adds anchor grid

mmp/a4/anchor_grid.py

@@ -9,4 +9,24 @@ def get_anchor_grid(
     anchor_widths: Sequence[float],
     aspect_ratios: Sequence[float],
 ) -> np.ndarray:
-    raise NotImplementedError()
+    anchor_grid = np.empty(
+        [len(width), len(ratio), num_rows, num_cols, 4], dtype=int)
+    for width_idx, width in enumerate(anchor_widths):
+        for ratio_idx, ratio in enumerate(aspect_ratios):
+            for row in range(num_rows):
+                for col in range(num_cols):
+                    anchor_point = (
+                        col * scale_factor + scale_factor/2, row * scale_factor + scale_factor / 2)
+                    anchor_grid[width_idx, ratio_idx, row, col] = get_box(
+                        width, ratio, anchor_point)
+
+    return anchor_grid
+
+
+def get_box(width: float, ratio: float, anchor_point: tuple[float, float]) -> np.ndarray:
+    box = np.empty(4)
+    box[0] = anchor_point[0] - (width / 2)
+    box[1] = anchor_point[1] - (width * ratio / 2)
+    box[2] = anchor_point[0] + (width / 2)
+    box[3] = anchor_point[1] + (width * ratio / 2)
+    return box

mmp/a4/label_grid.py

@@ -5,10 +5,34 @@ from ..a3.annotation import AnnotationRect
 
 
 def iou(rect1: AnnotationRect, rect2: AnnotationRect) -> float:
-    raise NotImplementedError()
+    x_left = max(rect1.x1, rect2.x1)
+    y_top = max(rect1.y1, rect2.y1)
+    x_right = min(rect1.x2, rect2.x2)
+    y_bottom = min(rect1.y2, rect2.y2)
+
+    # Returns 0 if no overlap
+    if x_right <= x_left or y_bottom <= y_top:
+        return 0.0
+
+    intersection_area = (x_right - x_left) * (y_bottom - y_top)
+
+    rect1_area = rect1.area()
+    rect2_area = rect2.area()
+
+    union_area = rect1_area + rect2_area - intersection_area
+
+    return intersection_area / union_area
 
 
 def get_label_grid(
     anchor_grid: np.ndarray, gts: Sequence[AnnotationRect], min_iou: float
 ) -> tuple[np.ndarray, ...]:
-    raise NotImplementedError()
+    label_grid = np.empty(anchor_grid.shape[:-1], dtype=bool)
+    for (width, ratio, row, col), item in np.ndenumerate(anchor_grid):
+        for gt in gts:
+            iou = iou(item, gt)
+            label_grid[width, ratio, row, col] = False
+            if (iou >= min_iou):
+                label_grid[width, ratio, row, col] = True
+                break
+    return label_grid