Javaテクニカルサンプル集

Image image = イメージオブジェクトはすでに取得できているものとする
int width = 元イメージ幅
int height = 元イメージ高さ
int rwidth = 変換イメージ幅
int rheight = 変換イメージ高さ

BufferedImage bimg= new BufferedImage(width,height,BufferedImage.TYPE_3BYTE_BGR);
Graphics gimg = bimg.createGraphics();
gimg.drawImage((Image)image,0,0,null);  // BufferedImageに描画させる
    
double scalew = (double)rc.width/(double)width;
double scaleh = (double)rc.height/(double)height;
AffineTransformOp atOp = null;
atOp = new AffineTransformOp(AffineTransform.getScaleInstance(scalew, scaleh),
   AffineTransformOp.TYPE_BILINEAR);
          
BufferedImage dest2 = new BufferedImage(rc.width, rc.height, bimg.getType()); 
int size = (int)(1.0/scalew);
float[] kernelData = new float[size*size];
for (int i = 0; i < size * size; i++) {
 kernelData[i] = 1.0f / size / size;
}

Kernel kernel = new Kernel(size, size, kernelData);
ConvolveOp coOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); 
BufferedImage inter = new BufferedImage(width, height, bimg.getType()); 
coOp.filter(bimg, inter);
atOp.filter(inter, dest2);