| import numpy as np |
| import cv2 |
|
|
| def make_coordinate_grid(image_size): |
| h, w = image_size |
| x = np.arange(w) |
| y = np.arange(h) |
| x = (2 * (x / (w - 1)) - 1) |
| y = (2 * (y / (h - 1)) - 1) |
| xx = x.reshape(1, -1).repeat(h, axis=0) |
| yy = y.reshape(-1, 1).repeat(w, axis=1) |
| meshed = np.stack([xx, yy], 2) |
| return meshed |
|
|
| def visualize_dense_flow(dense_flow): |
| hsv = np.zeros([dense_flow.shape[0], dense_flow.shape[1]]) |
| hsv = np.stack([hsv, hsv, hsv], 2).astype(np.uint8) |
| hsv[..., 1] = 255 |
| mag, ang = cv2.cartToPolar(dense_flow[:, :, 0], dense_flow[:, :, 1]) |
| hsv[..., 0] = ang * 180 / np.pi / 2 |
| hsv[..., 2] = cv2.normalize(mag, None, 0, 255, cv2.NORM_MINMAX) |
| rgb = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR) |
| rgb = rgb.astype(np.uint8) |
| return rgb |
