Function Differences with tf.image.rgb_to_grayscale

tf.image.rgb_to_grayscale(
    images,
    name=None
)

class mindspore.dataset.vision.ConvertColor(
    convert_mode
)

# The following implements ConvertColor with MindSpore.
import numpy as np
import mindspore.dataset as ds
from mindspore.dataset.vision import ConvertMode

image = np.random.random((28, 28, 3)).astype(np.float32)
result = ds.vision.ConvertColor(ConvertMode.COLOR_RGB2GRAY)(image)
print(result.shape)
# (28, 28)

# The following implements rgb_to_grayscale with TensorFlow.
import tensorflow as tf

image = tf.random.normal((28, 28, 3))
result = tf.image.rgb_to_grayscale(image)
print(result.shape)
# (28, 28, 1)