接觸深度學(xué)習(xí)3個(gè)月以來，從當(dāng)初的小白零基礎(chǔ)學(xué)習(xí)，過程十分艱苦，看了幾章大牛 YoshuaBengio 寫的deep learning一書，粗略了解了基本常用的神經(jīng)網(wǎng)絡(luò)以及梯度更新策略，參數(shù)優(yōu)化，也了解以及簡(jiǎn)單的使用常用的深度學(xué)習(xí)開發(fā)框架caffe，tensorflow，theano，sklearn機(jī)器學(xué)習(xí)庫，目前keras比較火，所以使用keras來簡(jiǎn)單的進(jìn)行圖片識(shí)別分類。

數(shù)據(jù)集準(zhǔn)備：

看caffe博客的時(shí)候看到的數(shù)據(jù)集，然后就下載使用，數(shù)據(jù)集可以在最后下載。

數(shù)據(jù)集一共有5類圖片，一共500張，每類圖片100張，訓(xùn)練集400張，每類80張，測(cè)試集100張，每類20張

第一步：

數(shù)據(jù)集進(jìn)行處理：

使用opencv對(duì)圖片進(jìn)行處理，縮放圖片大小為128×128大小，通道為單通道灰度圖像

#coding:utf8

import os

import cv2.cv as cv

import cv2

# 遍歷指定目錄，顯示目錄下的所有文件名

width_scale = 192 #縮放尺寸寬度

height_scale = 128#縮放尺寸高度

write_path = "/home/zhanghao/data/classification/test_scale/"#要寫入的圖片路徑

#遍歷每一張圖片進(jìn)行處理

def eachFile(filepath):

pathDir = os.listdir(filepath)

for allDir in pathDir:

child = os.path.join('%s%s' % (filepath,allDir))

write_child = os.path.join('%s%s' % (write_path,allDir))

image = cv.LoadImage(child,0)

des_image = cv.CreateImage((width_scale,height_scale),image.depth,1)

cv.Resize(image,des_image,cv2.INTER_AREA)

# cv.ShowImage('afe',des_image)

cv.SaveImage(write_child,des_image)

# break

if __name__ == '__main__':

filePathC = "/home/zhanghao/data/classification/test/"

eachFile(filePathC)

第二步

把圖片集制作成keras識(shí)別的數(shù)據(jù)集

#制作數(shù)據(jù)集

def data_label(path,count):

data = np.empty((count,1,128,192),dtype = 'float32')#建立空的四維張量類型32位浮點(diǎn)

label = np.empty((count,),dtype = 'uint8')

i = 0

pathDir = os.listdir(path)

for each_image in pathDir:

all_path = os.path.join('%s%s' % (path,each_image))#路徑進(jìn)行連接

image = cv2.imread(all_path,0)

mul_num = re.findall(r"d",all_path)#尋找字符串中的數(shù)字，由于圖像命名為300.jpg 標(biāo)簽設(shè)置為0

num = int(mul_num[0])-3

# print num,each_image

# cv2.imshow("fad",image)

# print child

array = np.asarray(image,dtype='float32')

data[i,:,:,:] = array

label[i] = int(num)

i += 1

return data,label

第三步

構(gòu)建卷積神經(jīng)網(wǎng)絡(luò)進(jìn)行訓(xùn)練和測(cè)試

#構(gòu)建卷積神經(jīng)網(wǎng)絡(luò)

def cnn_model(train_data,train_label,test_data,test_label):

model = Sequential()

model.add(Convolution2D(

nb_filter = 12,

nb_row = 3,

nb_col = 3,

border_mode = 'valid',

dim_ordering = 'th',

input_shape = (1,128,192)))

model.add(Activation('relu'))#激活函數(shù)使用修正線性單元

model.add(MaxPooling2D(

pool_size = (2,2),

strides = (2,2),

border_mode = 'valid'))

model.add(Convolution2D(

24,

3,

3,

border_mode = 'valid',

dim_ordering = 'th'))

model.add(Activation('relu'))

#池化層 24×29×29

model.add(MaxPooling2D(

pool_size = (2,2),

strides = (2,2),

border_mode = 'valid'))

model.add(Convolution2D(

48,

3,

3,

border_mode = 'valid',

dim_ordering = 'th'))

model.add(Activation('relu'))

model.add(MaxPooling2D(

pool_size = (2,2),

strides =(2,2),

border_mode = 'valid'))

model.add(Flatten())

model.add(Dense(20))

model.add(Activation(LeakyReLU(0.3)))

model.add(Dropout(0.5))

model.add(Dense(20))

model.add(Activation(LeakyReLU(0.3)))

model.add(Dropout(0.4))

model.add(Dense(5,init = 'normal'))

model.add(Activation('softmax'))

adam = Adam(lr = 0.001)

model.compile(optimizer = adam,

loss = 'categorical_crossentropy',

metrics = ['accuracy'])

print '----------------training-----------------------'

model.fit(train_data,train_label,batch_size = 12,nb_epoch = 35,shuffle = True,show_accuracy = True,validation_split = 0.1)

print '----------------testing------------------------'

loss,accuracy = model.evaluate(test_data,test_label)

print ' test loss:',loss

print ' test accuracy',accuracy

第四步

調(diào)用上述函數(shù)進(jìn)行訓(xùn)練預(yù)測(cè)

train_path = '/home/zhanghao/data/classification/train_scale/'

test_path = '/home/zhanghao/data/classification/test_scale/'

train_count = getnum(train_path)

test_count = getnum(test_path)

train_data,train_label = data_label(train_path,train_count)

test_data,test_label = data_label(test_path,test_count)

train_label = np_utils.to_categorical(train_label,nb_classes = 5)

test_label = np_utils.to_categorical(test_label,nb_classes = 5)

cnn_model(train_data,train_label,test_data,test_label)

用到的頭文件

import re

import cv2

import os

import numpy as np

import cv2.cv as cv

from keras.models import Sequential

from keras.layers.core import Dense,Activation,Flatten

from keras.layers.convolutional import Convolution2D,MaxPooling2D

from keras.optimizers import Adam

from keras.layers.advanced_activations import LeakyReLU

from keras.utils import np_utils

cpu運(yùn)行，迭代50次，預(yù)測(cè)準(zhǔn)確率達(dá)到92%，還算可以的準(zhǔn)確率

具體實(shí)現(xiàn)代碼：https://github.com/zhanghao-JNU/keras-training

路漫漫其修遠(yuǎn)兮，吾將上下而求索

責(zé)任編輯：lq