image.py 文件源码

def fit(self, X,
            augment=False,
            rounds=1,
            seed=None):
        '''Required for featurewise_center, featurewise_std_normalization
        and zca_whitening.

        # Arguments
            X: Numpy array, the data to fit on.
            augment: whether to fit on randomly augmented samples
            rounds: if `augment`,
                how many augmentation passes to do over the data
            seed: random seed.
        '''
        if seed is not None:
            np.random.seed(seed)

        X = np.copy(X)
        if augment:
            aX = np.zeros(tuple([rounds * X.shape[0]] + list(X.shape)[1:]))
            for r in range(rounds):
                for i in range(X.shape[0]):
                    aX[i + r * X.shape[0]] = self.random_transform(X[i])
            X = aX

        if self.featurewise_center:
            self.mean = np.mean(X, axis=0)
            X -= self.mean

        if self.featurewise_std_normalization:
            self.std = np.std(X, axis=0)
            X /= (self.std + 1e-7)

        if self.zca_whitening:
            flatX = np.reshape(X, (X.shape[0], X.shape[1] * X.shape[2] * X.shape[3]))
            sigma = np.dot(flatX.T, flatX) / flatX.shape[1]
            U, S, V = linalg.svd(sigma)
            self.principal_components = np.dot(np.dot(U, np.diag(1. / np.sqrt(S + 10e-7))), U.T)