Using the the program at this link, https://leon.bottou.org/projects/infimnist, I generated some data.
As far as i can tell it is in some sort of binary format:
b"\x00\x00\x08\x01\x00\x00'\x10\x07\x02\x01\x00\x04\x01\x04\t\x05 ...
I need to extract labels and pictures from two datasets like this, generated with:
https://leon.bottou.org/projects/infimnist
with open("test10k-labels", "rb") as binary_file:
data = binary_file.read()
print(data)
>>> b"\x00\x00\x08\x01\x00\x00'\x10\x07\x02\x01\x00\x04\x01\x04\t\x05 ...
b"\x00\x00\x08\x01 ...".decode('ascii')
>>> "\x00\x00\x08\x01 ..."
I also tried the binascii package, but it did not work.
Thankful for any help!
To create the dataset i am speaking download the package from the following link: https://leon.bottou.org/projects/infimnist.
$ cd dir_of_folder
$ make
Then I took the path of the resulting infimnist executable that pops up and:
$ app_path lab 10000 69999 > mnist60k-labels-idx1-ubyte
This should place the file i used in the folder.
The command after app_path can be replaced by any other command he lists on the side.
It works! Using some numpy functions the images can be returned to their normal orientation.
# for the labels
with open(path, "rb") as binary_file:
y_train = np.array(array("B", binary_file.read()))
# for the images
with open("images path", "rb") as binary_file:
images = []
emnistRotate = True
magic, size, rows, cols = struct.unpack(">IIII", binary_file.read(16))
if magic != 2051:
raise ValueError('Magic number mismatch, expected 2051,''got {}'.format(magic))
for i in range(size):
images.append([0] * rows * cols)
image_data = array("B", binary_file.read())
for i in range(size):
images[i][:] = image_data[i * rows * cols:(i + 1) * rows * cols]
# for some reason EMNIST is mirrored and rotated
if emnistRotate:
x = image_data[i * rows * cols:(i + 1) * rows * cols]
subs = []
for r in range(rows):
subs.append(x[(rows - r) * cols - cols:(rows - r)*cols])
l = list(zip(*reversed(subs)))
fixed = [item for sublist in l for item in sublist]
images[i][:] = fixed
x = []
for image in images:
x.append(np.rot90(np.flip(np.array(image).reshape((28,28)), 1), 1))
x_train = np.array(x)
Crazy solution for such a simple thing :)
Ok, so looking at the python-mnist
source, it seems the correct way to unpack the binary format is as follows:
from array import array
with open("test10k-labels", "rb") as binary_file:
magic, size = struct.unpack(">II", file.read(8))
if magic != 2049:
raise ValueError("Magic number mismatch, expected 2049,got{}".format(magic))
labels = array("B", binary_file.read())
print(labels)
update
So I haven't tested this extensively, but the following code should work. It was taken and modified from the aforementioned python-mnist
see source
from array import array
import struct
with open("mnist8m-patterns-idx3-ubyte", "rb") as binary_file:
images = []
emnistRotate = True
magic, size, rows, cols = struct.unpack(">IIII", binary_file.read(16))
if magic != 2051:
raise ValueError('Magic number mismatch, expected 2051,''got {}'.format(magic))
for i in range(size):
images.append([0] * rows * cols)
image_data = array("B", binary_file.read())
for i in range(size):
images[i][:] = image_data[i * rows * cols:(i + 1) * rows * cols]
# for some reason EMNIST is mirrored and rotated
if emnistRotate:
x = image_data[i * rows * cols:(i + 1) * rows * cols]
subs = []
for r in range(rows):
subs.append(x[(rows - r) * cols - cols:(rows - r)*cols])
l = list(zip(*reversed(subs)))
fixed = [item for sublist in l for item in sublist]
images[i][:] = fixed
print(images)
previous answer:
You can use the python-mnist
library:
from mnist import MNIST
mndata = MNIST('./data')
images, labels = mndata.load_training()