| import numpy as np | |
| def convert_to_square(bboxes): | |
| """Convert bounding boxes to a square form. | |
| Arguments: | |
| bboxes: a float numpy array of shape [n, 4]. | |
| Returns: | |
| a float numpy array of shape [4], | |
| squared bounding boxes. | |
| """ | |
| square_bboxes = np.zeros_like(bboxes) | |
| x1, y1, x2, y2 = bboxes | |
| h = y2 - y1 + 1.0 | |
| w = x2 - x1 + 1.0 | |
| max_side = np.maximum(h, w) | |
| square_bboxes[0] = x1 + w * 0.5 - max_side * 0.5 | |
| square_bboxes[1] = y1 + h * 0.5 - max_side * 0.5 | |
| square_bboxes[2] = square_bboxes[0] + max_side - 1.0 | |
| square_bboxes[3] = square_bboxes[1] + max_side - 1.0 | |
| return square_bboxes | |
| def scale_box(box, scale): | |
| x1, y1, x2, y2 = box | |
| center_x, center_y = (x1 + x2) / 2, (y1 + y2) / 2 | |
| w, h = x2 - x1, y2 - y1 | |
| new_w, new_h = w * scale, h * scale | |
| y1, y2, x1, x2 = center_y - new_h / 2, center_y + new_h / 2, center_x - new_w / 2, center_x + new_w / 2, | |
| return np.array((x1, y1, x2, y2)) | |