Java Foundation Classes in a Nutshell

the square-r oot function, which boosts midrange colors more than colors that are

dark or bright:

byte[] data = new byte[256];

for(int i = 0; i < 256; i++)

data[i] = (byte)(Math.sqrt((float)i/255.0) * 255);

ByteLookupTable table = new ByteLookupTable(0, data);

LookupOp op = new LookupOp(table, null);

BufferedImage brighterImage = op.filter(sourceImage, null);

You can blur an image using a ConvolveOp. When processing an image by convo-

lution, a pixel value in the destination image is computed from the corresponding

pixel value in the source image and the pixels that surround that pixel. A matrix of

numbers known as the ker nel is used to specify the contribution of each source

pixel to the destination pixel. To per form a simple blurring operation, you might

use a kernel like this to specify that the destination pixel is the average of the

source pixel and the eight pixels that surround that source pixel:

0.1111 0.1111 0.1111

0.1111 0.1111 0.1111

0.1111 0.1111 0.1111

Note that the sum of the values in this kernel is 1.0, which means that the destina-

tion image has the same brightness as the source image. To per form a simple blur,

use code like this:

Kernel k = new Kernel(3, 3, new float[] { .1111f, .1111f, .1111f,

.1111f, .1111f, .1111f,

.1111f, .1111f, .1111f });

ConvolveOp op = new ConvolveOp(k);

BufferedImage blurry = op.filter(sourceImage, null);

Tr ansfor mations with AffineTransfor m

As we discussed ...