def sample(self):
if hasattr(self, '_sample'):
return self._sample, self._sample_size
self._sample = {}
self._sample_size = 0
_, n = self.positive
positives = self._positive_expanded
n = int(n * self.ratio)
TT.debug("Collecting", n, "random samples.")
pixels_per_image = int(np.prod(self.image_size))
indices = xrange(len(self.files) * pixels_per_image)
ignored = 0
for index in random.sample(indices, n):
data_file, label_file = self.files[index / pixels_per_image]
if data_file not in self._sample:
self._sample[data_file] = []
pixel = index % pixels_per_image
p = 0.0
if data_file in positives and pixel in positives[data_file]:
p = 1.0
ignored += 1
col, row = pixel_at_index(pixel, self.image_size)
self._sample[data_file].append([col, row, p])
self._sample_size += 1
TT.debug(ignored, "samples out of", self._sample_size,
"random samples are positive.")
self.positive_in_sample = ignored
return self.sample
def __iter__(self):
for i in xrange(len(self)):
col, row = pixel_at_index(i, self.image_size)
yield patch_centered_at(self.input,
row=row,
col=col,
size=self.patch_size), self.output[row,
col]
def test_pixel_at():
global image
size = image_size(image)
# 2. pixel index to row, col
assert (500, 2) == pixel_at_index(1700, size)
# 3. row, col to pixel index
assert 1700 == index_at_pixel(500, 2, size)
assert 120400 == index_at_pixel(400, 200, size)
