predict juggling patterns using keras

keras for juggling

import numpy as np, os, cv2
from keras.utils import to_categorical
from keras.models import load_model

#reads images from folder (images must be labeled 0.png, 1.png, etc...)
def read_from_folder(folder, pattern, image_number, stop):
    images = []
    while image_number < stop:
        path = folder + pattern + '/' + str(image_number) + '.png'
        img = cv2.imread(path, 0)
        images.append(img)
        image_number+=1
    return images

#flattens a list of images, returns an array range 0,1
def flatten(dimData, images):
    images = np.array(images)
    images = images.reshape(len(images), dimData)
    images = images.astype('float32')
    images /=255
    return images

#-------------------get training data and training labels---------------
train_start, train_stop = 120,800 #only 4GB RAM :(
test_start, test_stop = 800,1200
folder = '/home/stephen/Desktop/juggling/'
#the perprocessed images are stored in 5 folders
patterns = ['cascade', '423', 'columns', '2inlh', '2inrh']

#Training Images
train_images = []
for pattern in patterns: train_images += read_from_folder(folder, pattern, train_start, train_stop)
#image dimentions
h,w = train_images[0].shape
dimData = np.prod(h*w)
#list of images --> array of flattened iamges
train_data = flatten(dimData, train_images)

#make training_labels
train_labels = []
for pattern in patterns:
    for i in range(train_stop - train_start): train_labels.append(patterns.index(pattern))
train_labels = np.array(train_labels)
# integer --> categorical data
train_labels_one_hot = to_categorical(train_labels)

#-----------------get testing data and testing labels-------------------
#Test images
test_images = []
for pattern in patterns: test_images += read_from_folder(folder, pattern, test_start, test_stop)
#list of images --> array of flattened iamges
test_data = flatten(dimData, test_images)

#make test_labels
test_labels = []
for pattern in patterns:
    for i in range(test_stop - test_start): test_labels.append(patterns.index(pattern))
test_labels = np.array(test_labels)
# integer --> categorical data
test_labels_one_hot = to_categorical(test_labels)

#------------------make keras model--------------------------------
# Find the unique numbers from the train labels
classes = np.unique(train_labels)
nClasses = len(classes)

from keras.models import Sequential
from keras.layers import Dense
model = Sequential()
model.add(Dense(512, activation='relu', input_shape=(dimData,)))
model.add(Dense(512, activation='relu'))
model.add(Dense(nClasses, activation='softmax'))
model.compile(optimizer='rmsprop', loss='categorical_crossentropy', metrics=['accuracy'])
#fit model - this is where the magic happens
history = model.fit(train_data, train_labels_one_hot, batch_size=256, epochs=2, verbose=1, 
                   validation_data=(test_data, test_labels_one_hot))
#test model
[test_loss, test_acc] = model.evaluate(test_data, test_labels_one_hot)
print("Evaluation result on Test Data : Loss = {}, accuracy = {}".format(test_loss, test_acc))
#save model
model.save('/home/stephen/Desktop/juggling/my_model.h5')