OAK
Reputation: 3166
Keras - CNN - adjust dataset - remove biased class and data augmentation attempt
I have a a predicament with the model I am developing based on a popular dataset of skin-cancer images. I have to points I'd like some guidance on -
A.
The original dataset is over +10K images with which almost 7000 images belong to one of the seven classes. I've created a subset of 4948 random images with which I ran a function to convert the images into a list of lists - first list contains the image and the latter the class as well as dismiss any images that are of class (5 - the class with the +6800K images). Thought process was to normalise the distribution across the classes.
Re-running the original model with an output (Dense layer of 6 neurons instead of 7) - retrieves an error.
Am I missing a step to 'indicate' to the model that there are only six possible classes? The model runs only when the output layer has seven neurons.
error:
Train on 1245 samples, validate on 312 samples
Epoch 1/30
---------------------------------------------------------------------------
InvalidArgumentError Traceback (most recent call last)
<ipython-input-138-8a3b40a69e37> in <module>
25 metrics=["accuracy"])
26
---> 27 model.fit(X_train, y_train, batch_size=32, epochs=30, validation_split=0.2)
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/training.py in fit(self, x, y, batch_size, epochs, verbose, callbacks, validation_split, validation_data, shuffle, class_weight, sample_weight, initial_epoch, steps_per_epoch, validation_steps, validation_freq, max_queue_size, workers, use_multiprocessing, **kwargs)
778 validation_steps=validation_steps,
779 validation_freq=validation_freq,
--> 780 steps_name='steps_per_epoch')
781
782 def evaluate(self,
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/training_arrays.py in model_iteration(model, inputs, targets, sample_weights, batch_size, epochs, verbose, callbacks, val_inputs, val_targets, val_sample_weights, shuffle, initial_epoch, steps_per_epoch, validation_steps, validation_freq, mode, validation_in_fit, prepared_feed_values_from_dataset, steps_name, **kwargs)
361
362 # Get outputs.
--> 363 batch_outs = f(ins_batch)
364 if not isinstance(batch_outs, list):
365 batch_outs = [batch_outs]
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/backend.py in __call__(self, inputs)
3290
3291 fetched = self._callable_fn(*array_vals,
-> 3292 run_metadata=self.run_metadata)
3293 self._call_fetch_callbacks(fetched[-len(self._fetches):])
3294 output_structure = nest.pack_sequence_as(
/anaconda3/lib/python3.7/site-packages/tensorflow/python/client/session.py in __call__(self, *args, **kwargs)
1456 ret = tf_session.TF_SessionRunCallable(self._session._session,
1457 self._handle, args,
-> 1458 run_metadata_ptr)
1459 if run_metadata:
1460 proto_data = tf_session.TF_GetBuffer(run_metadata_ptr)
InvalidArgumentError: Received a label value of 6 which is outside the valid range of [0, 6). Label values: 1 1 2 4 2 1 2 1 2 1 2 2 4 2 2 1 3 1 4 6 0 2 4 2 0 4 2 4 4 0 2 4
[[{{node loss_15/activation_63_loss/SparseSoftmaxCrossEntropyWithLogits/SparseSoftmaxCrossEntropyWithLogits}}]]
B.
I'm attempting to add Data Augmentation as the dataset is relatively small taking into account the number of classes and the sparsity of the images across the classes. Once I try to run the generator I receive the error message below which suggests that there is something wrong with one of the variables in the validation_data tuple. I cannot understand what the issue is.
Example values of the test set look like:
[[[[0.41568627]
[0.4 ]
[0.43137255]
...
[0.54509804]
[0.54901961]
[0.54509804]]
[[0.42352941]
[0.43137255]
[0.43921569]
...
[0.56078431]
[0.54117647]
[0.55294118]]
[[0.41960784]
[0.41960784]
[0.45490196]
...
[0.51764706]
[0.57254902]
[0.50588235]]
...
[[0.30980392]
[0.36470588]
[0.36470588]
...
[0.47058824]
[0.44705882]
[0.41960784]]
[[0.29803922]
[0.31764706]
[0.34509804]
...
[0.45098039]
[0.43921569]
[0.4 ]]
[[0.25882353]
[0.30196078]
[0.31764706]
...
[0.45490196]
[0.42745098]
[0.36078431]]]
[[[0.60784314]
[0.59215686]
[0.56862745]
...
[0.59607843]
[0.63921569]
[0.63529412]]
[[0.6627451 ]
[0.63137255]
[0.62352941]
...
[0.67843137]
[0.60784314]
[0.63529412]]
[[0.62745098]
[0.65098039]
[0.6 ]
...
[0.61568627]
[0.63921569]
[0.67058824]]
...
[[0.62352941]
[0.6 ]
[0.59607843]
...
[0.6627451 ]
[0.71372549]
[0.6745098 ]]
[[0.61568627]
[0.58431373]
[0.61568627]
...
[0.67058824]
[0.65882353]
[0.68235294]]
[[0.61176471]
[0.60392157]
[0.61960784]
...
[0.65490196]
[0.6627451 ]
[0.66666667]]]]
[2, 1, 4, 4, 2]
Error:
Epoch 1/10
1/155 [..............................] - ETA: 11s - loss: 1.7916 - acc: 0.3000
---------------------------------------------------------------------------
InvalidArgumentError Traceback (most recent call last)
<ipython-input-139-8f19a958861f> in <module>
12 history = model.fit_generator(trainAug.flow(X_train, y_train, batch_size=batch_size)
13 ,epochs = 10, validation_data = (X_test, y_test),
---> 14 steps_per_epoch= X_train.shape[0]// batch_size
15 )
16 #epochs = epochs, validation_data = (X_test, y_test),
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/training.py in fit_generator(self, generator, steps_per_epoch, epochs, verbose, callbacks, validation_data, validation_steps, validation_freq, class_weight, max_queue_size, workers, use_multiprocessing, shuffle, initial_epoch)
1431 shuffle=shuffle,
1432 initial_epoch=initial_epoch,
-> 1433 steps_name='steps_per_epoch')
1434
1435 def evaluate_generator(self,
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/training_generator.py in model_iteration(model, data, steps_per_epoch, epochs, verbose, callbacks, validation_data, validation_steps, validation_freq, class_weight, max_queue_size, workers, use_multiprocessing, shuffle, initial_epoch, mode, batch_size, steps_name, **kwargs)
262
263 is_deferred = not model._is_compiled
--> 264 batch_outs = batch_function(*batch_data)
265 if not isinstance(batch_outs, list):
266 batch_outs = [batch_outs]
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/training.py in train_on_batch(self, x, y, sample_weight, class_weight, reset_metrics)
1173 self._update_sample_weight_modes(sample_weights=sample_weights)
1174 self._make_train_function()
-> 1175 outputs = self.train_function(ins) # pylint: disable=not-callable
1176
1177 if reset_metrics:
/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/backend.py in __call__(self, inputs)
3290
3291 fetched = self._callable_fn(*array_vals,
-> 3292 run_metadata=self.run_metadata)
3293 self._call_fetch_callbacks(fetched[-len(self._fetches):])
3294 output_structure = nest.pack_sequence_as(
/anaconda3/lib/python3.7/site-packages/tensorflow/python/client/session.py in __call__(self, *args, **kwargs)
1456 ret = tf_session.TF_SessionRunCallable(self._session._session,
1457 self._handle, args,
-> 1458 run_metadata_ptr)
1459 if run_metadata:
1460 proto_data = tf_session.TF_GetBuffer(run_metadata_ptr)
InvalidArgumentError: Received a label value of 6 which is outside the valid range of [0, 6). Label values: 0 1 6 4 2 4 2 0 1 2
[[{{node loss_15/activation_63_loss/SparseSoftmaxCrossEntropyWithLogits/SparseSoftmaxCrossEntropyWithLogits}}]]
Code:
import tensorflow as tf
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense, Dropout, Activation, Flatten, Conv2D, MaxPooling2D
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import sys
import os
import cv2
DATA_DIR = "/Users/namefolder/PycharmProjects/skin-cancer/HAM10000_images_part_1"
metadata = pd.read_csv(os.path.join(DATA_DIR, 'HAM10000_metadata.csv'))
lesion_type_dict = {'nv': 'Melanocytic nevi',
'mel': 'Melanoma',
'bkl': 'Benign keratosis-like lesions ',
'bcc': 'Basal cell carcinoma',
'akiec': 'Actinic keratoses',
'vasc': 'Vascular lesions',
'df': 'Dermatofibroma'}
metadata['cell_type'] = metadata['dx'].map(lesion_type_dict.get)
metadata['dx_code'] = pd.Categorical(metadata['dx']).codes
# save array of image-id and diagnosis-type (categorical)
metadata = metadata[['image_id', 'dx', 'dx_type', 'dx_code']]
training_data = []
IMG_SIZE=50
# preparing training data
def creating_training_data(path):
for img in os.listdir(path):
try:
img_array = cv2.imread(os.path.join(path, img), cv2.IMREAD_GRAYSCALE)
new_array = cv2.resize(img_array, (IMG_SIZE, IMG_SIZE))
for index, row in metadata.iterrows():
if (img == row['image_id']+'.jpg') & (row['dx_code'] != 5):
try:
training_data.append([new_array, row['dx_code']])
except Exception as ee:
pass
except Exception as e:
pass
return training_data
training_data = creating_training_data(DATA_DIR)
import random
random.shuffle(training_data)
# Splitting data into X features and Y label
X_train = []
y_train = []
for features, label in training_data:
X_train.append(features)
y_train.append(label)
# Reshaping of the data - required by Tensorflow and Keras (*necessary step of deep-learning using these repos)
X_train = np.array(X_train).reshape(-1, IMG_SIZE, IMG_SIZE, 1)
# Normalize data - to reduce processing requirements
X_train = X_train/255.0
# model configuration
model = Sequential()
model.add(Conv2D(64, (3,3), input_shape = X_train.shape[1:]))
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(Dense(6))
model.add(Activation("softmax"))
model.compile(loss="mean_squared_error",
optimizer="adam",
metrics=["accuracy"])
# Data Augmentation - Repo enabler
from keras.preprocessing.image import ImageDataGenerator
from keras.callbacks import ReduceLROnPlateau
# initialize the training training data augmentation object
trainAug = ImageDataGenerator(
rescale=1 / 255.0,
rotation_range=20,
zoom_range=0.05,
width_shift_range=0.05,
height_shift_range=0.05,
shear_range=0.05,
horizontal_flip=True,
fill_mode="nearest")
# initialize the validation (and testing) data augmentation object
valAug = ImageDataGenerator(rescale=1 / 255.0)
#set a leraning rate annealer
learning_rate_reduction = ReduceLROnPlateau(monitor='val_acc',
patience=3,
verbose=1,
factor=0.5,
min_lr=0.00001)
#Augmented Images model development
)
trainAug.fit(X_train)
#Fit the model
epochs = 10
batch_size= 10
history = model.fit_generator(trainAug.flow(X_train, y_train, batch_size=batch_size),epochs = 10, validation_data = (X_test, y_test), steps_per_epoch= X_train.shape[0]// batch_size)
Upvotes: 0
Views: 907
Answers (1)
Daniel Möller
Reputation: 86630
Initially you had 7 labels: your code was then expecting labels 0, 1, 2, 3, 4, 5, 6
You removed label 5 from the dataset, ok. Now you have 6 labels in total.
Your code is expecting: 0, 1, 2, 3, 4, 5
But what you have in your data is: 0, 1, 2, 3, 4, 6
After removing the label 5, you need to transform the labels 6 into 5.
Something in the lines of:
if (img == row['image_id']+'.jpg') & (row['dx_code'] > 5):
try:
training_data.append([new_array, row['dx_code'] - 1])
except Exception as ee:
pass
elif (img == row['image_id']+'.jpg') & (row['dx_code'] < 5):
try:
training_data.append([new_array, row['dx_code']])
except Exception as ee:
pass
Upvotes: 2
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