == 0 or len(bottom_left_squares) == 0 or len(
bottom_right_squares) == 0:
continue
# TODO: When multiple, either progressively decrease tolerance or
# choose closest to centroid
top_left_corner = l_mark.polygon[0]
top_right_corner = geometry_utils.get_corner(
top_right_squares[0].polygon, geometry_utils.Corner.TR)
bottom_right_corner = geometry_utils.get_corner(
bottom_right_squares[0].polygon, geometry_utils.Corner.BR)
bottom_left_corner = geometry_utils.get_corner(
bottom_left_squares[0].polygon, geometry_utils.Corner.BL)
return [
top_left_corner, top_right_corner, bottom_right_corner,
bottom_left_corner
]
raise RuntimeError("Couldn't find document corners.")