内容简介:了解一下TF的高级API如何使用。看上去好像挺高大上的,其实按照固定的格式使用就可以了。回头再看有点像是的keras的风格了, 呵呵哒。
再议tf.estimator之便利:
了解一下TF的高级API如何使用。
看上去好像挺高大上的,其实按照固定的格式使用就可以了。
回头再看有点像是的keras的风格了, 呵呵哒。
还可以和这篇文章一起看: https://blog.csdn.net/u014365862/article/details/79399775。
# coding = utf-8 ''' 再议tf.estimator之便利。 了解一下TF的高级API如何使用。 看上去好像挺高大上的,其实按照固定的格式使用就可以了。 回头再看有点像是的keras的风格了, 呵呵哒。 还可以和这篇文章一起看: https://blog.csdn.net/u014365862/article/details/79399775。 ''' from __future__ import absolute_import from __future__ import division from __future__ import print_function # Imports import sys import numpy as np import tensorflow as tf import argparse import os.path as osp from PIL import Image from functools import partial import matplotlib matplotlib.use('Agg') import matplotlib.pyplot as plt import sklearn.metrics # 用于模型评估, def compute_map(gt, pred, valid, average=None): """ 计算多标签的准确率。 """ nclasses = gt.shape[1] all_ap = [] for cid in range(nclasses): gt_cls = gt[:, cid][valid[:, cid] > 0].astype('float32') pred_cls = pred[:, cid][valid[:, cid] > 0].astype('float32') # As per PhilK. code: # https://github.com/philkr/voc-classification/blob/master/src/train_cls.py pred_cls -= 1e-5 * gt_cls ap = sklearn.metrics.average_precision_score( gt_cls, pred_cls, average=average) all_ap.append(ap) return all_ap plt.ioff() # 为将要记录的设置开始入口 tf.logging.set_verbosity(tf.logging.INFO) # 定义分类的类别名称 CLASS_NAMES = [ 'aeroplane', 'bicycle', 'bird', 'boat', 'bottle', 'bus', 'car', 'cat', 'chair', 'cow', 'diningtable', 'dog', 'horse', 'motorbike', 'person', 'pottedplant', 'sheep', 'sofa', 'train', 'tvmonitor', ] # 定义模型 # 使用tf.estimator的话,需要按照固定的定义模型的格式。 ''' 参考如下: my_model( features, #输入的特征数据 labels, #输入的标签数据 mode, #train、evaluate或predict params #超参数,对应上面Estimator传来的参数 ) train: 需要以tf.estimator.EstimatorSpec(mode=mode, loss=loss, train_op=train_op)作为return。 其中: mode, #train、evaluate或predict; loss: 损失函数; train_op: 定义优化算法。 predict: 需要以return tf.estimator.EstimatorSpec(mode=mode, predictions=predictions)作为return。 其中: predictions为预测值。 ''' def cnn_model_fn(features, labels, mode, num_classes=20): # Input Layer input_layer = tf.reshape(features["x"], [-1, 256, 256, 3]) valid = features["w"] # Do data augmentation here ! if mode == tf.estimator.ModeKeys.PREDICT: final_input = tf.map_fn(lambda im_tf: tf.image.central_crop(im_tf, float(0.875)), input_layer) if mode == tf.estimator.ModeKeys.TRAIN: final_input = tf.map_fn(lambda im_tf: tf.image.random_flip_left_right(im_tf), input_layer) final_input = tf.map_fn(lambda im_tf: tf.random_crop(im_tf, size=[224,224,3]), final_input) tf.summary.image(name='train_images', tensor=final_input, max_outputs=10) # VGG16 archirecture # Block - 1 conv1 = tf.layers.conv2d(inputs=final_input, filters=64, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv2 = tf.layers.conv2d(inputs=conv1, filters=64, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) pool1 = tf.layers.max_pooling2d(inputs=conv2, pool_size=[2, 2], strides=2) # Block - 2 conv3 = tf.layers.conv2d(inputs=pool1, filters=128, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv4 = tf.layers.conv2d(inputs=conv3, filters=128, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) pool2 = tf.layers.max_pooling2d(inputs=conv4, pool_size=[2, 2], strides=2) # Block - 3 conv5 = tf.layers.conv2d(inputs=pool2, filters=256, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv6 = tf.layers.conv2d(inputs=conv5, filters=256, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv7 = tf.layers.conv2d(inputs=conv6, filters=256, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) pool3 = tf.layers.max_pooling2d(inputs=conv7, pool_size=[2, 2], strides=2) # Block - 4 conv8 = tf.layers.conv2d(inputs=pool3, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv9 = tf.layers.conv2d(inputs=conv8, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv10 = tf.layers.conv2d(inputs=conv9, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) pool4 = tf.layers.max_pooling2d(inputs=conv10, pool_size=[2, 2], strides=2) # Block - 5 conv11 = tf.layers.conv2d(inputs=pool4, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv12 = tf.layers.conv2d(inputs=conv11, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) conv13 = tf.layers.conv2d(inputs=conv12, filters=512, kernel_size=[3,3], padding="same", activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) pool5 = tf.layers.max_pooling2d(inputs=conv13, pool_size=[2, 2], strides=2) pool5_flat = tf.reshape(pool5, [-1, 7*7*512]) # FC Layers dense1 = tf.layers.dense(inputs=pool5_flat, units=4096, activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) dropout1 = tf.layers.dropout(inputs=dense1, rate=0.5, training=mode == tf.estimator.ModeKeys.TRAIN) dense2 = tf.layers.dense(inputs=dropout1, units=4096, activation=tf.nn.relu, use_bias=True, trainable=True, bias_initializer=tf.zeros_initializer(), kernel_initializer=tf.contrib.layers.xavier_initializer()) dropout2 = tf.layers.dropout(inputs=dense2, rate=0.5, training=mode == tf.estimator.ModeKeys.TRAIN) logits = tf.layers.dense(inputs=dropout2, units=num_classes) predictions = {"probabilities": tf.sigmoid(logits, name="sigmoid_tensor")} if mode == tf.estimator.ModeKeys.PREDICT: return tf.estimator.EstimatorSpec(mode=mode, predictions=predictions) loss = tf.identity(tf.losses.sigmoid_cross_entropy(labels, logits=logits), name='loss') # Configure the Training Op (for TRAIN mode) if mode == tf.estimator.ModeKeys.TRAIN: tf.summary.scalar('Train Loss', loss) lr = tf.train.exponential_decay(learning_rate=0.001,global_step=tf.train.get_global_step(),decay_steps=10000,decay_rate=0.5, staircase=True) tf.summary.scalar('Learning rate', lr) optimizer = tf.train.MomentumOptimizer( learning_rate=lr, momentum=0.9) gradients_and_vars = optimizer.compute_gradients(loss, tf.trainable_variables()) for g, v in gradients_and_vars: if g is not None: tf.summary.histogram('gradient histogram'+v.name, g) train_op = optimizer.minimize(loss=loss,global_step=tf.train.get_global_step()) return tf.estimator.EstimatorSpec(mode=mode, loss=loss, train_op=train_op) # 读取数据,将数据都读到内存中 # 并不提倡这种方式,可以选用tf队列的方式,可以参考: https://github.com/MachineLP/train_arch/blob/master/train_cnn_v1/lib/data_load/data_loader.py def load_pascal(data_dir, split='train'): # Get the exact dirs for Images and annorations images_dir = data_dir + '/VOCdevkit/VOC2007/JPEGImages/' annt_dir = data_dir + '/VOCdevkit/VOC2007/ImageSets/Main/' # Get the list of all classes, this is a Global variable global CLASS_NAMES # For the given split, get the dimensionality of output matrices # Do this by opening annotation file for any class, say aeroplane num_images = len(open(annt_dir+CLASS_NAMES[0]+'_'+split+'.txt','r').read().splitlines()) num_classes = len(CLASS_NAMES) # Initialize images, labels, weights matrices images = np.zeros((num_images, 256, 256, 3), dtype='float32') labels = np.zeros((num_images, num_classes), dtype='int') weights = np.zeros((num_images, num_classes), dtype='int') # First load all the images for given split and then check for labels. This is faster. list_all_images = [i.split(' ')[0]+'.jpg' for i in open(annt_dir+CLASS_NAMES[0]+'_'+split+'.txt','r').read().splitlines()] # all files are in jpg format. for given_im in range(0, len(list_all_images)): print('Loading Image: ' + str(given_im)) im_file_path = images_dir + list_all_images[given_im] im = np.asarray(Image.open(im_file_path).resize((256,256)).convert('RGB'), dtype='float32') # Just in case some image in grayscale images[given_im,:,:,:] = im # Now itwrate through annotation files and generate labels and weights for given_cls in range(0, len(CLASS_NAMES)): cls_name = CLASS_NAMES[given_cls] ann_file_name = annt_dir + cls_name + '_' + split + '.txt' cls_data = [i for i in open(ann_file_name, 'r').read().splitlines()] cls_ann = np.zeros((len(cls_data), 1)) for i in range(0, len(cls_data)): list_i = cls_data[i].split(' ') if len(list_i) == 2: cls_ann[i] = int(list_i[1]) elif len(list_i) == 3: cls_ann[i] = int(list_i[2]) for given_im in range(0, len(list_all_images)): if cls_ann[given_im] == 1: labels[given_im][given_cls] = 1 weights[given_im][given_cls] = 1 elif cls_ann[given_im] == 0: labels[given_im][given_cls] = 1 weights[given_im][given_cls] = 0 elif cls_ann[given_im] == -1: labels[given_im][given_cls] = 0 weights[given_im][given_cls] = 1 else: print('Something wrong in annotations: ' + str(given_im) + ' | ' + str(cls_name)) sys.exit(1) return images, labels, weights def parse_args(): parser = argparse.ArgumentParser( description='Train a classifier in tensorflow!') parser.add_argument( 'data_dir', type=str, default='data/VOC2007', help='Path to PASCAL data storage') if len(sys.argv) == 1: parser.print_help() sys.exit(1) args = parser.parse_args() return args def _get_el(arr, i): try: return arr[i] except IndexError: return arr def main(): args = parse_args() BATCH_SIZE = 10 # 定义40行1列的数组,存储计算的mAP。 map_list = np.zeros((40,1), dtype='float') # 加载训练数据 和 测试数据。 train_data, train_labels, train_weights = load_pascal(args.data_dir, split='trainval') eval_data, eval_labels, eval_weights = load_pascal(args.data_dir, split='test') # 定义模型以及参数 pascal_classifier = tf.estimator.Estimator( model_fn=partial(cnn_model_fn, num_classes=train_labels.shape[1]), model_dir="./vgg_models/") # 设置一些日志用于我们跟踪程序运行。我们可以用tf.train.SessionRunHook来创建一个tf.train.LoggingTensorHook,它能够记录我们CNN的loss的值。 tensors_to_log = {"loss": "loss"} logging_hook = tf.train.LoggingTensorHook(tensors=tensors_to_log, at_end=True) # Train the model # 将训练数据拉到tf队列中。 train_input_fn = tf.estimator.inputs.numpy_input_fn( x={"x": train_data, "w": train_weights}, y=train_labels, batch_size=BATCH_SIZE, num_epochs=None, shuffle=True) # Evaluate the model and print results # 将测试数据拉到tf队列中。 eval_input_fn = tf.estimator.inputs.numpy_input_fn( x={"x": eval_data, "w": eval_weights}, y=eval_labels, num_epochs=1, shuffle=False) # 训练迭代一次测试一次 # 这里不要频繁进行测试,会造成io太频繁,GPU利用率很差。 for given_iter in range(0,40): # 模型开始训练, 也是要以固定的格式开始。 pascal_classifier.train(input_fn=train_input_fn, steps=1000, hooks=[logging_hook]) pred = list(pascal_classifier.predict(input_fn=eval_input_fn)) pred = np.stack([p['probabilities'] for p in pred]) AP = compute_map(eval_labels, pred, eval_weights, average=None) print('\nmAP : ' + str(np.mean(AP)) + '\n') map_list[given_iter] = np.mean(AP) xx = range(1,41) plt.plot(xx, map_list, 'r--') plt.xlabel('i*1000 iterations') plt.ylabel('mAP') plt.savefig('pascal_vgg.png') if __name__ == "__main__": main() ''' 还可以参考: https://github.com/MachineLP/Tensorflow-/tree/master/Tensorflow-estimator-classification https://www.jianshu.com/p/5495f87107e7 '''
还可以参考:
https://github.com/MachineLP/Tensorflow-/tree/master/Tensorflow-estimator-classification
https://www.jianshu.com/p/5495f87107e7
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持 码农网
猜你喜欢:- [译] 感受 4px 基线网格带来的便利
- 小卖柜亮相AWE,为便利购物创造更多可能
- #每日一记# 1分钟学会如何「便利地」使用 async/await
- Python的默认参数,为API设计带来了哪些便利
- 张利:见福便利店,蚂蚁雄兵的野蛮生命力
- Java RPC 框架 Solon 1.3.9 发布,更便利的支持
本站部分资源来源于网络,本站转载出于传递更多信息之目的,版权归原作者或者来源机构所有,如转载稿涉及版权问题,请联系我们。