Image resizing and cropping

Question

Hi,
I want to convert images to thumbnails with a 'standard' format - I need all images to have the same width and height.
So I need to resize and then crop the images. Is this possibe with JAI? Are there other libraries which can do this better?
I've read about ImageMagick - are the Java interfaces to ImageMagick good?
/regards, Håkan Jacobsson

Answer 1

Depending on the format of your files, you need not go into JAI. You may be able to do what you want with ImageIO.
You just need to load the image, select the part you want, then check the length to width ratio to make sure it is appropriate, if not, then adjust it as such.
If you want to get a 100, 100 thumb from a 1024, 768 image you can do this:
BufferedImage bi = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
g.drawImage(my1024x768, 0, 12, 100, 75, Color.BLACK, null);
g.dispose();please note, that to get 1024 shunk up to 100, you need to divide by 10.24, when you do the same to the height of the image, you get 75, this leaves 25 pixels--so I centered the image at 12.
to save the thumb in JPG:
File f = new File(myFileNameAndPath);
f.createFile();
ImageIO.write(bi, "JPEG", f);**WARNING** untested code.