def _remove_white_background(image):
    """Remove white background in the preview image."""
    from PIL import ImageMath, Image
    if image.mode == "RGBA":
        bands = image.split()
        a = bands[3]
        rgb = [
            ImageMath.eval(
                'convert('
                'float(x + a - 255) * 255.0 / float(max(a, 1)) * '
                'float(min(a, 1)) + float(x) * float(1 - min(a, 1))'
                ', "L")',
                x=x, a=a
            )
            for x in bands[:3]
        ]
        return Image.merge(bands=rgb + [a], mode="RGBA")

    return image
Remove white background in the preview image.