"""固定边长切片：只裁剪与镜像填充，不缩放。""" import pytest np = pytest.importorskip("numpy") from engine.detection import Box, from_yolo # noqa: E402 from engine.tiling import axis_starts, cut, plan_tiles, remap_boxes, to_source # noqa: E402 SIZE = 160 # ---------------- 切片网格 ---------------- @pytest.mark.parametrize( "length,overlap,expected", [ (160, 0, [0]), # 正好一片 (128, 0, [0]), # 不足，填充 (320, 0, [0, 160]), # 整两片 (200, 0, [0, 40]), # 最后一片贴边，与前片重叠 120 (480, 32, [0, 128, 256, 320]), # 步长 128，末片贴边 ], ) def test_axis_starts(length, overlap, expected): assert axis_starts(length, SIZE, overlap) == expected def test_last_tile_always_reaches_the_edge(): """末尾那条不足一步的区域不能被漏掉。""" for length in range(161, 700): starts = axis_starts(length, SIZE, 16) assert starts[-1] + SIZE == length def test_plan_tiles_covers_a_large_image(): tiles = plan_tiles(524, 959, SIZE, overlap=0) assert len(tiles) == len(axis_starts(524, SIZE, 0)) * len(axis_starts(959, SIZE, 0)) assert all(t.pad_left == 0 and t.pad_top == 0 for t in tiles) # 大图纯裁剪 def test_small_image_is_centred_and_padded(): tile, = plan_tiles(116, 83, SIZE) assert (tile.crop_width, tile.crop_height) == (116, 83) assert tile.pad_left == (160 - 116) // 2 == 22 assert tile.pad_top == (160 - 83) // 2 == 38 @pytest.mark.parametrize("bad", [0, -1]) def test_rejects_invalid_size(bad): with pytest.raises(ValueError, match="size"): plan_tiles(100, 100, bad) @pytest.mark.parametrize("bad", [-1, 160, 200]) def test_rejects_invalid_overlap(bad): with pytest.raises(ValueError, match="overlap"): plan_tiles(300, 300, SIZE, bad) # ---------------- 取片 ---------------- def test_cut_crops_without_resizing(): """大图取片必须是原像素的子块，一个插值都不能有。""" image = np.arange(300 * 400, dtype=np.uint8).reshape(300, 400) % 251 tile = plan_tiles(400, 300, SIZE, overlap=0)[1] # 第二片，x 有偏移 patch = cut(image, tile, SIZE) assert patch.shape == (SIZE, SIZE) expected = image[tile.y:tile.y + SIZE, tile.x:tile.x + SIZE] assert np.array_equal(patch, expected) def test_cut_mirrors_small_images(): image = np.arange(1, 5, dtype=np.uint8).reshape(1, 4) # 1x4 tile, = plan_tiles(4, 1, 4) patch = cut(image, tile, 4) assert patch.shape == (4, 4) # 竖直方向镜像：原始那一行在中间，上下是它的倒影（reflect 不重复边缘行） assert np.array_equal(patch[tile.pad_top], image[0]) assert patch.dtype == image.dtype def test_cut_keeps_channels(): image = np.zeros((50, 60, 3), dtype=np.uint8) tile, = plan_tiles(60, 50, SIZE) assert cut(image, tile, SIZE).shape == (SIZE, SIZE, 3) def test_cut_of_an_exact_size_image_is_the_image_itself(): image = np.random.default_rng(0).integers(0, 255, (SIZE, SIZE), dtype=np.uint8) tile, = plan_tiles(SIZE, SIZE, SIZE) assert np.array_equal(cut(image, tile, SIZE), image) # ---------------- 框的重映射 ---------------- def test_box_shifts_with_padding(): """小图居中填充后，框只是整体平移。""" width, height = 80, 80 box = from_yolo(3, 0.5, 0.5, 0.25, 0.25) # 原图中心 20x20 的框 tile, = plan_tiles(width, height, SIZE) mapped, = remap_boxes([box], tile, width, height, SIZE) assert mapped.class_id == 3 # 原图中心落在片中心 assert (mapped.x1 + mapped.x2) / 2 == pytest.approx(0.5) # 尺寸不变：原来 20 像素，片上还是 20 像素（占 160 的 1/8） assert (mapped.x2 - mapped.x1) * SIZE == pytest.approx(20) def test_box_outside_the_tile_is_dropped(): width = height = 400 box = from_yolo(0, 0.9, 0.9, 0.05, 0.05) # 右下角 first = plan_tiles(width, height, SIZE, overlap=0)[0] # 左上片 assert remap_boxes([box], first, width, height, SIZE) == [] def test_partially_visible_box_is_clipped_or_dropped(): """跨片的框：露得多就裁剪保留，露得少就丢弃。""" width = height = 320 # 框中心正好在 x=160 的切割线上，左右各露一半 box = from_yolo(1, 160 / width, 0.25, 40 / width, 40 / height) left, right = plan_tiles(width, height, SIZE, overlap=0)[:2] kept_left, = remap_boxes([box], left, width, height, SIZE, min_visibility=0.4) assert kept_left.x2 == pytest.approx(1.0) # 裁到片的右边缘 assert (kept_left.x2 - kept_left.x1) * SIZE == pytest.approx(20) # 阈值提到 0.6 时，只露一半就不够了 assert remap_boxes([box], left, width, height, SIZE, min_visibility=0.6) == [] assert remap_boxes([box], right, width, height, SIZE, min_visibility=0.6) == [] def test_mirrored_region_gets_no_box(): """镜像出来的是复制品，不能再给它标框——否则等于告诉模型那里真有缺陷。""" width = height = 80 box = from_yolo(0, 0.5, 0.5, 0.5, 0.5) tile, = plan_tiles(width, height, SIZE) mapped = remap_boxes([box], tile, width, height, SIZE) assert len(mapped) == 1 # 只有一个，不是四个倒影 # 框整体落在原图内容的范围内 assert mapped[0].x1 * SIZE >= tile.pad_left - 1e-6 assert mapped[0].x2 * SIZE <= tile.pad_left + tile.crop_width + 1e-6 def test_zero_area_box_is_ignored(): tile, = plan_tiles(100, 100, SIZE) degenerate = Box(0, 0.5, 0.5, 0.5, 0.5) assert remap_boxes([degenerate], tile, 100, 100, SIZE) == [] # ---------------- 反向映射 ---------------- @pytest.mark.parametrize("size_wh", [(80, 60), (400, 300), (160, 160), (524, 959)]) def test_round_trip_back_to_source(size_wh): """片上的框映射回原图，必须落回原来的像素位置。 框放在某一片裁剪区域的正中，确保它完整落在该片内——无重叠切片时， 原图正中的框反而可能横跨切割线，不适合用来做往返校验。 """ width, height = size_wh for tile in plan_tiles(width, height, SIZE, overlap=0): cx = tile.x + tile.crop_width / 2 cy = tile.y + tile.crop_height / 2 half_w = min(tile.crop_width, 20) / 4 half_h = min(tile.crop_height, 20) / 4 px = [cx - half_w, cy - half_h, cx + half_w, cy + half_h] box = Box(2, px[0] / width, px[1] / height, px[2] / width, px[3] / height) mapped, = remap_boxes([box], tile, width, height, SIZE, min_visibility=0.99) back = to_source(mapped, tile, SIZE) assert [back.x1, back.y1, back.x2, back.y2] == pytest.approx(px, abs=1e-6) def test_score_survives_both_directions(): tile, = plan_tiles(100, 100, SIZE) box = Box(1, 0.4, 0.4, 0.6, 0.6, 0.83) mapped, = remap_boxes([box], tile, 100, 100, SIZE) assert mapped.score == 0.83 assert to_source(mapped, tile, SIZE).score == 0.83