使用宽高比和裁剪中心图像调整C＃中的图像，使其没有间隙

I'm trying to resize user uploaded images to a landscape dimensions e.g. 450w and 250h while maintaining aspect ratio, but to avoid resized images like portrait images having gaps on the side I would like to crop the centre of the image to fill the resized dimensions.I'm trying to resize user uploaded images to a