caffe ensemble（模型融合+adaboost）

方法一：模型融合（生成fuse_model和fusion_train_val.prototxt（更改层名/直接将各自的ip1层 concat））   

Caffe中并没有直接用于融合的官方工具，这介绍一个简单有效的土办法，用融合模型进行ensemble

https://github.com/frombeijingwithlove/dlcv_for_beginners/tree/master/random_bonus/multiple_models_fusion_caffe

http://www.cnblogs.com/frombeijingwithlove/p/6683476.html

方法二：adaboost（集成）   （写出ensemble层（前提各模型层名不一样））

参考：http://blog.csdn.net/u014114990/article/details/51005316

ensemble_accuracy_layer.cpp 

Softmax 层和 accuracy 层的配置文件如下：

layer {    name: "3_prob"    type: "Softmax"    bottom: "3_ip2"    top: "3_prob"  }    layer {    name: "1_accuracy"    type: "Accuracy"    bottom: "1_prob"      bottom: "label"    top: "1_accuracy"    include {      phase: TEST    }  } 

ensemble 层配置函数如下：

layer {  name: "ensemble  type: "Esemble"  bottom: "prob1"  bottom: "prob2"   bottom: "prob3"   bottom: "label"  top: "ensemble_accuracy"  include {      phase: TEST  }}

先训练弱分类器，用弱分类器的模型即可，如果把caffe训练好的模型当弱分类器，只需要调用caffe，使用该模型即可，不需要重新训练该弱分类器。

下面代码是调用caffe训练的模型，使用adaboost弱分类器。 这里主要使用了sklearn 库。

#!/usr/bin/env python# -*- coding: utf-8 -*-# author: Tairui Chenimport numpy as npimport osimport sysimport argparseimport globimport timefrom sklearn.base import BaseEstimator, ClassifierMixinfrom sklearn.ensemble import AdaBoostClassifier, BaggingClassifierimport caffeg_rnd = np.random.randint(100000)def create_weighted_db(X, y, weights, name='boost'):    X = X.reshape(-1, 3, 32, 32)    train_fn = os.path.join(DIR, name + '.h5')    dd.io.save(train_fn, dict(data=X,                              label=y.astype(np.float32),                              sample_weight=weights), compress=False)    with open(os.path.join(DIR, name + '.txt'), 'w') as f:        print(train_fn, file=f)class CNN(BaseEstimator, ClassifierMixin):    def __init__(self):        pass    def get_params(self, deep=False):        return {}    def fit(self, X, y, sample_weight=None):        global g_seed        global g_loop        if sample_weight is None:            sample_weight = np.ones(X.shape[0], np.float32)            print('Calling fit with sample_weight None')        else:            sample_weight *= X.shape[0]            print('Calling fit with sample_weight sum', sample_weight.sum())        #sample_weight = np.ones(X.shape[0], np.float32)        #II = sample_weight > 0        #X = X[II]        #y = y[II]        #sample_weight = sample_weight[II]        #sample_weight = np.ones(X.shape[0])        w = sample_weight        #sample_weight[:10] = 0.0        #w[:1000] = 0.0        #w = sample_weight        #w0 = w / w.sum()        #print('Weight entropy:', -np.sum(w0 * np.log2(w0)))        print('Weight max:', w.max())        print('Weight min:', w.min())        #import sys; sys.exit(0)        self.classes_ = np.unique(y)        self.n_classes_ = len(self.classes_)        # Set up weighted database        create_weighted_db(X, y, sample_weight)        #steps = [(0.001, 2000, 2000)]        steps = [(0.001, 0.004, 60000), (0.0001, 0.004, 5000), (0.00001, 0.004, 5000)]        #steps = [(0.00001, 10000, 10000), (0.000001, 5000, 15000), (0.0000001, 5000, 20000)]        #steps = [(0.001, 10000, 10000)]        #steps = [(0.001, 200, 1000)]        name = os.path.join(CONF_DIR, 'adaboost_{}_loop{}'.format(g_rnd, g_loop))        bare_conf_fn = os.path.join(CONF_DIR, 'boost_bare.prototxt')        conf_fn = os.path.join(CONF_DIR, 'solver.prototxt.template')        #bare_conf_fn = 'regaug_bare.prototxt'        #conf_fn = 'regaug_solver.prototxt.template'        net, info = train_model(name, conf_fn, bare_conf_fn, steps,                                seed=g_seed, device_id=DEVICE_ID)        loss_fn = 'info/info_{}_loop{}.h5'.format(g_rnd, g_loop)        dd.io.save(loss_fn, info)        print('Saved to', loss_fn)        g_loop += 1        print('Classifier set up')        self.net_ = net    def predict_proba(self, X):        X = X.reshape(-1, 3, 32, 32)        #X = X.transpose(0, 2, 3, 1)        prob = np.zeros((X.shape[0], self.n_classes_))        M = 2500        for k in range(int(np.ceil(X.shape[0] / M))):            y = self.net_.forward_all(data=X[k*M:(k+1)*M]).values()[0].squeeze(axis=(2,3))            prob[k*M:(k+1)*M] = y        T = 30.0        eps = 0.0001        #prob = prob.clip(eps, 1-eps)        log_prob = np.log(prob)        print('log_prob', log_prob.min(), log_prob.max())        #log_prob = log_prob.clip(min=-4, max=4)        new_prob = np.exp(log_prob / T)        new_prob /= dd.apply_once(np.sum, new_prob, [1])        return new_prob    def predict(self, X):        prob = self.predict_proba(X)        return prob.argmax(-1)train_data = np.load('G:/EDU/_SOURCE_CODE/chainer/examples/cifar10/data/train_data.npy')train_labels = np.load('G:/EDU/_SOURCE_CODE/chainer/examples/cifar10/data/train_labels.npy')model_path = 'cifar10/' # substitute your path here# GoogleNetnet_fn   = model_path + 'VGG_mini_ABN.prototxt'param_fn = model_path + 'cifar10_vgg_iter_120000.caffemodel'caffe.set_mode_cpu()net = caffe.Classifier(net_fn, param_fn,                       mean = np.float32([104.0, 116.0, 122.0]), # ImageNet mean, training set dependent                       channel_swap = (2,1,0)) # the reference model has channels in BGR order instead of RGBdef preprocess(net, img):    return np.float32(np.rollaxis(img, 2)[::-1]) - net.transformer.mean['data']for i in range(10):img = train_data[i].transpose((1, 2, 0)) * 255img = img.astype(np.uint8)[:, :, ::-1]end = 'prob'h, w = img.shape[:2]src, dst = net.blobs['data'], net.blobs[end]src.data[0] = preprocess(net, img)net.forward(end=end)features = dst.data[0].copy()  X = train_datay = train_labelsX *= 255.0mean_x = X.mean(0)X -= mean_xte_X= np.load('G:/EDU/_SOURCE_CODE/chainer/examples/cifar10/data/test_data.npy')te_y = np.load('G:/EDU/_SOURCE_CODE/chainer/examples/cifar10/data/test_labels.npy')create_weighted_db(te_X, te_y, np.ones(te_X.shape[0], dtype=np.float32), name='test')  clf = AdaBoostClassifier(base_estimator=CNN(), algorithm='SAMME.R', n_estimators=10,                                 random_state=0)clf.fit(X.reshape(X.shape[0], -1), y)for i, score in enumerate(clf.staged_score(X.reshape(X.shape[0], -1), y)):                print(i+1, 'train score', score)for i, score in enumerate(clf.staged_score(te_X.reshape(te_X.shape[0], -1), te_y)):                print(i+1, 'test score', score)