减少java中图像的大小

Question

I want to make sure that an image in my application is not more than 200x200 px and the image size is not more than 150 kB. For example, if the file size of image is more than 150 kB i need to make it 150 kB. The image can be of type jpeg,png etc.

I have the following code for resizing an image to a given width and height

private BufferedImage resize(BufferedImage img, int newW, int newH) {
        int w = img.getWidth();
        int h = img.getHeight();
        BufferedImage dimg = new BufferedImage(newW, newH, img.getType());
        Graphics2D g = dimg.createGraphics();
        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g.drawImage(img, 0, 0, newW, newH, 0, 0, w, h, null);
        g.dispose();
        return dimg;
    }

But im not sure how to go about reducing the file size to 150 kB. How to do that in java ?.Some example would be really appreciated.

Thank You

Answer 1

就像一个选项 - 图像魔术 - 它也有一些Java的便利包装，所以你可以轻松使用它。

Answer 2

Does your question have any practical relevance or is it just theoretical?

A 200x200 pixel image with a colour depth of 24 bit will uncompressed require 117kB. If you use any reasonable JPEG encoder, it will also never exceed 150kB for such an image.

Answer 3

您只能多次重新调整图像，以低于确定的文件大小。