def extract_img(image_file: str) -> Image:
"""Extracts and returns embedded image from PDS3 IMG files as PIL Image.
Args:
image_file (str): path to .IMG file.
Returns:
PIL.Image
"""
# Parsing label
label = pvl.load(image_file) # load label from .IMG file
image_data = label['IMAGE'] # getting image object info
h_img, w_img = image_data[0][-1], image_data[1][-1] # real image sizes
pref, suff = image_data[6][-1], image_data[7][-1] # buffer pixels margins
w_total = w_img + pref + suff # width with margins
offset = label['^IMAGE'].value # pointer where image is located
size = label['^GAP_TABLE'].value - label[
'^IMAGE'].value # image size (in bytes)
# Now getting back to file
with open(image_file, "rb") as f:
container = ContainerIO.ContainerIO(f, offset - 1, size)
data = container.read() # reading image bytes
img = Image.frombytes('L', (w_total, h_img), data, "raw") # decoding
img = img.crop((pref, 0, w_img + pref, h_img)) # cropping margins
return img
def test_readline():
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 0, 120)
# Act
data = container.readline()
# Assert
assert data == "This is line 1\n"
def test_readline(self):
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 0, 120)
# Act
data = container.readline()
# Assert
self.assertEqual(data, "This is line 1\n")
def test_read_eof():
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(100)
data = container.read()
# Assert
assert data == ""
def test_read_n0():
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(81)
data = container.read()
# Assert
assert data == "7\nThis is line 8\n"
def test_read_n0(self):
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(81)
data = container.read()
# Assert
self.assertEqual(data, "7\nThis is line 8\n")
def test_read_eof(self):
# Arrange
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(100)
data = container.read()
# Assert
self.assertEqual(data, "")
def test_seek_mode_2():
# Arrange
mode = 2
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(33, mode)
container.seek(33, mode)
# Assert
assert container.tell() == 100
def test_seek_mode_2(self):
# Arrange
mode = 2
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(33, mode)
container.seek(33, mode)
# Assert
self.assertEqual(container.tell(), 100)
def test_readline():
# Arrange
for bytesmode in (True, False):
with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
container = ContainerIO.ContainerIO(fh, 0, 120)
# Act
data = container.readline()
# Assert
if bytesmode:
data = data.decode()
assert data == "This is line 1\n"
def test_read_eof():
# Arrange
for bytesmode in (True, False):
with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
container = ContainerIO.ContainerIO(fh, 22, 100)
# Act
container.seek(100)
data = container.read()
# Assert
if bytesmode:
data = data.decode()
assert data == ""
def test_readlines(self):
# Arrange
expected = [
"This is line 1\n", "This is line 2\n", "This is line 3\n",
"This is line 4\n", "This is line 5\n", "This is line 6\n",
"This is line 7\n", "This is line 8\n"
]
with open(TEST_FILE) as fh:
container = ContainerIO.ContainerIO(fh, 0, 120)
# Act
data = container.readlines()
# Assert
self.assertEqual(data, expected)
def test_readlines():
# Arrange
for bytesmode in (True, False):
expected = [
"This is line 1\n",
"This is line 2\n",
"This is line 3\n",
"This is line 4\n",
"This is line 5\n",
"This is line 6\n",
"This is line 7\n",
"This is line 8\n",
]
with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
container = ContainerIO.ContainerIO(fh, 0, 120)
# Act
data = container.readlines()
# Assert
if bytesmode:
data = [line.decode() for line in data]
assert data == expected
def test_isatty():
with hopper() as im:
container = ContainerIO.ContainerIO(im, 0, 0)
assert container.isatty() is False
def test_isatty(self):
im = hopper()
container = ContainerIO.ContainerIO(im, 0, 0)
self.assertEqual(container.isatty(), 0)
def test_isatty(self):
with hopper() as im:
container = ContainerIO.ContainerIO(im, 0, 0)
self.assertFalse(container.isatty())
def read_merged_file(file_name):
"""
Given the name of a merged png file this will read each image and
return a list of numpy arrays containing the images. This is the
slow way to read a merged file. Use the load module if you're looking
for a faster way to do this.
"""
try:
from PIL import Image, ContainerIO
except:
import Image
import ContainerIO
imgs = []
with open(file_name, 'rb') as in_file:
in_file.seek(0, 2)
end_pos = in_file.tell()
in_file.seek(0)
num_imgs = struct.unpack('i', in_file.read(4))[0]
it = 0
labels = []
while in_file.tell() < end_pos:
nbytes, minval, maxval = struct.unpack('iff', in_file.read(3 * 4))
if minval > maxval:
minval, maxval = maxval, minval
factor = (maxval - minval) / 255.0
curr_pos = in_file.tell()
# load image into np array
try:
img = np.asarray(
Image.open(
ContainerIO.ContainerIO(in_file, curr_pos, nbytes)))
except IOError:
in_file.seek(curr_pos)
labels.append(int(struct.unpack('f', in_file.read(4))[0] + .5))
curr_pos = in_file.tell()
img = np.asarray(
Image.open(
ContainerIO.ContainerIO(in_file, curr_pos, nbytes)))
# re-whiten the image
img = img * factor + minval
# add to list
imgs.append(img)
# seek past image
in_file.seek(curr_pos + nbytes)
it += 1
# ensure we reached end of file
curr_pos = in_file.tell()
in_file.seek(0, 2)
assert (curr_pos == in_file.tell())
# if these do not match throw warning
if it != num_imgs:
from warnings import warn
warn('File %s reported %d images but only had %d' %
(file_name, num_imgs, it))
return imgs, labels
