Calculate image gradient. Input: im: h x w x c numpy array
(im)
| 517 | return {'gradx': gradx, 'grady': grady, 'grad':grad} |
| 518 | |
| 519 | def imgrad_fft(im): |
| 520 | ''' |
| 521 | Calculate image gradient. |
| 522 | Input: |
| 523 | im: h x w x c numpy array |
| 524 | ''' |
| 525 | wx = np.rot90(np.array([[0, 0, 0], |
| 526 | [-1, 1, 0], |
| 527 | [0, 0, 0]], dtype=np.float32), k=2) |
| 528 | gradx = convfft(im, wx) |
| 529 | wy = np.rot90(np.array([[0, -1, 0], |
| 530 | [0, 1, 0], |
| 531 | [0, 0, 0]], dtype=np.float32), k=2) |
| 532 | grady = convfft(im, wy) |
| 533 | grad = np.concatenate((gradx, grady), axis=2) |
| 534 | |
| 535 | return {'gradx': gradx, 'grady': grady, 'grad':grad} |
| 536 | |
| 537 | def convfft(im, weight): |
| 538 | ''' |