mindspore.dataset.vision.LinearTransformation
- class mindspore.dataset.vision.LinearTransformation(transformation_matrix, mean_vector)[源代码]
使用指定的变换方阵和均值向量对输入numpy.ndarray图像进行线性变换。
先将输入图像展平为一维,从中减去均值向量,然后计算其与变换方阵的点积,最后再变形回原始shape。
参数:
transformation_matrix (numpy.ndarray) - shape为(D, D)的变换方阵,其中
\(D = C \times H \times W\) 。
mean_vector (numpy.ndarray) - shape为(D,)的均值向量,其中
\(D = C \times H \times W\) 。
异常:
TypeError - 当 transformation_matrix 的类型不为
numpy.ndarray
。TypeError - 当 mean_vector 的类型不为
numpy.ndarray
。
- 支持平台:
CPU
样例:
>>> import numpy as np >>> from mindspore.dataset.transforms import Compose >>> >>> height, width = 32, 32 >>> dim = 3 * height * width >>> transformation_matrix = np.ones([dim, dim]) >>> mean_vector = np.zeros(dim) >>> transforms_list = Compose([vision.Decode(to_pil=True)), ... vision.Resize((height,width)), ... vision.ToTensor(), ... vision.LinearTransformation(transformation_matrix, mean_vector)]) >>> # apply the transform to dataset through map function >>> image_folder_dataset = image_folder_dataset.map(operations=transforms_list, ... input_columns="image")