I don't think so, basically what you do is to reduce the amount of information in the image which required 4000x4000 pixel to suddenly fit in a 400x400, so you loose a lot of information (details). The only way to improve the details of the text is to add it after you have resized the images so it is made to fit the 400x400 size. But regardless of how you do it, small text on a 400x400 will always look blurred simply due to the lack of pixels in the image, so its a matter of just trying different font sizes until you are happy..