Class CropTransform

PATH/core/data/transforms/seg_aug_dev.py:158–259

class CropTransform(Transform):
    def __init__(
        self,
        x0: int,
        y0: int,
        w: int,
        h: int,
        orig_w: Optional[int] = None,
        orig_h: Optional[int] = None,
    ):
        """
        Args:
            x0, y0, w, h (int): crop the image(s) by img[y0:y0+h, x0:x0+w].
            orig_w, orig_h (int): optional, the original width and height
                before cropping. Needed to make this transform invertible.
        """
        super().__init__()
        self._set_attributes(locals())

    def apply_image(self, img: np.ndarray) -> np.ndarray:
        """
        Crop the image(s).

        Args:
            img (ndarray): of shape NxHxWxC, or HxWxC or HxW. The array can be
                of type uint8 in range [0, 255], or floating point in range
                [0, 1] or [0, 255].
        Returns:
            ndarray: cropped image(s).
        """
        if len(img.shape) <= 3:
            return img[self.y0 : self.y0 + self.h, self.x0 : self.x0 + self.w]
        else:
            return img[..., self.y0 : self.y0 + self.h, self.x0 : self.x0 + self.w, :]

    def apply_coords(self, coords: np.ndarray) -> np.ndarray:
        """
        Apply crop transform on coordinates.

        Args:
            coords (ndarray): floating point array of shape Nx2. Each row is
                (x, y).
        Returns:
            ndarray: cropped coordinates.
        """
        coords[:, 0] -= self.x0
        coords[:, 1] -= self.y0
        return coords

    def apply_polygons(self, polygons: list) -> list:
        """
        Apply crop transform on a list of polygons, each represented by a Nx2 array.
        It will crop the polygon with the box, therefore the number of points in the
        polygon might change.

        Args:
            polygon (list[ndarray]): each is a Nx2 floating point array of
                (x, y) format in absolute coordinates.