def test_locate_returns_None_if_no_internal_templates_found_in_scene(self):
# setup a template and scene that should be guaranteed not to be matched
black_template = _generic_image(height=5, width=10)
black_template.fill(0)
white_scene = _generic_image(height=20, width=20)
white_scene.fill(255)
tf = TemplateFinder(black_template)
p = tf.locate_in(white_scene)
self.assertIsNone(p)
def test_locate_multiple_returns_empty_sequence_if_nothing_found(self):
# setup a template and scene that should be guaranteed not to be matched
black_template = _generic_image(height=5, width=10)
black_template.fill(0)
white_scene = _generic_image(height=20, width=20)
white_scene.fill(255)
tf = TemplateFinder(black_template)
p = tf.locate_multiple_in(white_scene)
empty_sequence = tuple()
self.assertSequenceEqual(p, empty_sequence)
def test_locate_multiple_returns_all_matches_better_than_acceptable(self):
# put a set of black "images" on a white background to be searched for
tlbr_specs = [(2, 2, 4, 4),
(5, 5, 7, 7),
(8, 8, 10, 10)]
white_scene = _generic_image(height=20, width=20)
white_scene.fill(255)
black_template = _generic_image(height=2, width=2)
black_template.fill(0)
# setup thresholds to exercise the spec
tf = TemplateFinder(black_template,
acceptable_threshold=1,
immediate_threshold=1)
# set black squares to match the template
for t, l, b, r in tlbr_specs:
white_scene[t:b, l:r] = 0
borders = tf.locate_multiple_in(white_scene)
self.assertItemsEqual(borders, tlbr_specs)
def test_locate_returns_result_immediately_when_immediate_passes(self):
top_spec, left_spec, bottom_spec, right_spec = 2, 3, 22, 33
height_spec = bottom_spec - top_spec
width_spec = right_spec - left_spec
black_template = _generic_image(height=height_spec,
width=width_spec)
black_template.fill(0)
white_scene = _generic_image(height=height_spec * 3,
width=width_spec * 3)
white_scene.fill(255)
# set a black square to match the template
white_scene[top_spec:bottom_spec, left_spec:right_spec] = 0
# setup thresholds to exercise the spec
impossible = -1
always = 2
tf = TemplateFinder(black_template, acceptable_threshold=impossible,
immediate_threshold=always)
# confirm the result
borders = tf.locate_in(white_scene)
self.assertEqual(borders,
(top_spec, left_spec, bottom_spec, right_spec))
