Java image scaling improve quality?

Question

I am currently scaling images using the following code.

Image scaledImage = img.getScaledInstance( width, int height, Image.SCALE_SMOOTH);
BufferedImage imageBuff = new BufferedImage(width, scaledImage.getHeight(null), BufferedImage.TYPE_INT_RGB);
Graphics g = imageBuff.createGraphics();
g.drawImage(scaledImage, 0, 0, new Color(0, 0, 0), null);
g.dispose();
ImageIO.write(imageBuff, "jpg", newFile);

Anyone have an idea of a better way of scaling an image and getting better quality results, or even any help on improving my current code to get better quality output.

You could look at the `SCALE_*` fields on http://docs.oracle.com/javase/7/docs/api/java/awt/Image.html — Kninnug, Apr 12 '13 at 15:48
I think it will be helpful http://ebhor.com/high-quality-thumbnail-generation-in-java/ — xrcwrn, Mar 13 '14 at 08:08
I've answered you question here in detail: http://stackoverflow.com/questions/3967731/how-to-improve-the-performance-of-g-drawimage-method-for-resizing-images/32266733#32266733 — nemo, Oct 24 '15 at 10:17

score 3 · Accepted Answer · answered Apr 12 '13 at 16:03

You can use Affine Transorm

public static BufferedImage getScaledImage(BufferedImage image, int width, int height) throws IOException {
    int imageWidth  = image.getWidth();
    int imageHeight = image.getHeight();

    double scaleX = (double)width/imageWidth;
    double scaleY = (double)height/imageHeight;
    AffineTransform scaleTransform = AffineTransform.getScaleInstance(scaleX, scaleY);
    AffineTransformOp bilinearScaleOp = new AffineTransformOp(scaleTransform, AffineTransformOp.TYPE_BILINEAR);

    return bilinearScaleOp.filter(
        image,
        new BufferedImage(width, height, image.getType()));
}

Also try this Example .

Also Try java-image-scaling library

Got the best results using the java-image-scaling library. – JCS Apr 17 '13 at 11:58 — JCS, Apr 17 '13 at 11:58

score 2 · Answer 2 · answered Apr 12 '13 at 15:58

2

You might want to look at this image scaling library. It has algorithms like bicubic and Lanczos and also an unsharp filter.

answered Apr 12 '13 at 15:58

Eelke

20,897
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score 1 · Answer 3 · answered Apr 12 '13 at 15:56

1

Try avoiding Image.getScaledInstance().

answered Apr 12 '13 at 15:56

Stefan

12,108
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Java image scaling improve quality?

3 Answers3

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