【机器学习14】笑脸识别,口罩识别

    技术2026-03-27  17

    【机器学习14】笑脸识别,口罩识别

    1.概念

    1.HOG:(方向梯度直方图)

    1.分割图像

    overlap和non-overlap两种分割策略。overlap指的是分割出的区块(patch)互相交叠,有重合的区域。non-overlap指的是区块不交叠,没有重合的区域。

    2.计算每个分割区块的方向梯度直方图

    利用任意一种梯度算子,例如:sobel,laplacian等,对该patch进行卷积,计算得到每个像素点处的梯度方向和幅值。将360度(2*PI)根据需要分割成若干个bin,例如:分割成12个bin,每个bin包含30度,整个直方图包含12维,即12个bin。然后根据每个像素点的梯度方向,利用双线性内插法将其幅值累加到直方图中。

    3.组合特征

    将从每个patch中提取出的“小”HOG特征首尾相连,组合成一个大的一维向量,这就是最终的图像特征。可以将这个特征送到分类器中训练了。例如:有44=16个patch,每个patch提取12维的小HOG,那么最终特征的长度就是:1612=192维。

    2.Dlib:

    dlib中是先检测都人脸,然后把人脸通过Resnet生成一个128维的向量,Resnet有几种不同深度的结构.dlib使用的是34层的网络.

    resnet34的最后一层是fc 1000,就是1000个神经元.resnet如何生成128维的向量的呢?很简单,在fc1000后面再加一个Dense(128)就行了生成向量之后再求两个向量之间的距离即可判定两个人脸的相似程度.那么如何从0开始构建一个和dlib一样的人脸识别网络呢?就是应该先构建一个resnet34,后面加一个Dense(128),后面再接分类,训练完成后舍弃最后Dense(128)接分类的那一部分,只保留前面的参数,这样每输入一张图片就可以得到一个128维的向量了.

    3.卷积神经网络(CNN):

    第一步:找出所有的面孔,方向梯度直方图(Histogram of Oriented Gradients)”的方法,或简称HOG。

    第二步:脸部的不同姿势,将使用一种称为脸部标志点估计(Face Landmark Estimation)的算法。这一算法的基本思想是,我们找到人脸上普遍存在的68个特定点(称为Landmarks)——下巴的顶部,每只眼睛的外部轮廓,每条眉毛的内部轮廓等。接下来我们训练一个机器学习算法,能够在任何脸部找到这68个特定点。可以自己使用Python和dlib来尝试完成这一步的话,这里有一些代码帮你寻找脸部标志点和图像变形。

    第三步:给脸部编码。这个通过训练卷积神经网络来输出脸部嵌入的过程,需要大量的数据和计算机应用。即使使用昂贵的Nvidia Telsa显卡,它也需要大约24小时的连续训练,才能获得良好的准确性。但一旦网络训练完成,它可以生成任何面孔的测量值,即使它从来没有见过这些面孔!所以这种训练只需一次即可。幸运的是,OpenFace上面的大神已经做完了这些,并且他们发布了几个训练过可以直接使用的网络。

    第4步:从编码中找出人的名字。我们将使用一个简单的线性SVM分类器,但实际上还有很多其他的分类算法可以使用。我们需要做的是训练一个分类器,它可以从一个新的测试图像中获取测量结果,并找出最匹配的是哪个人。分类器运行一次只需要几毫秒,分类器的结果就是人的名字!

    以上内容来源网络。

    2.dlib安装与使用

    2.1conda 换源

    c盘用户目录,.condarc文件:

    channels: - https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/ - defaults show_channel_urls: yes
    2.2更新conda
    conda update -n base -c defaults conda

    2.3创建新环境python3.6,名字叫tensorflow
    conda create -n tensorflow python=3.6
    2.4使用新环境
    conda activate tensorflow

    2.5更新pip
    python -m pip install --upgrade pip
    2.6安装cmake,boost,wheel,dlib==19.6.1
    pip install cmake boost wheel dlib==19.6.1 -i https://pypi.tuna.tsinghua.edu.cn/simple
    2.7安装numpy
    pip install numpy opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple
    2.8把新环境路径加到环境变量
    PYTHON36 D:\Anaconda\envs\tensorflow %PYTHON36%\Scripts; %PYTHON36%\Library\bin; %PYTHON36%;
    2.9打开vscode,首选项设置,找到settings.json

    修改python的路径,重启。

    "python.pythonPath": "D:\\Anaconda\\envs\\tensorflow",
    2.10jupyter使用新环境

    打开prompt:

    conda install nb_conda activate tensorflow pip install ipykernel python -m ipykernel install --user --name tensorflow --display-name tf

    重启jupyter,即可选择。

    3.数据集划分

    2.1笑脸数据集genki4k下载

    链接:https://pan.baidu.com/s/15o_HzQMiOJDVfFVGR3fA9A 提取码:es3u

    2.2下载后解压,分测试集、训练集以及验证集

    2.3数据增强

    需要下载几个包:

    pip install keras pip install tensorflow pip install matplotlib pip3 install pillow

    一定重启一下jupyter。

    import keras import os, shutil train_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\smile\\" train_umsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\unsmile\\" test_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\smile\\" test_umsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\unsmile\\" validation_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\smile\\" validation_unsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\unsmile\\" train_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\" test_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\" validation_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\" from keras import optimizers from keras import layers from keras import models from keras.preprocessing.image import ImageDataGenerator 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')
    2.4查看数据增强过后图片的变化
    import os import matplotlib.pyplot as plt from PIL import Image # This is module with image preprocessing utilities from keras.preprocessing import image fnames = [os.path.join(train_smile_dir, fname) for fname in os.listdir(train_smile_dir)] img_path = fnames[3] img = image.load_img(img_path, target_size=(150, 150)) x = image.img_to_array(img) x = x.reshape((1,) + x.shape) i = 0 for batch in datagen.flow(x, batch_size=1): plt.figure(i) imgplot = plt.imshow(image.array_to_img(batch[0])) i += 1 if i % 4 == 0: break plt.show()

    2.4创建网络

    model = models.Sequential() model.add(layers.Conv2D(32, (3, 3), activation='relu', input_shape=(150, 150, 3))) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(64, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(128, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(128, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Flatten()) model.add(layers.Dropout(0.5)) model.add(layers.Dense(512, activation='relu')) model.add(layers.Dense(1, activation='sigmoid')) model.compile(loss='binary_crossentropy', optimizer=optimizers.RMSprop(lr=1e-4), metrics=['acc'])
    2.5训练模型并保存

    如果需要仅训练指定的批次数,那么可以通过指定steps_per_epoch来实现。指定该参数后,在每个epoch仅仅会训练指定的批次数,然后就会切换到下个epoch。

    如果设置的steps_per_epoch大于每个epoch的最大批次数,数据集不会在每个epoch的最后进行重置,而是尝试获取下一个批次的数据,但是数据集还是会耗尽。

    #归一化处理 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,) # Note that the validation data should not be augmented! test_datagen = ImageDataGenerator(rescale=1./255) train_generator = train_datagen.flow_from_directory( # This is the target directory train_dir, # All images will be resized to 150x150 target_size=(150, 150), batch_size=32, # Since we use binary_crossentropy loss, we need binary labels class_mode='binary') validation_generator = test_datagen.flow_from_directory( validation_dir, target_size=(150, 150), batch_size=32, class_mode='binary') history = model.fit_generator( train_generator, steps_per_epoch=100, epochs=60, validation_data=validation_generator, validation_steps=50)

    查看0或1代表的含义

    train_generator.class_indices
    2.6保存模型
    model.save('data/CNN笑脸识别/smileAndUnsmile.h5')

    画出数据增强过后的训练集与验证集的精确度与损失度的图形

    acc = history.history['acc'] val_acc = history.history['val_acc'] loss = history.history['loss'] val_loss = history.history['val_loss'] epochs = range(len(acc)) plt.plot(epochs, acc, 'bo', label='Training acc') plt.plot(epochs, val_acc, 'b', label='Validation acc') plt.title('Training and validation accuracy') plt.legend() plt.figure() plt.plot(epochs, loss, 'bo', label='Training loss') plt.plot(epochs, val_loss, 'b', label='Validation loss') plt.title('Training and validation loss') plt.legend() plt.show()

    2.7测试图片
    # 单张图片进行判断 是笑脸还是非笑脸 import cv2 from keras.preprocessing import image from keras.models import load_model import numpy as np #加载模型 model = load_model('F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\smileAndUnsmile.h5') #本地图片路径 img_path='F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\unsmile\\file2769.jpg' img = image.load_img(img_path, target_size=(150, 150)) img_tensor = image.img_to_array(img)/255.0 img_tensor = np.expand_dims(img_tensor, axis=0) prediction =model.predict(img_tensor) print(prediction) if prediction[0][0]>0.5: result='非笑脸' else: result='笑脸' print(result)

    结果可能不正确,可能是因为分类的时候有些图片混入其中,由于图片太多我也无法一个个判断,所以会不准确。下次训练可以试试更精确地分类。

    2.8测试视频
    #检测视频或者摄像头中的人脸 import cv2 from keras.preprocessing import image from keras.models import load_model import numpy as np import dlib from PIL import Image model = load_model('data/CNN笑脸识别/smileAndUnsmile_4.h5') detector = dlib.get_frontal_face_detector() video=cv2.VideoCapture(0) font = cv2.FONT_HERSHEY_SIMPLEX def rec(img): gray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) dets=detector(gray,1) if dets is not None: for face in dets: left=face.left() top=face.top() right=face.right() bottom=face.bottom() cv2.rectangle(img,(left,top),(right,bottom),(0,255,0),2) img1=cv2.resize(img[top:bottom,left:right],dsize=(150,150)) img1=cv2.cvtColor(img1,cv2.COLOR_BGR2RGB) img1 = np.array(img1)/255. img_tensor = img1.reshape(-1,150,150,3) prediction =model.predict(img_tensor) if prediction[0][0]>0.5: result='unsmile' else: result='smile' cv2.putText(img, result, (left,top), font, 2, (0, 255, 0), 2, cv2.LINE_AA) cv2.imshow('Video', img) while video.isOpened(): res, img_rd = video.read() if not res: break rec(img_rd) if cv2.waitKey(1) & 0xFF == ord('q'): break video.release() cv2.destroyAllWindows()

    无展示图。

    4.dlib笑脸识别

    4.1直接运行
    import cv2 # 图像处理的库 OpenCv import dlib # 人脸识别的库 dlib import numpy as np # 数据处理的库 numpy class face_emotion(): def __init__(self): self.detector = dlib.get_frontal_face_detector() self.predictor = dlib.shape_predictor("data/data_dlib/shape_predictor_68_face_landmarks.dat") self.cap = cv2.VideoCapture(0) self.cap.set(3, 480) self.cnt = 0 def learning_face(self): line_brow_x = [] line_brow_y = [] while(self.cap.isOpened()): flag, im_rd = self.cap.read() k = cv2.waitKey(1) # 取灰度 img_gray = cv2.cvtColor(im_rd, cv2.COLOR_RGB2GRAY) faces = self.detector(img_gray, 0) font = cv2.FONT_HERSHEY_SIMPLEX # 如果检测到人脸 if(len(faces) != 0): # 对每个人脸都标出68个特征点 for i in range(len(faces)): for k, d in enumerate(faces): cv2.rectangle(im_rd, (d.left(), d.top()), (d.right(), d.bottom()), (0,0,255)) self.face_width = d.right() - d.left() shape = self.predictor(im_rd, d) mouth_width = (shape.part(54).x - shape.part(48).x) / self.face_width mouth_height = (shape.part(66).y - shape.part(62).y) / self.face_width brow_sum = 0 frown_sum = 0 for j in range(17, 21): brow_sum += (shape.part(j).y - d.top()) + (shape.part(j + 5).y - d.top()) frown_sum += shape.part(j + 5).x - shape.part(j).x line_brow_x.append(shape.part(j).x) line_brow_y.append(shape.part(j).y) tempx = np.array(line_brow_x) tempy = np.array(line_brow_y) z1 = np.polyfit(tempx, tempy, 1) self.brow_k = -round(z1[0], 3) brow_height = (brow_sum / 10) / self.face_width # 眉毛高度占比 brow_width = (frown_sum / 5) / self.face_width # 眉毛距离占比 eye_sum = (shape.part(41).y - shape.part(37).y + shape.part(40).y - shape.part(38).y + shape.part(47).y - shape.part(43).y + shape.part(46).y - shape.part(44).y) eye_hight = (eye_sum / 4) / self.face_width if round(mouth_height >= 0.03) and eye_hight<0.56: cv2.putText(im_rd, "smile", (d.left(), d.bottom() + 20), cv2.FONT_HERSHEY_SIMPLEX, 2, (0,255,0), 2, 4) if round(mouth_height<0.03) and self.brow_k>-0.3: cv2.putText(im_rd, "unsmile", (d.left(), d.bottom() + 20), cv2.FONT_HERSHEY_SIMPLEX, 2, (0,255,0), 2, 4) cv2.putText(im_rd, "Face-" + str(len(faces)), (20,50), font, 0.6, (0,0,255), 1, cv2.LINE_AA) else: cv2.putText(im_rd, "No Face", (20,50), font, 0.6, (0,0,255), 1, cv2.LINE_AA) im_rd = cv2.putText(im_rd, "S: screenshot", (20,450), font, 0.6, (255,0,255), 1, cv2.LINE_AA) im_rd = cv2.putText(im_rd, "Q: quit", (20,470), font, 0.6, (255,0,255), 1, cv2.LINE_AA) if (cv2.waitKey(1) & 0xFF) == ord('s'): self.cnt += 1 cv2.imwrite("screenshoot" + str(self.cnt) + ".jpg", im_rd) # 按下 q 键退出 if (cv2.waitKey(1)) == ord('q'): break # 窗口显示 cv2.imshow("Face Recognition", im_rd) self.cap.release() cv2.destroyAllWindows() if __name__ == "__main__": my_face = face_emotion() my_face.learning_face()

    5.口罩识别

    同上,

    5.1数据分类:

    5.2训练:
    import keras import os, shutil train_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\smile\\" train_umsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\unsmile\\" test_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\smile\\" test_umsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\unsmile\\" validation_smile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\smile\\" validation_unsmile_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\unsmile\\" train_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\train\\" test_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\\" validation_dir="F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\validation\\" from keras import optimizers from keras import layers from keras import models from keras.preprocessing.image import ImageDataGenerator 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') import os import matplotlib.pyplot as plt from PIL import Image # This is module with image preprocessing utilities from keras.preprocessing import image fnames = [os.path.join(train_smile_dir, fname) for fname in os.listdir(train_smile_dir)] img_path = fnames[3] img = image.load_img(img_path, target_size=(150, 150)) x = image.img_to_array(img) x = x.reshape((1,) + x.shape) i = 0 for batch in datagen.flow(x, batch_size=1): plt.figure(i) imgplot = plt.imshow(image.array_to_img(batch[0])) i += 1 if i % 4 == 0: break model = models.Sequential() model.add(layers.Conv2D(32, (3, 3), activation='relu', input_shape=(150, 150, 3))) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(64, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(128, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Conv2D(128, (3, 3), activation='relu')) model.add(layers.MaxPooling2D((2, 2))) model.add(layers.Flatten()) model.add(layers.Dropout(0.5)) model.add(layers.Dense(512, activation='relu')) model.add(layers.Dense(1, activation='sigmoid')) model.compile(loss='binary_crossentropy', optimizer=optimizers.RMSprop(lr=1e-4), metrics=['acc']) #归一化处理 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,) # Note that the validation data should not be augmented! test_datagen = ImageDataGenerator(rescale=1./255) train_generator = train_datagen.flow_from_directory( # This is the target directory train_dir, # All images will be resized to 150x150 target_size=(150, 150), batch_size=32, # Since we use binary_crossentropy loss, we need binary labels class_mode='binary') validation_generator = test_datagen.flow_from_directory( validation_dir, target_size=(150, 150), batch_size=32, class_mode='binary') history = model.fit_generator( train_generator, steps_per_epoch=6, epochs=60, validation_data=validation_generator, validation_steps=50) model.save('F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\smileAndUnsmile.h5') acc = history.history['acc'] val_acc = history.history['val_acc'] loss = history.history['loss'] val_loss = history.history['val_loss'] epochs = range(len(acc)) plt.plot(epochs, acc, 'bo', label='Training acc') plt.plot(epochs, val_acc, 'b', label='Validation acc') plt.title('Training and validation accuracy') plt.legend() plt.figure() plt.plot(epochs, loss, 'bo', label='Training loss') plt.plot(epochs, val_loss, 'b', label='Validation loss') plt.title('Training and validation loss') plt.legend() plt.show()

    5.3测试:
    # 单张图片进行判断 是笑脸还是非笑脸 import cv2 from keras.preprocessing import image from keras.models import load_model import numpy as np #加载模型 model = load_model('F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\smileAndUnsmile.h5') #本地图片路径 def pic(img_path): img = image.load_img(img_path, target_size=(150, 150)) img_tensor = image.img_to_array(img)/255.0 img_tensor = np.expand_dims(img_tensor, axis=0) prediction =model.predict(img_tensor) print(prediction) if prediction[0][0]>0.5: result='非笑脸' else: result='笑脸' print(result) a=[] a.append(r'F:\\BaiduNetdiskDownload\\aidazuoye\\smile2\\data\\test\smile\\file1115.jpg') a.append(r"F:\BaiduNetdiskDownload\aidazuoye\smile2\data\test\smile\file1120.jpg") a.append(r'F:\\BaiduNetdiskDownload\\aidazuoye\smile2\\data\\test\unsmile\\file2205.jpg') a.append(r"F:\BaiduNetdiskDownload\aidazuoye\smile2\data\test\unsmile\file2183.jpg") for url in a: pic(url)

    测试完毕。 参考链接:https://blog.csdn.net/miss_bear/article/details/107089854

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