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Re: Can you resize with BufferedImage

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On Wed, 12 Apr 2017 10:34:04 +0200, Cecil Westerhof wrote:

> In my code I have the following code:
>     dest = image.getSubimage(x, y, dispWidth, dispHeight);
> 
> This is the part that I want to select, but I want to resize it at the
> same time. In this case I would like to scale to 50%.
> How should I do that?

Use an AffineTransform. 

The image resizing code should look something like this fragment:

   AffineTransform at = new AffineTransform();
   at.scale(scale, scale);
   AffineTransformOp op = new AffineTransformOp(at,
                              AffineTransformOp.TYPE_BICUBIC);
   Double nw = new Double(w * scale);
   Double nh = new Double(h * scale);
   om = new BufferedImage(nw.intValue(),
                          nh.intValue(),
                          BufferedImage.TYPE_3BYTE_BGR);
   op.filter(im, om);

where:
im    is a BufferedImage containing the old image
om    is a BufferedImage to hold the modified image
scale is a double containing the required scaling factor

I'm scaling images to a width of 400 pixels, so I calculate scale as 
400.0 / image_width. You would just set scale to 0.5. I want to keep the 
image proportion, so I use the same scale value for both width and height.


-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

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Thread

Can you resize with BufferedImage Cecil Westerhof <Cecil@decebal.nl> - 2017-04-12 10:34 +0200
  Re: Can you resize with BufferedImage Martin Gregorie <martin@address-in-sig.invalid> - 2017-04-12 10:18 +0000
    Re: Can you resize with BufferedImage Cecil Westerhof <Cecil@decebal.nl> - 2017-04-12 14:08 +0200
      Re: Can you resize with BufferedImage Martin Gregorie <martin@address-in-sig.invalid> - 2017-04-12 13:06 +0000
        Re: Can you resize with BufferedImage Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2017-04-12 10:05 -0500
          Re: Can you resize with BufferedImage Eric Douglas <e.d.programmer@gmail.com> - 2017-04-12 08:20 -0700
            Re: Can you resize with BufferedImage Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2017-04-13 11:10 -0500
          Re: Can you resize with BufferedImage Martin Gregorie <martin@address-in-sig.invalid> - 2017-04-12 16:13 +0000

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