Class ThresholdIntensity

monai/transforms/intensity/array.py:951–979

Filter the intensity values of whole image to below threshold or above threshold. And fill the remaining parts of the image to the `cval` value. Args: threshold: the threshold to filter intensity values. above: filter values above the threshold or below the threshold, d

class ThresholdIntensity(Transform):
    """
    Filter the intensity values of whole image to below threshold or above threshold.
    And fill the remaining parts of the image to the `cval` value.

    Args:
        threshold: the threshold to filter intensity values.
        above: filter values above the threshold or below the threshold, default is True.
        cval: value to fill the remaining parts of the image, default is 0.
    """

    backend = [TransformBackends.TORCH, TransformBackends.NUMPY]

    def __init__(self, threshold: float, above: bool = True, cval: float = 0.0) -> None:
        if not isinstance(threshold, (int, float)):
            raise ValueError(f"threshold must be a float or int number, got {type(threshold)} {threshold}.")
        self.threshold = threshold
        self.above = above
        self.cval = cval

    def __call__(self, img: NdarrayOrTensor) -> NdarrayOrTensor:
        """
        Apply the transform to `img`.
        """
        img = convert_to_tensor(img, track_meta=get_track_meta())
        mask = img > self.threshold if self.above else img < self.threshold
        res = where(mask, img, self.cval)
        res, *_ = convert_data_type(res, dtype=img.dtype)
        return res


class ScaleIntensityRange(Transform):