| 97 | return data |
| 98 | |
| 99 | def draw_border_map(self, polygon, canvas, mask): |
| 100 | polygon = np.array(polygon) |
| 101 | assert polygon.ndim == 2 |
| 102 | assert polygon.shape[1] == 2 |
| 103 | |
| 104 | polygon_shape = Polygon(polygon) |
| 105 | if polygon_shape.area <= 0: |
| 106 | return |
| 107 | distance = (polygon_shape.area * (1 - np.power(self.shrink_ratio, 2)) / |
| 108 | polygon_shape.length) |
| 109 | subject = [tuple(l) for l in polygon] |
| 110 | padding = pyclipper.PyclipperOffset() |
| 111 | padding.AddPath(subject, pyclipper.JT_ROUND, |
| 112 | pyclipper.ET_CLOSEDPOLYGON) |
| 113 | |
| 114 | padded_polygon = np.array(padding.Execute(distance)[0]) |
| 115 | cv2.fillPoly(mask, [padded_polygon.astype(np.int32)], 1.0) |
| 116 | |
| 117 | xmin = padded_polygon[:, 0].min() |
| 118 | xmax = padded_polygon[:, 0].max() |
| 119 | ymin = padded_polygon[:, 1].min() |
| 120 | ymax = padded_polygon[:, 1].max() |
| 121 | width = xmax - xmin + 1 |
| 122 | height = ymax - ymin + 1 |
| 123 | |
| 124 | polygon[:, 0] = polygon[:, 0] - xmin |
| 125 | polygon[:, 1] = polygon[:, 1] - ymin |
| 126 | |
| 127 | xs = np.broadcast_to( |
| 128 | np.linspace(0, width - 1, num=width).reshape(1, width), |
| 129 | (height, width)) |
| 130 | ys = np.broadcast_to( |
| 131 | np.linspace(0, height - 1, num=height).reshape(height, 1), |
| 132 | (height, width)) |
| 133 | |
| 134 | distance_map = np.zeros((polygon.shape[0], height, width), |
| 135 | dtype=np.float32) |
| 136 | for i in range(polygon.shape[0]): |
| 137 | j = (i + 1) % polygon.shape[0] |
| 138 | absolute_distance = self._distance(xs, ys, polygon[i], polygon[j]) |
| 139 | distance_map[i] = np.clip(absolute_distance / distance, 0, 1) |
| 140 | distance_map = distance_map.min(axis=0) |
| 141 | |
| 142 | xmin_valid = min(max(0, xmin), canvas.shape[1] - 1) |
| 143 | xmax_valid = min(max(0, xmax), canvas.shape[1] - 1) |
| 144 | ymin_valid = min(max(0, ymin), canvas.shape[0] - 1) |
| 145 | ymax_valid = min(max(0, ymax), canvas.shape[0] - 1) |
| 146 | canvas[ymin_valid:ymax_valid + 1, xmin_valid:xmax_valid + 1] = np.fmax( |
| 147 | 1 - distance_map[ymin_valid - ymin:ymax_valid - ymax + height, |
| 148 | xmin_valid - xmin:xmax_valid - xmax + width, ], |
| 149 | canvas[ymin_valid:ymax_valid + 1, xmin_valid:xmax_valid + 1], |
| 150 | ) |
| 151 | |
| 152 | def _distance(self, xs, ys, point_1, point_2): |
| 153 | """ |