Simplest and fastest version of image resizing. Source: https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation
| 5 | |
| 6 | |
| 7 | class NearestNeighbour: |
| 8 | """ |
| 9 | Simplest and fastest version of image resizing. |
| 10 | Source: https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation |
| 11 | """ |
| 12 | |
| 13 | def __init__(self, img, dst_width: int, dst_height: int): |
| 14 | if dst_width < 0 or dst_height < 0: |
| 15 | raise ValueError("Destination width/height should be > 0") |
| 16 | |
| 17 | self.img = img |
| 18 | self.src_w = img.shape[1] |
| 19 | self.src_h = img.shape[0] |
| 20 | self.dst_w = dst_width |
| 21 | self.dst_h = dst_height |
| 22 | |
| 23 | self.ratio_x = self.src_w / self.dst_w |
| 24 | self.ratio_y = self.src_h / self.dst_h |
| 25 | |
| 26 | self.output = self.output_img = ( |
| 27 | np.ones((self.dst_h, self.dst_w, 3), np.uint8) * 255 |
| 28 | ) |
| 29 | |
| 30 | def process(self): |
| 31 | for i in range(self.dst_h): |
| 32 | for j in range(self.dst_w): |
| 33 | self.output[i][j] = self.img[self.get_y(i)][self.get_x(j)] |
| 34 | |
| 35 | def get_x(self, x: int) -> int: |
| 36 | """ |
| 37 | Get parent X coordinate for destination X |
| 38 | :param x: Destination X coordinate |
| 39 | :return: Parent X coordinate based on `x ratio` |
| 40 | >>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg", |
| 41 | ... 1), 100, 100) |
| 42 | >>> nn.ratio_x = 0.5 |
| 43 | >>> nn.get_x(4) |
| 44 | 2 |
| 45 | """ |
| 46 | return int(self.ratio_x * x) |
| 47 | |
| 48 | def get_y(self, y: int) -> int: |
| 49 | """ |
| 50 | Get parent Y coordinate for destination Y |
| 51 | :param y: Destination X coordinate |
| 52 | :return: Parent X coordinate based on `y ratio` |
| 53 | >>> nn = NearestNeighbour(imread("digital_image_processing/image_data/lena.jpg", |
| 54 | ... 1), 100, 100) |
| 55 | >>> nn.ratio_y = 0.5 |
| 56 | >>> nn.get_y(4) |
| 57 | 2 |
| 58 | """ |
| 59 | return int(self.ratio_y * y) |
| 60 | |
| 61 | |
| 62 | if __name__ == "__main__": |