Exemplo n.º 1
0
def plot_curve():
    io.log('Loading cross-validation values...')
    cv_values = io.load_object('intersection_svm_CNNfeatures', ignore=True)

    io.log('Loading best parameters...')
    best_params = io.load_object('best_params_intersection_svm_CNNfeatures1',
                                 ignore=True)

    io.log('Plotting...')
    colors = itertools.cycle([
        'blue', 'green', 'red', 'cyan', 'magenta', 'yellow', 'darkolivegreen',
        'darkviolet', 'black'
    ])

    # Subplot parameters
    plt.figure(facecolor='white')
    num_subplots = len(codebook_size)
    num_columns = 1
    num_rows = np.ceil(num_subplots / num_columns)

    # All subplots
    for ind, k in enumerate(codebook_size):
        # Search dictionary
        val = cv_values[(k)]
        results = val['cv_results']
        feature_time = val['feature_time']
        pca_time = val['pca_time']
        gmm_time = val['gmm_time']
        fisher_time = val['fisher_time']
        scaler_time = val['scaler_time']
        crossvalidation_time = val['crossvalidation_time']
        total_time = val['total_time']

        # Plot
        x = results['param_C']
        y = results['mean_test_score']
        e = results['std_test_score']
        sorted_indices = x.argsort()
        x_sorted = np.asarray(x[sorted_indices], dtype=np.float64)
        y_sorted = np.asarray(y[sorted_indices], dtype=np.float64)
        e_sorted = np.asarray(e[sorted_indices], dtype=np.float64)
        color = colors.next()
        ax = plt.subplot(num_rows, num_columns, ind + 1)
        ax.set_xscale("log")
        ax.set_ylim((0.7, 0.9))
        ax.errorbar(x_sorted,
                    y_sorted,
                    e_sorted,
                    linestyle='--',
                    lw=2,
                    marker='x',
                    color=color)
        ax.set_title('{} Gaussians in GMM'.format(k))
        ax.set_xlabel('C')
        ax.set_ylabel('Accuracy')

        # Print information
        io.log('CODEBOOK {} '.format(k))
        io.log('-------------')
        io.log('Mean accuracy: {}'.format(y.max()))
        io.log('Std accuracy: {}'.format(e[np.argmax(y)]))
        io.log('C: {}'.format(x[np.argmax(y)]))
        io.log()
        io.log('Timing')
        io.log('\tSIFT time: {:.2f} s'.format(feature_time))
        io.log('\tPCA time: {:.2f} s'.format(pca_time))
        io.log('\tGMM time: {:.2f} s'.format(gmm_time))
        io.log('\tFisher time: {:.2f} s'.format(fisher_time))
        io.log('\tScaler time: {:.2f} s'.format(scaler_time))
        io.log('\tCV time: {:.2f} s'.format(crossvalidation_time))
        io.log('\t_________________________')
        io.log('\tTOTAL TIME: {:.2f} s'.format(total_time))
        io.log()
    plt.tight_layout()
    plt.show()
    plt.close()
Exemplo n.º 2
0
def train():
    best_accuracy = 0
    best_params = {}
    cv_results = {}

    base_model = VGG16(weights='imagenet')

    # crop the model up to a certain layer
    model = Model(input=base_model.input,
                  output=base_model.get_layer('block5_conv2').output)

    # Read the training set
    train_images_filenames = cPickle.load(
        open('./dataset/train_images_filenames.dat', 'r'))
    test_images_filenames = cPickle.load(
        open('./dataset/test_images_filenames.dat', 'r'))
    train_labels = cPickle.load(open('./dataset/train_labels.dat', 'r'))
    test_labels = cPickle.load(open('./dataset/test_labels.dat', 'r'))
    io.log('\nLoaded {} train images.'.format(len(train_images_filenames)))
    io.log('\nLoaded {} test images.'.format(len(test_images_filenames)))

    # read and process training images
    print 'Getting features from training images'
    start_feature = time.time()
    Train_descriptors = []
    Train_label_per_descriptor = []

    for i in range(len(train_images_filenames)):
        img = image.load_img(train_images_filenames[i], target_size=(224, 224))
        x = image.img_to_array(img)
        x = np.expand_dims(x, axis=0)
        x = preprocess_input(x)

        # get the features from images
        features = model.predict(x)
        features = features[0, :, :, :]
        descriptor = features.reshape(features.shape[0] * features.shape[1],
                                      features.shape[2])

        Train_descriptors.append(descriptor)
        Train_label_per_descriptor.append(train_labels[i])

    # Put all descriptors in a numpy array to compute PCA and GMM
    size_descriptors = Train_descriptors[0].shape[1]
    Desc = np.zeros(
        (np.sum([len(p) for p in Train_descriptors]), size_descriptors),
        dtype=np.uint8)
    startingpoint = 0
    for i in range(len(Train_descriptors)):
        Desc[startingpoint:startingpoint +
             len(Train_descriptors[i])] = Train_descriptors[i]
        startingpoint += len(Train_descriptors[i])
    feature_time = time.time() - start_feature
    io.log('Elapsed time: {:.2f} s'.format(feature_time))

    for dim_red in pca_reduction:
        io.log('Applying PCA ... ')
        start_pca = time.time()
        reduction = np.int(dim_red * Desc.shape[1])
        pca = decomposition.PCA(n_components=reduction)
        pca.fit(Desc)
        Desc_pca = np.float32(pca.transform(Desc))
        pca_time = time.time() - start_pca
        io.log('Elapsed time: {:.2f} s'.format(pca_time))
        for k in codebook_size:
            io.log('Creating GMM model (k = {})'.format(k))
            start_gmm = time.time()
            gmm = ynumpy.gmm_learn(np.float32(Desc_pca), k)
            io.save_object(gmm, 'gmm_NN_pca_{}_k_{}'.format(reduction, k))
            gmm_time = time.time() - start_gmm
            io.log('Elapsed time: {:.2f} s'.format(gmm_time))

            io.log('Getting Fisher vectors from training set...')
            start_fisher = time.time()
            fisher = np.zeros((len(Train_descriptors), k * reduction * 2),
                              dtype=np.float32)
            for i in xrange(len(Train_descriptors)):
                descriptor = Train_descriptors[i]
                descriptor = np.float32(pca.transform(descriptor))
                fisher[i, :] = ynumpy.fisher(gmm,
                                             descriptor,
                                             include=['mu', 'sigma'])
                # L2 normalization - reshape to avoid deprecation warning, checked that the result is the same
                fisher[i, :] = preprocessing.normalize(fisher[i, :].reshape(
                    1, -1),
                                                       norm='l2')

            fisher_time = time.time() - start_fisher
            io.log('Elapsed time: {:.2f} s'.format(fisher_time))

            io.log('Scaling features...')
            start_scaler = time.time()
            stdSlr = StandardScaler().fit(fisher)
            D_scaled = stdSlr.transform(fisher)
            scaler_time = time.time() - start_scaler
            io.log('Elapsed time: {:.2f} s'.format(scaler_time))

            io.log('Optimizing SVM hyperparameters...')
            start_crossvalidation = time.time()
            svm = SVC(kernel='precomputed')
            random_search = RandomizedSearchCV(svm,
                                               params_distribution,
                                               n_iter=n_iter,
                                               scoring='accuracy',
                                               refit=False,
                                               cv=3,
                                               verbose=1)
            # Precompute Gram matrix
            gram = kernels.intersection_kernel(D_scaled, D_scaled)
            random_search.fit(gram, train_labels)
            crossvalidation_time = time.time() - start_crossvalidation
            io.log('Elapsed time: {:.2f} s'.format(crossvalidation_time))

            # Convert MaskedArrays to ndarrays to avoid unpickling bugs
            results = random_search.cv_results_
            results['param_C'] = results['param_C'].data

            # Appending all parameter-scores combinations
            cv_results.update({
                (k): {
                    'cv_results':
                    results,
                    'feature_time':
                    feature_time,
                    'pca_time':
                    pca_time,
                    'gmm_time':
                    gmm_time,
                    'fisher_time':
                    fisher_time,
                    'scaler_time':
                    scaler_time,
                    'crossvalidation_time':
                    crossvalidation_time,
                    'total_time':
                    feature_time + pca_time + gmm_time + fisher_time +
                    scaler_time + crossvalidation_time
                }
            })
            io.save_object(cv_results,
                           'intersection_svm_CNNfeatures',
                           ignore=True)

            # Obtaining the parameters which yielded the best accuracy
            if random_search.best_score_ > best_accuracy:
                best_accuracy = random_search.best_score_
                best_params = random_search.best_params_
                best_params.update({'k': k, 'pca': dim_red})

            io.log('-------------------------------\n')
    io.log('\nSaving best parameters...')
    io.save_object(best_params,
                   'best_params_intersection_svm_CNNfeatures',
                   ignore=True)
    best_params_file = os.path.abspath(
        './ignore/best_params_intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(best_params_file))

    io.log('\nSaving all cross-validation values...')
    io.save_object(cv_results, 'intersection_svm_CNNfeatures', ignore=True)
    cv_results_file = os.path.abspath(
        './ignore/intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(cv_results_file))

    io.log('\nBEST PARAMS')
    io.log('k={}, dim_red={}, C={} --> accuracy: {:.3f}'.format(
        best_params['k'], best_params['pca'], best_params['C'], best_accuracy))
Exemplo n.º 3
0
def train():
    best_accuracy = 0
    best_params = {}
    cv_results = {}

    base_model = VGG16(weights='imagenet')

    # crop the model up to a certain layer
    model = Model(input=base_model.input,
                  output=base_model.get_layer('fc2').output)

    # Read the training set
    train_images_filenames = cPickle.load(
        open('./dataset/train_images_filenames.dat', 'r'))
    test_images_filenames = cPickle.load(
        open('./dataset/test_images_filenames.dat', 'r'))
    train_labels = cPickle.load(open('./dataset/train_labels.dat', 'r'))
    test_labels = cPickle.load(open('./dataset/test_labels.dat', 'r'))
    io.log('\nLoaded {} train images.'.format(len(train_images_filenames)))
    io.log('\nLoaded {} test images.'.format(len(test_images_filenames)))

    # read and process training images
    print 'Getting features from training images'
    start_feature = time.time()

    first = 1
    for i in range(len(train_images_filenames)):
        img = image.load_img(train_images_filenames[i], target_size=(224, 224))
        x = image.img_to_array(img)
        x = np.expand_dims(x, axis=0)
        x = preprocess_input(x)

        # get the features from images
        features = model.predict(x)
        features = features[0, :]
        if first == 1:
            Desc = features
            first = 0
        else:
            Desc = np.vstack((Desc, features))

    feature_time = time.time() - start_feature
    io.log('Elapsed time: {:.2f} s'.format(feature_time))

    io.log('Scaling features...')
    start_scaler = time.time()
    stdSlr = StandardScaler().fit(Desc)
    D_scaled = stdSlr.transform(Desc)
    scaler_time = time.time() - start_scaler
    io.log('Elapsed time: {:.2f} s'.format(scaler_time))

    io.log('Optimizing SVM hyperparameters...')
    start_crossvalidation = time.time()
    svm = SVC(kernel='precomputed', probability=True)
    random_search = RandomizedSearchCV(svm,
                                       params_distribution,
                                       n_iter=n_iter,
                                       scoring='accuracy',
                                       refit=False,
                                       cv=3,
                                       verbose=1)

    # Precompute Gram matrix
    gram = kernels.intersection_kernel(D_scaled, D_scaled)
    random_search.fit(gram, train_labels)
    crossvalidation_time = time.time() - start_crossvalidation
    io.log('Elapsed time: {:.2f} s'.format(crossvalidation_time))

    # Convert MaskedArrays to ndarrays to avoid unpickling bugs
    results = random_search.cv_results_
    results['param_C'] = results['param_C'].data

    # Appending all parameter-scores combinations
    cv_results.update({
        'cv_results':
        results,
        'feature_time':
        feature_time,
        'scaler_time':
        scaler_time,
        'crossvalidation_time':
        crossvalidation_time,
        'total_time':
        feature_time + scaler_time + crossvalidation_time
    })
    io.save_object(cv_results, 'intersection_svm_CNNfeatures', ignore=True)
    print('Best accuracy ' + str(random_search.best_score_))
    # Obtaining the parameters which yielded the best accuracy
    if random_search.best_score_ > best_accuracy:
        best_accuracy = random_search.best_score_
        best_params = random_search.best_params_

    io.log('-------------------------------\n')
    io.log('\nSaving best parameters...')
    io.save_object(best_params,
                   'best_params_intersection_svm_CNNfeatures',
                   ignore=True)
    best_params_file = os.path.abspath(
        './ignore/best_params_intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(best_params_file))

    io.log('\nSaving all cross-validation values...')
    io.save_object(cv_results, 'intersection_svm_CNNfeatures', ignore=True)
    cv_results_file = os.path.abspath(
        './ignore/intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(cv_results_file))

    io.log('\nBEST PARAMS')
    io.log('C={} --> accuracy: {:.3f}'.format(best_params['C'], best_accuracy))
def train():
    best_accuracy = 0
    best_params = {}
    cv_results = {}
    """ SETTINGS """
    settings.n_jobs = 1

    # Read the training set
    train_images_filenames, train_labels = io.load_training_set()
    io.log('Loaded {} train images.'.format(len(train_images_filenames)))
    k = 64

    io.log('Obtaining dense CNN features...')
    start_feature = time.time()
    try:
        D, L, I = io.load_object('train_CNN_descriptors', ignore=True), \
                  io.load_object('train_CNN_labels', ignore=True), \
                  io.load_object('train_CNN_indices', ignore=True)
    except IOError:
        # load VGG model
        base_model = VGG16(weights='imagenet')
        # io.save_object(base_model, 'base_model', ignore=True)

        # visualize topology in an image
        plot(base_model,
             to_file='modelVGG16.png',
             show_shapes=True,
             show_layer_names=True)

        # crop the model up to a certain layer
        model = Model(input=base_model.input,
                      output=base_model.get_layer('block5_conv2').output)
        D, L, I = feature_extraction.parallel_CNN_features(
            train_images_filenames,
            train_labels,
            model,
            num_samples_class=-1,
            n_jobs=settings.n_jobs)
        io.save_object(D, 'train_CNN_descriptors', ignore=True)
        io.save_object(L, 'train_CNN_labels', ignore=True)
        io.save_object(I, 'train_CNN_indices', ignore=True)
    feature_time = time.time() - start_feature
    io.log('Elapsed time: {:.2f} s'.format(feature_time))

    for dim_red in pca_reduction:
        io.log('Applying PCA ... ')
        start_pca = time.time()
        settings.pca_reduction = D.shape[1] * dim_red
        pca, D_pca = feature_extraction.pca(D)
        pca_time = time.time() - start_pca
        io.log('Elapsed time: {:.2f} s'.format(pca_time))
        for k in codebook_size:
            io.log('Creating GMM model (k = {})'.format(k))
            start_gmm = time.time()
            settings.codebook_size = k
            gmm = bovw.create_gmm(
                D_pca,
                'gmm_{}_pca_{}_CNNfeature'.format(k, settings.pca_reduction))
            gmm_time = time.time() - start_gmm
            io.log('Elapsed time: {:.2f} s'.format(gmm_time))

            io.log('Getting Fisher vectors from training set...')
            start_fisher = time.time()
            fisher, labels = bovw.fisher_vectors(D_pca,
                                                 L,
                                                 I,
                                                 gmm,
                                                 normalization='l2')
            fisher_time = time.time() - start_fisher
            io.log('Elapsed time: {:.2f} s'.format(fisher_time))

            io.log('Scaling features...')
            start_scaler = time.time()
            std_scaler = StandardScaler().fit(fisher)
            vis_words = std_scaler.transform(fisher)
            scaler_time = time.time() - start_scaler
            io.log('Elapsed time: {:.2f} s'.format(scaler_time))

            io.log('Optimizing SVM hyperparameters...')
            start_crossvalidation = time.time()
            svm = SVC(kernel='precomputed')
            random_search = RandomizedSearchCV(svm,
                                               params_distribution,
                                               n_iter=n_iter,
                                               scoring='accuracy',
                                               n_jobs=settings.n_jobs,
                                               refit=False,
                                               cv=3,
                                               verbose=1)
            # Precompute Gram matrix
            gram = kernels.intersection_kernel(vis_words, vis_words)
            random_search.fit(gram, labels)
            crossvalidation_time = time.time() - start_crossvalidation
            io.log('Elapsed time: {:.2f} s'.format(crossvalidation_time))

            # Convert MaskedArrays to ndarrays to avoid unpickling bugs
            results = random_search.cv_results_
            results['param_C'] = results['param_C'].data

            # Appending all parameter-scores combinations
            cv_results.update({
                (k): {
                    'cv_results':
                    results,
                    'feature_time':
                    feature_time,
                    'pca_time':
                    pca_time,
                    'gmm_time':
                    gmm_time,
                    'fisher_time':
                    fisher_time,
                    'scaler_time':
                    scaler_time,
                    'crossvalidation_time':
                    crossvalidation_time,
                    'total_time':
                    feature_time + pca_time + gmm_time + fisher_time +
                    scaler_time + crossvalidation_time
                }
            })
            io.save_object(cv_results,
                           'intersection_svm_CNNfeatures',
                           ignore=True)

            # Obtaining the parameters which yielded the best accuracy
            if random_search.best_score_ > best_accuracy:
                best_accuracy = random_search.best_score_
                best_params = random_search.best_params_
                best_params.update({'k': k, 'pca': dim_red})

            io.log('-------------------------------\n')
    io.log('\nSaving best parameters...')
    io.save_object(best_params,
                   'best_params_intersection_svm_CNNfeatures',
                   ignore=True)
    best_params_file = os.path.abspath(
        './ignore/best_params_intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(best_params_file))

    io.log('\nSaving all cross-validation values...')
    io.save_object(cv_results, 'intersection_svm_CNNfeatures', ignore=True)
    cv_results_file = os.path.abspath(
        './ignore/intersection_svm_CNNfeatures.pickle')
    io.log('Saved at {}'.format(cv_results_file))

    io.log('\nBEST PARAMS')
    io.log('k={}, dim_red={}, C={} --> accuracy: {:.3f}'.format(
        best_params['k'], best_params['pca'], best_params['C'], best_accuracy))
Exemplo n.º 5
0
    C=0.0428307453111
    pca_reduction = 52


    # load VGG model
    base_model = VGG16(weights='imagenet')

    # crop the model up to a certain layer
    model = Model(input=base_model.input, output=base_model.get_layer('block5_conv2').output)

    # get train and test images
    train_images_filenames = cPickle.load(open('./dataset/train_images_filenames.dat', 'r'))
    test_images_filenames = cPickle.load(open('./dataset/test_images_filenames.dat', 'r'))
    train_labels = cPickle.load(open('./dataset/train_labels.dat', 'r'))
    test_labels = cPickle.load(open('./dataset/test_labels.dat', 'r'))
    io.log('\nLoaded {} train images.'.format(len(train_images_filenames)))
    io.log('\nLoaded {} test images.'.format(len(test_images_filenames)))


    # read and process training images
    print 'Getting features from training images'
    Train_descriptors = []
    Train_label_per_descriptor = []

    for i in range(len(train_images_filenames)):

        img = image.load_img(train_images_filenames[i], target_size=(224, 224))
        x = image.img_to_array(img)
        x = np.expand_dims(x, axis=0)
        x = preprocess_input(x)
Exemplo n.º 6
0
def train():
    best_accuracy = 0
    best_params = {}
    cv_results = {}
    """ SETTINGS """
    settings.n_jobs = 1

    # Read the training set
    train_images_filenames, train_labels = io.load_training_set()
    io.log('Loaded {} train images.'.format(len(train_images_filenames)))

    # Parameter sweep for dense SIFT
    for ds in dense_sampling_density:

        io.log('Obtaining dense features with sampling parameter {}...'.format(
            ds))
        start_sift = time.time()
        settings.dense_sampling_density = ds
        try:
            D, L, I = io.load_object('train_dense_descriptors_{}'.format(settings.dense_sampling_density), ignore=True), \
                      io.load_object('train_dense_labels_{}'.format(settings.dense_sampling_density), ignore=True), \
                      io.load_object('train_dense_indices_{}'.format(settings.dense_sampling_density), ignore=True)
        except IOError:
            D, L, I, _ = feature_extraction.parallel_dense(
                train_images_filenames,
                train_labels,
                num_samples_class=-1,
                n_jobs=settings.n_jobs)
            io.save_object(D,
                           'train_dense_descriptors_{}'.format(
                               settings.dense_sampling_density),
                           ignore=True)
            io.save_object(L,
                           'train_dense_labels_{}'.format(
                               settings.dense_sampling_density),
                           ignore=True)
            io.save_object(I,
                           'train_dense_indices_{}'.format(
                               settings.dense_sampling_density),
                           ignore=True)
        sift_time = time.time() - start_sift
        io.log('Elapsed time: {:.2f} s'.format(sift_time))

        # Parameter sweep for PCA
        for dim_red in pca_reduction:

            io.log('Applying PCA (dim = {})...'.format(dim_red))
            start_pca = time.time()
            settings.pca_reduction = dim_red
            pca, D_pca = feature_extraction.pca(D)
            pca_time = time.time() - start_pca
            io.log('Elapsed time: {:.2f} s'.format(pca_time))

            # Parameter sweep for codebook size
            for k in codebook_size:

                io.log('Creating GMM model (k = {})'.format(k))
                start_gmm = time.time()
                settings.codebook_size = k
                gmm = bovw.create_gmm(
                    D_pca, 'gmm_{}_dense_{}_pca_{}'.format(k, ds, dim_red))
                gmm_time = time.time() - start_gmm
                io.log('Elapsed time: {:.2f} s'.format(gmm_time))

                io.log('Getting Fisher vectors from training set...')
                start_fisher = time.time()
                fisher, labels = bovw.fisher_vectors(D_pca,
                                                     L,
                                                     I,
                                                     gmm,
                                                     normalization='l2')
                fisher_time = time.time() - start_fisher
                io.log('Elapsed time: {:.2f} s'.format(fisher_time))

                io.log('Scaling features...')
                start_scaler = time.time()
                std_scaler = StandardScaler().fit(fisher)
                vis_words = std_scaler.transform(fisher)
                scaler_time = time.time() - start_scaler
                io.log('Elapsed time: {:.2f} s'.format(scaler_time))

                io.log('Optimizing SVM hyperparameters...')
                start_crossvalidation = time.time()
                svm = SVC(kernel='precomputed')
                random_search = RandomizedSearchCV(svm,
                                                   params_distribution,
                                                   n_iter=n_iter,
                                                   scoring='accuracy',
                                                   n_jobs=settings.n_jobs,
                                                   refit=False,
                                                   cv=3,
                                                   verbose=1)
                # Precompute Gram matrix
                gram = kernels.intersection_kernel(vis_words, vis_words)
                random_search.fit(gram, labels)
                crossvalidation_time = time.time() - start_crossvalidation
                io.log('Elapsed time: {:.2f} s'.format(crossvalidation_time))

                # Convert MaskedArrays to ndarrays to avoid unpickling bugs
                results = random_search.cv_results_
                results['param_C'] = results['param_C'].data

                # Appending all parameter-scores combinations
                cv_results.update({
                    (k, dim_red, ds): {
                        'cv_results':
                        results,
                        'sift_time':
                        sift_time,
                        'pca_time':
                        pca_time,
                        'gmm_time':
                        gmm_time,
                        'fisher_time':
                        fisher_time,
                        'scaler_time':
                        scaler_time,
                        'crossvalidation_time':
                        crossvalidation_time,
                        'total_time':
                        sift_time + pca_time + gmm_time + fisher_time +
                        scaler_time + crossvalidation_time
                    }
                })
                io.save_object(
                    cv_results,
                    'intersection_svm_optimization_fisher_vectors_l2',
                    ignore=True)

                # Obtaining the parameters which yielded the best accuracy
                if random_search.best_score_ > best_accuracy:
                    best_accuracy = random_search.best_score_
                    best_params = random_search.best_params_
                    best_params.update({'k': k, 'pca': dim_red, 'ds': ds})

                io.log('-------------------------------\n')

    io.log('\nSaving best parameters...')
    io.save_object(
        best_params,
        'best_params_intersection_svm_optimization_fisher_vectors_l2',
        ignore=True)
    best_params_file = os.path.abspath(
        './ignore/best_params_intersection_svm_optimization_fisher_vectors_l2.pickle'
    )
    io.log('Saved at {}'.format(best_params_file))

    io.log('\nSaving all cross-validation values...')
    io.save_object(cv_results,
                   'intersection_svm_optimization_fisher_vectors_l2',
                   ignore=True)
    cv_results_file = os.path.abspath(
        './ignore/intersection_svm_optimization_fisher_vectors_l2.pickle')
    io.log('Saved at {}'.format(cv_results_file))

    io.log('\nBEST PARAMS')
    io.log('k={}, C={}, dim_red={}, dense_grid={} --> accuracy: {:.3f}'.format(
        best_params['k'], best_params['C'], best_params['pca'],
        best_params['ds'], best_accuracy))
Exemplo n.º 7
0
def train():
    best_accuracy = 0
    best_params = {}
    cv_results = {}

    # load VGG model
    base_model = VGG16(weights='imagenet')

    # crop the model up to a certain layer
    model = Model(input=base_model.input,
                  output=base_model.get_layer('block5_conv2').output)

    # aggregating features with max-pooling
    # inputs = Input(shape=[14, 14, 512])
    # x = MaxPooling2D((2, 2), strides=(2, 2), name='max_pooling_layer')(inputs)
    # model_agg = Model(inputs, x, name='agg_features')

    # get train and test images
    train_images_filenames = cPickle.load(
        open('./dataset/train_images_filenames.dat', 'r'))
    train_labels = cPickle.load(open('./dataset/train_labels.dat', 'r'))
    io.log('\nLoaded {} train images.'.format(len(train_images_filenames)))

    # read and process training images
    print 'Getting features from training images'
    Train_descriptors = []
    Train_label_per_descriptor = []

    for i in range(len(train_images_filenames)):

        img = image.load_img(train_images_filenames[i], target_size=(224, 224))
        x = image.img_to_array(img)
        x = np.expand_dims(x, axis=0)
        x = preprocess_input(x)

        # get the features from images
        features_ = model.predict(x)
        features = features_[0, :, :, :]
        descriptor = features.reshape(features.shape[0] * features.shape[1],
                                      features.shape[2])
        # aggregate features
        # max value (can be different filters)
        #descriptor_agg=descriptor.max(axis=1)
        # sum value (of all layers)
        #descriptor_agg=np.sum(descriptor,axis=1)
        # max value of just one filter
        energy = descriptor.max(axis=0)
        descriptor_agg = descriptor[:, np.argmax(energy)]

        descriptor_agg = np.reshape(descriptor_agg,
                                    [descriptor_agg.shape[0], 1])

        Train_descriptors.append(descriptor_agg)
        Train_label_per_descriptor.append(train_labels[i])

    # Put all descriptors in a numpy array to compute PCA and GMM
    size_descriptors = Train_descriptors[0].shape[1]
    #size_descriptors=1
    Desc = np.zeros(
        (np.sum([len(p) for p in Train_descriptors]), size_descriptors),
        dtype=np.uint8)
    startingpoint = 0
    for i in range(len(Train_descriptors)):
        Desc[startingpoint:startingpoint +
             len(Train_descriptors[i])] = Train_descriptors[i]
        startingpoint += len(Train_descriptors[i])

    for k in codebook_size:

        print('Computing gmm with ' + str(k) + ' centroids')
        gmm = ynumpy.gmm_learn(np.float32(Desc), k)
        # io.save_object(gmm, 'gmm_NN_agg_features_max')

        # Compute the fisher vectors of the training images
        print('Computing fisher vectors')
        fisher = np.zeros((len(Train_descriptors), k * 1 * 2),
                          dtype=np.float32)

        for i in xrange(len(Train_descriptors)):
            descriptor = Train_descriptors[i]
            # descriptor = np.float32(pca.transform(descriptor))
            aux = ynumpy.fisher(gmm, descriptor, include=['mu', 'sigma'])
            fisher[i, :] = np.reshape(aux, [1, aux.shape[0]])
            #fisher[i,:]=aux
            # L2 normalization - reshape to avoid deprecation warning, checked that the result is the same
            fisher[i, :] = preprocessing.normalize(fisher[i, :].reshape(1, -1),
                                                   norm='l2')

    # CV in SVM training
        io.log('Scaling features...')
        std_scaler = StandardScaler().fit(fisher)
        vis_words = std_scaler.transform(fisher)

        io.log('Optimizing SVM hyperparameters...')
        svm = SVC(kernel='precomputed')
        random_search = RandomizedSearchCV(svm,
                                           params_distribution,
                                           n_iter=n_iter,
                                           scoring='accuracy',
                                           n_jobs=1,
                                           refit=False,
                                           cv=3,
                                           verbose=1)
        # Precompute Gram matrix
        gram = kernels.intersection_kernel(vis_words, vis_words)
        random_search.fit(gram, train_labels)

        # Convert MaskedArrays to ndarrays to avoid unpickling bugs
        results = random_search.cv_results_
        results['param_C'] = results['param_C'].data

        # Appending all parameter-scores combinations
        cv_results.update({(k): {
                               'cv_results': results,
                           }})
        io.save_object(cv_results,
                       'intersection_svm_CNNfeatures_aggregate_energy',
                       ignore=True)

        # Obtaining the parameters which yielded the best accuracy
        if random_search.best_score_ > best_accuracy:
            best_accuracy = random_search.best_score_
            best_params = random_search.best_params_
            best_params.update({'k': k})

        io.log('-------------------------------\n')
    io.log('\nSaving best parameters...')
    io.save_object(best_params,
                   'best_params_intersection_svm_CNNfeatures_aggregate_energy',
                   ignore=True)
    best_params_file = os.path.abspath(
        './ignore/best_params_intersection_svm_CNNfeatures_aggregate_energy.pickle'
    )
    io.log('Saved at {}'.format(best_params_file))

    io.log('\nSaving all cross-validation values...')
    io.save_object(cv_results,
                   'intersection_svm_CNNfeatures_aggregate_energy',
                   ignore=True)
    cv_results_file = os.path.abspath(
        './ignore/intersection_svm_CNNfeatures_aggregate_energy.pickle')
    io.log('Saved at {}'.format(cv_results_file))

    io.log('\nBEST PARAMS')
    io.log('k={}, C={} --> accuracy: {:.3f}'.format(best_params['k'],
                                                    best_params['C'],
                                                    best_accuracy))