fitsimage.py 文件源码

def zoom(self, newsize, order=1):
        """
        Zoom the image to the specified ``newsize``, meanwhile the header
        information will be updated accordingly to preserve the FoV coverage.

        NOTE
        ----
        The image aspect ratio cannot be changed.

        Parameters
        ----------
        newsize : (Nx, Ny) or N
            The size of the zoomed image.
        order : int, optional
            The interpolation order, default: 1
        """
        try:
            Nx2, Ny2 = newsize
        except TypeError:
            Nx2 = Ny2 = newsize
        zoom = ((Ny2+0.1)/self.Ny, (Nx2+0.1)/self.Nx)
        if abs(zoom[0] - zoom[1]) > 1e-3:
            raise RuntimeError("image aspect ratio cannot be changed")

        pixelsize_old = self.pixelsize
        self.image = ndimage.zoom(self.image, zoom=zoom, order=order)
        self.pixelsize = pixelsize_old * (self.Nx / Nx2)
        return self.image