Question

在此代码上，我从mnist为zca输入一个图像（数字）。但我不确定我是应该输入整个数组还是仅输入图像。我做错了吗？

它似乎可以改变图像，但我不知道每次应该是1张图像。

另外，我需要在ZCA之前应用标准化吗？

import numpy as np
import matplotlib.pyplot as plt

from AuxMethods import flatten_matrix


def zca_whitening(inputs):
    # Correlation matrix
    sigma = np.dot(inputs, inputs.T) / inputs.shape[1]

    # Singular Value Decomposition
    U, S, V = np.linalg.svd(sigma)

    # Whitening constant, it prevents division by zero
    epsilon = 0.1

    # ZCA Whitening matrix
    ZCAMatrix = np.dot(np.dot(U, np.diag(1.0 / np.sqrt(np.diag(S) + epsilon))), U.T)

    # Data whitening
    result = np.dot(ZCAMatrix, inputs)

    print "sigma :",sigma
    #print "U",U

    # result = result.T
    return result


def apply_zca_whitening(data, show_image=False, width=28, height=28):
    aux_data = data.copy()

    print "Processing images with ZCA...Please wait!"

    for x in xrange(0, len(data[:, 0])):
        #whitened = zca_whitening(flatten_matrix(((data[x, :].T).reshape((width, height)).T).astype(np.float32)))
        whitened = zca_whitening(flatten_matrix(((data[x, :].T).reshape((width, height)).T)))

        image_aux = np.copy(whitened)
        #image_aux = image_aux.astype(np.float32)
        aux_data[x, :] = image_aux.tolist()

    if show_image is True:
        for x in xrange(0, len(aux_data[:, 0])):
            img = aux_data[x, :]
            image = np.reshape(img, (width, height))
            imgplot = plt.imshow(image, cmap=plt.gray())
            plt.show()

    print "ZCA processing :  Done!"

    return aux_data

我应该将整个数据集输入ZCA吗？

0 个答案: