summary.py 文件源码

def log_image(self, step, tag, val):
        '''
        Write an image event.

        :param int step: Time step (x-axis in TensorBoard graphs)
        :param str tag: Label for this value
        :param numpy.ndarray val: Image in RGB format with values from
            0 to 255; a 3-D array with index order (row, column, channel).
            `val.shape[-1] == 3`
        '''
        # TODO: support floating-point tensors, 4-D tensors, grayscale
        if len(val.shape) != 3:
            raise ValueError('`log_image` value should be a 3-D tensor, instead got shape %s' %
                             (val.shape,))
        if val.shape[2] != 3:
            raise ValueError('Last dimension of `log_image` value should be 3 (RGB), '
                             'instead got shape %s' %
                             (val.shape,))
        fakefile = StringIO()
        png.Writer(size=(val.shape[1], val.shape[0])).write(
            fakefile, val.reshape(val.shape[0], val.shape[1] * val.shape[2]))
        encoded = fakefile.getvalue()
        # https://tensorflow.googlesource.com/tensorflow/+/master/tensorflow/core/framework/summary.proto
        RGB = 3
        image = Summary.Image(height=val.shape[0], width=val.shape[1],
                              colorspace=RGB, encoded_image_string=encoded)
        summary = Summary(value=[Summary.Value(tag=tag, image=image)])
        self._add_event(step, summary)