phase 12

tests/detect/test_preprocess.py

@@ -0,0 +1,84 @@
+"""Tests for OpenCV preprocessing — runs without GPU."""
+
+import numpy as np
+import pytest
+
+try:
+    import cv2
+    HAS_CV2 = True
+except ImportError:
+    HAS_CV2 = False
+
+requires_cv2 = pytest.mark.skipif(not HAS_CV2, reason="opencv-python-headless not installed")
+
+# Add gpu/ to path so imports resolve (gpu modules use relative imports)
+import sys
+from pathlib import Path
+sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "gpu"))
+
+
+def _make_image(w: int = 200, h: int = 60) -> np.ndarray:
+    """White image with black text-like region."""
+    img = np.ones((h, w, 3), dtype=np.uint8) * 255
+    img[15:45, 20:180] = 30  # dark band simulating text
+    return img
+
+
+@requires_cv2
+def test_binarize():
+    from gpu.models.preprocess import binarize
+
+    img = _make_image()
+    result = binarize(img)
+
+    assert result.shape == img.shape
+    assert result.dtype == np.uint8
+    # Should be mostly black and white (no grays)
+    unique_values = np.unique(result)
+    assert len(unique_values) <= 3  # 0, 255, maybe one more from anti-aliasing
+
+
+@requires_cv2
+def test_enhance_contrast():
+    from gpu.models.preprocess import enhance_contrast
+
+    img = _make_image()
+    result = enhance_contrast(img)
+
+    assert result.shape == img.shape
+    assert result.dtype == np.uint8
+
+
+@requires_cv2
+def test_deskew_no_rotation():
+    from gpu.models.preprocess import deskew
+
+    img = _make_image()
+    result = deskew(img)
+
+    assert result.shape == img.shape
+    # Straight image should be unchanged (angle < 0.5 deg)
+    assert np.allclose(result, img, atol=5)
+
+
+@requires_cv2
+def test_preprocess_pipeline():
+    from gpu.models.preprocess import preprocess
+
+    img = _make_image()
+
+    result = preprocess(img, do_binarize=False, do_deskew=False, do_contrast=True)
+    assert result.shape == img.shape
+
+    result = preprocess(img, do_binarize=True, do_deskew=True, do_contrast=True)
+    assert result.shape[:2] == img.shape[:2]  # h, w same; channels may differ then get converted back
+
+
+@requires_cv2
+def test_preprocess_all_disabled():
+    from gpu.models.preprocess import preprocess
+
+    img = _make_image()
+    result = preprocess(img, do_binarize=False, do_deskew=False, do_contrast=False)
+
+    assert np.array_equal(result, img)