def predict_batch_from_model(patches, model):
    """Predict which pixels are tumor.

    Parameters
    ----------
    patch: batch_sizex256x256x3, rgb image

    model: keras model

    Returns
    --------
    output: prediction: 256x256x1, per-pixel tumor probability
    """
    predictions = model.predict(patches)
    predictions = predictions[:, :, :, 1]
    return predictions