bookmark/tests/test_image_processing.py

44 lines
1.3 KiB
Python

import numpy as np
import pytest
from bookmark.image_processing import crop_to_book
def make_reference(size=100, color=200):
return np.full((size, size, 3), color, dtype=np.uint8)
def make_book_frame(size=100, ref_color=200, book_color=50, box=(30, 30, 20, 20)):
frame = np.full((size, size, 3), ref_color, dtype=np.uint8)
x, y, w, h = box
frame[y:y + h, x:x + w] = book_color
return frame
def test_crop_raises_when_no_difference_from_reference():
reference = make_reference()
with pytest.raises(ValueError):
crop_to_book(reference.copy(), reference)
def test_crop_returns_region_around_book_with_margin():
reference = make_reference()
frame = make_book_frame(box=(30, 30, 20, 20))
cropped = crop_to_book(frame, reference, margin=10)
# book occupies x:[30,50) y:[30,50), with margin=10 expected crop is
# roughly x:[20,60) y:[20,60) -> 40x40
assert cropped.shape[0] == pytest.approx(40, abs=2)
assert cropped.shape[1] == pytest.approx(40, abs=2)
def test_crop_clamps_margin_to_frame_bounds():
reference = make_reference()
frame = make_book_frame(box=(0, 0, 20, 20))
cropped = crop_to_book(frame, reference, margin=10)
# book touches top-left corner, margin should clamp instead of going negative
assert cropped.shape[0] <= 30
assert cropped.shape[1] <= 30