Re: [JAVA2D] How to create a smaller BufferedImage from larger one - help wanted

[Eric Kolotyluk]

Thanks Jim for welcome and the tip, but I cannot see how to get a WriteableRaster that is scaled, or how to scale a WritableRaster - other that to do the interpolation myself, but that would defeat the purpose of a high class library of graphics.

Yes, I'm not working with GIF but with PNG. My goal is simply to have as exact as possible a scaled image in a second BufferedImage as possible. This does not seem to be possible with the current Graphics2D API. I haven't looked at the JAI API yet, could there be something there to do the trick?

Cheers, Eric

Jim Graham wrote:

Hi Eric,

BufferedImage questions are always welcome on the Java2D list.

You might have better luck getting the ColorModel, asking it to
create you a compatible raster, and then using the BufferedImage
constructor that takes a ColorModel and a Raster.

But, if the original image was a GIF then the image returned from
ImageIO would be an indexed image and you might not want to have
a compatible image for the reduced version as that would involve
some dithering - so perhaps it isn't always the best solution to
request an image in the same format as the original.

In this particular case, I'm guessing that you weren't working with
a GIF since reading a GIF would not tend to return a CUSTOM image...

                                ...jim

--On Monday, March 03, 2003 20:56:18 -0800 Eric Kolotyluk
<[EMAIL PROTECTED]> wrote:
  

Where's the border for asking question and posting topics. For quite a
while I didn't realize that JAI was a separate package to be downloaded
and asked a lot of Graphic2D questions on the JAI list, but got some
answers by nice people. But then I noticed that some people were
concerned about the types of questions being posted on JAI. Anyway,
please let me know which list the following question best belongs in,

I have a situation where I need to make a smaller buffered image from a
larger one, and I want it to have the same type and colour model, but
different dimensions. Can this be done, and if so how?

Currently I do something like

BufferedImage original = ImiageIO.read(file.png);
BufferedImage printable = new BufferImage(
    (int)(scale * original.getWidth()),
    (int)(scale * original.getHeight()),
    BufferedImage.TYPE_3BYTE_BRG);

AffineTransform transform = new AffineTransform();
transform.scale(scale, scale);

Graphics2D g = printable.createGraphic();
g.drawImage(original, transform, null);

The problem is that original is TYPE_CUSTOM and the Java runtime won't
let me create a BufferedImage of type custom.

Any help would be appreciated.

Cheers, Eric