data-science-ipython-notebooks/deep-learning/keras-tutorial/deep_learning_models/imagenet_utils.py
2017-08-26 08:25:13 -04:00

44 lines
1.2 KiB
Python

import numpy as np
import json
from keras.utils.data_utils import get_file
from keras import backend as K
CLASS_INDEX = None
CLASS_INDEX_PATH = 'https://s3.amazonaws.com/deep-learning-models/image-models/imagenet_class_index.json'
def preprocess_input(x, dim_ordering='default'):
if dim_ordering == 'default':
dim_ordering = K.image_dim_ordering()
assert dim_ordering in {'tf', 'th'}
if dim_ordering == 'th':
x[:, 0, :, :] -= 103.939
x[:, 1, :, :] -= 116.779
x[:, 2, :, :] -= 123.68
# 'RGB'->'BGR'
x = x[:, ::-1, :, :]
else:
x[:, :, :, 0] -= 103.939
x[:, :, :, 1] -= 116.779
x[:, :, :, 2] -= 123.68
# 'RGB'->'BGR'
x = x[:, :, :, ::-1]
return x
def decode_predictions(preds):
global CLASS_INDEX
assert len(preds.shape) == 2 and preds.shape[1] == 1000
if CLASS_INDEX is None:
fpath = get_file('imagenet_class_index.json',
CLASS_INDEX_PATH,
cache_subdir='models')
CLASS_INDEX = json.load(open(fpath))
indices = np.argmax(preds, axis=-1)
results = []
for i in indices:
results.append(CLASS_INDEX[str(i)])
return results