keras-team/keras · error · ValueError

Invalid channel size: expected 3 (RGB) or 1 (Grayscale). Rec

Error message

Invalid channel size: expected 3 (RGB) or 1 (Grayscale). Received input with shape: images.shape={images.shape}

What it means

Error "Invalid channel size: expected 3 (RGB) or 1 (Grayscale). Received input with shape: images.shape={images.shape}" thrown in keras-team/keras.

Source

Thrown at keras/src/backend/openvino/image.py:64

    "lanczos5": "lanczos5",
}
ALL_RESIZE_INTERPOLATIONS = tuple(RESIZE_INTERPOLATIONS) + tuple(
    LANCZOS_INTERPOLATIONS
)


def rgb_to_grayscale(images, data_format=None):
    images = get_ov_output(images)
    data_format = backend.standardize_data_format(data_format)
    if images.get_partial_shape().rank not in (3, 4):
        raise ValueError(
            "Invalid images rank: expected rank 3 (single image) "
            "or rank 4 (batch of images). Received input with shape: "
            f"images.shape={images.shape}"
        )
    channel_axis = -3 if data_format == "channels_first" else -1
    if images.shape[channel_axis] not in (1, 3):
        raise ValueError(
            "Invalid channel size: expected 3 (RGB) or 1 (Grayscale). "
            f"Received input with shape: images.shape={images.shape}"
        )

    if images.shape[channel_axis] == 3:
        original_type = images.get_element_type()
        rgb_weights = ov_opset.constant(
            [0.2989, 0.5870, 0.1140], dtype=original_type
        ).output(0)
        if data_format == "channels_first":
            rgb_weights = ov_opset.unsqueeze(rgb_weights, axes=[-2, -1]).output(
                0
            )
        grayscales = ov_opset.multiply(images, rgb_weights).output(0)
        grayscales = ov_opset.reduce_sum(
            grayscales, reduction_axes=[channel_axis]
        ).output(0)
        grayscales = ov_opset.unsqueeze(grayscales, axes=[channel_axis]).output(

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/openvino/image.py:64 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/14ec8104a115a95a. Report an issue: GitHub.