tf-keras-skeleton.py 文件源码

def apply_transform(x,
                            transform_matrix,
                            channel_axis=0,
                            fill_mode='nearest',
                            cval=0.):
          """Apply the image transformation specified by a matrix.

          Arguments:
              x: 2D numpy array, single image.
              transform_matrix: Numpy array specifying the geometric transformation.
              channel_axis: Index of axis for channels in the input tensor.
              fill_mode: Points outside the boundaries of the input
                  are filled according to the given mode
                  (one of `{'constant', 'nearest', 'reflect', 'wrap'}`).
              cval: Value used for points outside the boundaries
                  of the input if `mode='constant'`.

          Returns:
              The transformed version of the input.
          """
          x = np.rollaxis(x, channel_axis, 0)
          final_affine_matrix = transform_matrix[:2, :2]
          final_offset = transform_matrix[:2, 2]
          channel_images = [
              ndi.interpolation.affine_transform(
                  x_channel,
                  final_affine_matrix,
                  final_offset,
                  order=0,
                  mode=fill_mode,
                  cval=cval) for x_channel in x
          ]
          x = np.stack(channel_images, axis=0)
          x = np.rollaxis(x, 0, channel_axis + 1)
          return x