#!/usr/bin/env python
# coding: utf-8
# ******************************************************************************
# Copyright 2023 Brainchip Holdings Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ******************************************************************************
"""
Helper to load 10 samples of ImageNet-like data.
"""
__all__ = ["get_preprocessed_samples"]
import csv
import os
import numpy as np
from tensorflow.image import decode_jpeg
from tensorflow.io import read_file
from akida_models.imagenet import preprocessing
from akida_models.utils import fetch_file
[docs]
def get_preprocessed_samples(image_size=224, num_channels=3):
"""
Load and preprocess a 10 ImageNet-like images for testing.
Args:
image_size (int, optional): The target size for the images. Defaults to 224.
num_channels (int, optional): The number of channels in the images. Defaults to 3.
Returns:
x_test, labels_test (tuple): 4D and 1D numpy array of the preprocessed images and their
corresponding labels
"""
num_images = 10
file_path = fetch_file(
fname="imagenet_like.zip",
origin="https://data.brainchip.com/dataset-mirror/imagenet_like/imagenet_like.zip",
cache_subdir='datasets/imagenet_like',
extract=True)
data_folder = os.path.dirname(file_path)
x_test, x_test_files = _get_images(data_folder, num_images, image_size, num_channels)
labels_test = _get_labels(data_folder, num_images, x_test_files)
return x_test, labels_test
def _get_images(data_folder, num_images, image_size, num_channels):
"""
Load and preprocess ImageNet-like test images.
Args:
data_folder (str): Folder where images are located.
num_images (int): Number of images to load.
image_size (int): Target size for the images.
num_channels (int): Number of channels in the images.
Returns:
Tuple (`np.ndarray`, List[str]): Preprocessed images and corresponding file names.
"""
# Load images for test set
x_test_files = []
x_test = np.zeros((num_images, image_size, image_size, num_channels)).astype('uint8')
for idx in range(num_images):
test_file = 'image_' + str(idx + 1).zfill(2) + '.jpg'
x_test_files.append(test_file)
img_path = os.path.join(data_folder, test_file)
base_image = read_file(img_path)
image = decode_jpeg(base_image, channels=num_channels)
image = preprocessing.preprocess_image(image, (image_size, image_size))
x_test[idx, :, :, :] = np.expand_dims(image, axis=0)
return x_test, x_test_files
def _get_labels(data_folder, num_images, x_test_files):
"""
Parse labels file for ImageNet-like test samples.
Args:
data_folder (str): Folder where labels file is located.
num_images (int): Number of images.
x_test_files (List[str]): List of file names for test samples.
Returns:
labels_test (np.ndarray): NumPy array of labels for the test samples.
"""
# Parse labels file
fname = os.path.join(data_folder, 'labels_validation.txt')
validation_labels = dict()
with open(fname, newline='') as csvfile:
reader = csv.reader(csvfile, delimiter=' ')
for row in reader:
validation_labels[row[0]] = row[1]
# Get labels for the test set by index
labels_test = np.zeros(num_images)
for i in range(num_images):
labels_test[i] = int(validation_labels[x_test_files[i]])
return labels_test