pypher.py 文件源码

def imresample(image, source_pscale, target_pscale, interp_order=1):
    """
    Resample data array from one pixel scale to another

    The resampling ensures the parity of the image is conserved
    to preserve the centering.

    Parameters
    ----------
    image : `numpy.ndarray`
        Input data array
    source_pscale : float
        Pixel scale of ``image`` in arcseconds
    target_pscale : float
        Pixel scale of output array in arcseconds
    interp_order : int, optional
        Spline interpolation order [0, 5] (default 1: linear)

    Returns
    -------
    output : `numpy.ndarray`
        Resampled data array

    """
    old_size = image.shape[0]
    new_size_raw = old_size * source_pscale / target_pscale
    new_size = int(np.ceil(new_size_raw))

    if new_size > 10000:
        raise MemoryError("The resampling will yield a too large image. "
                          "Please resize the input PSF image.")

    # Chech for parity
    if (old_size - new_size) % 2 == 1:
        new_size += 1

    ratio = new_size / old_size

    return zoom(image, ratio, order=interp_order) / ratio**2