Develop Reference

Getting very poor accuracy on stanford_dogs dataset

I'm trying to train a model on the stanford_dogs dataset to classify 120 dog breeds but my code is acting strange.
I downloaded the image data from http://vision.stanford.edu/aditya86/ImageNetDogs/images.tar
Then ran the following code to split each folder of the breeds into training and testing folders:
dataset_dict = {}
source_path = 'C:/Users/visha/Downloads/stanford_dogs/dataset'
dir_root = os.getcwd()
dataset_folders = [x for x in os.listdir(os.path.join(dir_root, source_path)) if os.path.isdir(os.path.join(dir_root, source_path, x))]
for category in dataset_folders:
dataset_dict[category] = {'source_path': os.path.join(dir_root, source_path, category),
'train_path': create_folder(new_path='C:/Users/visha/Downloads/stanford_dogs/train',
folder_type='train',
data_class=category),
'validation_path': create_folder(new_path='C:/Users/visha/Downloads/stanford_dogs/validation',
folder_type='validation',
data_class=category)}
dataset_folders = [x for x in os.listdir(os.path.join(dir_root, source_path)) if os.path.isdir(os.path.join(dir_root, source_path, x))]
for key in dataset_dict:
print("Splitting Category {} ...".format(key))
split_data(source_path=dataset_dict[key]['source_path'],
train_path=dataset_dict[key]['train_path'],
validation_path=dataset_dict[key]['validation_path'],
split_size=0.7)
I fed the images through the network after some image augmentation and used sigmoid activation in the final layer and categorical_crossentropy loss.
import tensorflow as tf
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from tensorflow.keras.optimizers import RMSprop
model = tf.keras.models.Sequential([
tf.keras.layers.Conv2D(16, (3, 3), activation='relu', input_shape=(150, 150, 3)),
tf.keras.layers.MaxPooling2D(2, 2),
tf.keras.layers.Conv2D(32, (3, 3), activation='relu'),
tf.keras.layers.MaxPooling2D(2, 2),
tf.keras.layers.Conv2D(64, (3, 3), activation='relu'),
tf.keras.layers.MaxPooling2D(2, 2),
tf.keras.layers.Flatten(),
tf.keras.layers.Dense(512, activation='relu'),
tf.keras.layers.Dense(120, activation='softmax')
])
model.compile(optimizer='rmsprop',
loss='categorical_crossentropy',
metrics=['accuracy'])
TRAINING_DIR = 'C:/Users/visha/Downloads/stanford_dogs/train'
train_datagen = ImageDataGenerator(rescale=1./255,rotation_range=40,width_shift_range=0.2,height_shift_range=0.2,
shear_range=0.2,zoom_range=0.2,horizontal_flip=True,fill_mode='nearest')
train_generator = train_datagen.flow_from_directory(TRAINING_DIR,
batch_size=10,
class_mode='categorical',
target_size=(150, 150))
VALIDATION_DIR = 'C:/Users/visha/Downloads/stanford_dogs/validation'
validation_datagen = ImageDataGenerator(rescale=1./255, rotation_range=40,width_shift_range=0.2, height_shift_range=0.2,
shear_range=0.2,zoom_range=0.2,horizontal_flip=True,fill_mode='nearest')
validation_generator = validation_datagen.flow_from_directory(VALIDATION_DIR,
batch_size=10,
class_mode='categorical',
target_size=(150, 150))
history = model.fit(train_generator,
epochs=10,
verbose=1,
validation_data=validation_generator)
But the code is not working as intended. The val_accuracy after 10 epochs is something like 4.756.

For validation data you should not do any image augmentation, just do rescale. In validation flow_from_directory set shuffle=False. Be advised that the Stanford Dog Data set is very difficult. To achieve a reasonable degree of accuracy you will need a much more complex model. I recommend you consider transfer learning using the Mobilenet model. The code below shows how to do that.
base_model=tf.keras.applications.mobilenet.MobileNet( include_top=False,
input_shape=(150,150,3) pooling='max', weights='imagenet',dropout=.4)
x=base_model.output
x=keras.layers.BatchNormalization(axis=-1, momentum=0.99, epsilon=0.001 )(x)
x = Dense(1024, activation='relu')(x)
x=Dropout(rate=.3, seed=123)(x)
output=Dense(120, activation='softmax')(x)
model=Model(inputs=base_model.input, outputs=output)
model.compile(Adamax(lr=.001),loss='categorical_crossentropy',metrics=
['accuracy'] )
I forgot to mention that Mobilenet was trained on Images with pixel values in the range -1 to +1. So in ImageDataGenerator include the code
preprocessing_function=tf.keras.applications.mobilenet.preprocess_input
this scales the pixels so you do not need the code
rescale=1./255
or alternatively set
rescale=1/157.5-1
which will rescale the values between -1 and +1

How to fix 'ValueError: Empty Training Data' error in tensorflow

I am new to tensorflow and keras. I am trying to train a model to identify different images for rock paper and scissors. I am using an online tutorial for that and they have provided me with a google collab worksheet. When I train the model on google collab everything works fine but if I try training the model on my machine, it gives me this error:
ValueValueError: Empty training data
I have tried changing the batch size and also tried tried changing the amount of images in the dataset but it doesnt help(And it shouldn't).
Here is my code:
###### ROCK PAPER SISSORS #######
import os
import numpy as np
import cv2
import tensorflow as tf
import keras_preprocessing
from keras_preprocessing import image
from keras_preprocessing.image import ImageDataGenerator
import matplotlib.pyplot as plt
# import matplotlib.image as mpimg
# Provide the path to the directory of the classes
rock_dir = os.path.join('/media/visheshchanana/New Volume/Projects/datasets/RPS/rps/rock')
paper_dir = '/media/visheshchanana/New Volume/Projects/datasets/RPS/rps/paper'
scissors_dir = '/media/visheshchanana/New Volume/Projects/datasets/RPS/rps/scissors'
rock_files = os.listdir(rock_dir)
# print(rock_files[:10])
# ​
paper_files = os.listdir(paper_dir)
# print(paper_files[:10])
# ​
scissors_files = os.listdir(scissors_dir)
# # print(scissors_files[:10])
# Use the augmentation tool to change the augmentation of the images so that we can have a better classifier
TRAINING_DIR = "/media/visheshchanana/New Volume/Projects/datasets/RPS/rps"
training_datagen = ImageDataGenerator(
rescale = 1./255,
rotation_range=40,
width_shift_range=0.2,
height_shift_range=0.2,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True,
fill_mode='nearest')
# Provide the path to the validation dataset
VALIDATION_DIR = "/media/visheshchanana/New Volume/Projects/datasets/RPS/RPS_validation"
validation_datagen = ImageDataGenerator(rescale = 1./255)
train_generator = training_datagen.flow_from_directory(
TRAINING_DIR,
target_size=(150,150),
class_mode='categorical'
)
validation_generator = validation_datagen.flow_from_directory(
VALIDATION_DIR,
target_size=(150,150),
class_mode='categorical'
)
model = tf.keras.models.Sequential([
# Note the input shape is the desired size of the image 150x150 with 3 bytes color
# This is the first convolution
tf.keras.layers.Conv2D(64, (3,3), activation='relu', input_shape=(150, 150, 3)),
tf.keras.layers.MaxPooling2D(2, 2),
# The second convolution
tf.keras.layers.Conv2D(64, (3,3), activation='relu'),
tf.keras.layers.MaxPooling2D(2,2),
# The third convolution
tf.keras.layers.Conv2D(128, (3,3), activation='relu'),
tf.keras.layers.MaxPooling2D(2,2),
# The fourth convolution
tf.keras.layers.Conv2D(128, (3,3), activation='relu'),
tf.keras.layers.MaxPooling2D(2,2),
# Flatten the results to feed into a DNN
tf.keras.layers.Flatten(),
tf.keras.layers.Dropout(0.5),
# 512 neuron hidden layer
tf.keras.layers.Dense(512, activation='relu'),
tf.keras.layers.Dense(3, activation='softmax')
])
model.summary()
model.compile(loss = 'categorical_crossentropy', optimizer='rmsprop', metrics=['accuracy'])
history = model.fit_generator(train_generator, epochs=5, validation_data = validation_generator, verbose = 1)
The dataset is the same as used in the google collab. I can't figure out the reason behind this error.

There might be other reasons for this error, but I realized that I had a batch size that was greater than my sample size.

I had the same problem. My model trains and gives this error (ValueValueError: Empty training data) at the end of the first epoch. I figured out that it was because there was no data in the validation path.

Check if steps_per_epoch is not set to 0 (e.g. because of integer division)

Get indices of incorrect predictions keras

The used CNN has been displayed already in Image prediction using Keras but I want to follow another target. Im apparently using the following CNN of the KERAS tutorial "Building powerful image classification models using very little data" (Francois Chollet). I would like to get the false predictions as an additional Output to see if the Images are too difficult to classify of if the CNN has Problems - is there any easy way to include that in the code?
from keras.preprocessing.image import ImageDataGenerator
datagen = ImageDataGenerator(
rotation_range=40,
width_shift_range=0.2,
height_shift_range=0.2,
rescale=1./255,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True,
fill_mode='nearest')
from keras.preprocessing.image import ImageDataGenerator,
array_to_img, img_to_array, load_img
datagen = ImageDataGenerator(
rotation_range=40,
width_shift_range=0.2,
height_shift_range=0.2,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True,
fill_mode='nearest')
img = load_img('data/train/cats/cat.0.jpg') # this is a PIL image x =
img_to_array(img) # this is a Numpy array with shape (3, 150, 150) x
= x.reshape((1,) + x.shape) # this is a Numpy array with shape (1, 3, 150, 150)
i = 0 for batch in datagen.flow(x, batch_size=1,
save_to_dir='preview', save_prefix='cat', save_format='jpeg'):
i += 1
if i > 20:
break # otherwise the generator would loop indefinitely
from keras.models import Sequential from keras.layers import Conv2D,
MaxPooling2D from keras.layers import Activation, Dropout, Flatten,
Dense
model = Sequential() model.add(Conv2D(32, (3, 3), input_shape=(3, 150,
150))) model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Conv2D(32, (3, 3))) model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Conv2D(64, (3, 3))) model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Flatten()) # this converts our 3D feature maps to 1D
feature vectors model.add(Dense(64)) model.add(Activation('relu'))
model.add(Dropout(0.5)) model.add(Dense(1))
model.add(Activation('sigmoid'))
model.compile(loss='binary_crossentropy',
optimizer='rmsprop',
metrics=['accuracy']) batch_size = 16
train_datagen = ImageDataGenerator(
rescale=1./255,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True)
test_datagen = ImageDataGenerator(rescale=1./255)
train_generator = train_datagen.flow_from_directory(
'data/train', # this is the target directory
target_size=(150, 150), # all images will be resized to 150x150
batch_size=batch_size,
class_mode='binary') # since we use binary_crossentropy loss, we need binary labels
validation_generator = test_datagen.flow_from_directory(
'data/validation',
target_size=(150, 150),
batch_size=batch_size,
class_mode='binary')
model.fit_generator(
train_generator,
steps_per_epoch=2000 // batch_size,
epochs=50,
validation_data=validation_generator,
validation_steps=800 // batch_size)
model.save_weights('first_try.h5')

Python Keras - How to input custom image?

from keras import *
import os
import numpy as np
from keras.models import Sequential
from keras.layers import Activation, Dropout, Flatten, Dense
from keras.preprocessing.image import ImageDataGenerator
from keras.layers import Convolution2D, MaxPooling2D, ZeroPadding2D
from keras import optimizers
# Collecting data:
img_width, img_height = 150, 150
training_data_dir = "train"
testing_data_dir = "test"
batch_size = 16
# prepare data augmentation configuration
train_datagen = ImageDataGenerator(
rescale=1. / 255,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True)
test_datagen = ImageDataGenerator(rescale=1. / 255)
train_generator = train_datagen.flow_from_directory(
training_data_dir,
target_size=(img_height, img_width),
batch_size=batch_size,
class_mode='binary')
validation_generator = test_datagen.flow_from_directory(
testing_data_dir,
target_size=(img_height, img_width),
batch_size=batch_size,
class_mode='binary')
# Building model:
model = Sequential()
model.add(Convolution2D(32, (3, 3), input_shape=(img_width, img_height,3)))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Convolution2D(32, (3, 3)))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Convolution2D(64, (3, 3)))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Flatten())
model.add(Dense(64))
model.add(Activation('relu'))
model.add(Dropout(0.5))
model.add(Dense(1))
model.add(Activation('sigmoid'))
model.compile(loss="binary_crossentropy",
optimizer="rmsprop",
metrics=["accuracy"])
# Training model:
nb_epoch = 1
nb_train_samples = 2048
nb_validation_samples = 832
model.fit_generator(
train_generator,
samples_per_epoch=nb_train_samples,
epochs=nb_epoch,
validation_data=validation_generator,
validation_steps=nb_validation_samples,
steps_per_epoch=64)
My code here creates a neural network for image classification based on pictures it is trained on, I have searched all over the internet but one thing I can't understand is how to input my own image file to test against the network and for it to print out the output. For example if the net was for classifying dogs and cats, I'm not sure on how to code the bit where I input a jpg/png file for a dog or a cat and the program to output which class it is. Help please?

You call the model's predict method. https://keras.io/models/model/#predict

Python Keras Image Recognition using Tensorflow model.predict returns [[0.]]

I've been following the tutorial here to process images of cats, and see if a specific picture contains a cat. The data set I use is here. Is there something missing in the way I read in an image for testing? In my results from model.predict(filePath), I always get the value '[[0.]]' when reading an image containing a cat. The train and validation sets seem to work correctly. I am only having issues reading in an image. (Source code is copied from here)
from keras.preprocessing.image import ImageDataGenerator
from keras.models import Sequential
from keras.layers import Conv2D, MaxPooling2D
from keras.layers import Activation, Dropout, Flatten, Dense
from keras import backend as K
import numpy as np
from keras.preprocessing import image
# dimensions of our images.
img_width, img_height = 150, 150
train_data_dir = 'data/train'
validation_data_dir = 'data/validation'
nb_train_samples = 2000
nb_validation_samples = 800
epochs = 50
batch_size = 16
if K.image_data_format() == 'channels_first':
input_shape = (3, img_width, img_height)
else:
input_shape = (img_width, img_height, 3)
model = Sequential()
model.add(Conv2D(32, (3, 3), input_shape=input_shape))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Conv2D(32, (3, 3)))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Conv2D(64, (3, 3)))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Flatten())
model.add(Dense(64))
model.add(Activation('relu'))
model.add(Dropout(0.5))
model.add(Dense(1))
model.add(Activation('sigmoid'))
model.compile(loss='binary_crossentropy',
optimizer='rmsprop',
metrics=['accuracy'])
# this is the augmentation configuration we will use for training
train_datagen = ImageDataGenerator(
rescale=1. / 255,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True)
# this is the augmentation configuration we will use for testing:
# only rescaling
test_datagen = ImageDataGenerator(rescale=1. / 255)
train_generator = train_datagen.flow_from_directory(
train_data_dir,
target_size=(img_width, img_height),
batch_size=batch_size,
class_mode='binary')
validation_generator = test_datagen.flow_from_directory(
validation_data_dir,
target_size=(img_width, img_height),
batch_size=batch_size,
class_mode='binary')
model.fit_generator(
train_generator,
steps_per_epoch=nb_train_samples // batch_size,
epochs=epochs,
validation_data=validation_generator,
validation_steps=nb_validation_samples // batch_size)
model.save_weights('first_try.h5')
def _LoadImage(filePath):
test_image = image.load_img(filePath, target_size = (150,150))
test_image = image.img_to_array(test_image)
test_image = np.expand_dims(test_image, axis=0)
return test_image
test_this = _LoadImage('test.jpg')
result = model.predict(test_this)
print(result)

Looks like "0" is the label of cat ("The training archive contains 25,000 images of dogs and cats. Train your algorithm on these files and predict the labels for test1.zip (1 = dog, 0 = cat)."), so your model predictions seem to be correct. Remember that the model is predicting (cat and dog) labels and not what class string you might be corresponding with the labels yourself. Try feeding an image of a dog and you should get "1" in return.