Example usage for javax.imageio ImageReadParam setDestination

Introduction

In this page you can find the example usage for javax.imageio ImageReadParam setDestination.

Prototype

public void setDestination(BufferedImage destination) 

Source Link

Document

Supplies a BufferedImage to be used as the destination for decoded pixel data.

Usage

From source file:org.jimcat.services.imagemanager.ImageUtil.java

/**
 * this methode will load given image using tiles (saving memory)
 * /*from  w ww.java 2 s . c om*/
 * this strategie is spliting the original image up into smaller parts
 * called tiles. Those tiles are downscaled one by one using given quality.
 * This results int probably best possible quality but may cost a lot of
 * time.
 * 
 * @param reader -
 *            the reader to load image from
 * @param size -
 *            the resulting image size
 * @param quality -
 *            the quality used for necessary rendering
 * @return the image as buffered image
 * @throws IOException
 */
@SuppressWarnings("unused")
private static BufferedImage loadImageWithTiles(ImageReader reader, Dimension size, ImageQuality quality)
        throws IOException {

    // the image buffer used to load tiles
    ImageTypeSpecifier imageSpec = reader.getImageTypes(0).next();
    BufferedImage tile = imageSpec.createBufferedImage(IMAGE_TILE_SIZE.width, IMAGE_TILE_SIZE.height);

    // the image the result is rendered into
    BufferedImage result = new BufferedImage(size.width, size.height, BufferedImage.TYPE_INT_ARGB);
    Graphics2D g = result.createGraphics();
    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, quality.getHint());

    // prepaire image reader parameter
    ImageReadParam param = reader.getDefaultReadParam();
    param.setDestination(tile);

    // count tiles
    int width = reader.getWidth(0);
    int height = reader.getHeight(0);
    int numX = (int) Math.ceil(width / (float) IMAGE_TILE_SIZE.width);
    int numY = (int) Math.ceil(height / (float) IMAGE_TILE_SIZE.height);

    float aspectX = (float) IMAGE_TILE_SIZE.width / width;
    float aspectY = (float) IMAGE_TILE_SIZE.height / height;

    // target tile dimension
    int targetTileWidth = (int) (size.width * aspectX);
    int targetTileHeight = (int) (size.height * aspectY);

    // load tiles
    Rectangle sourceRegion = new Rectangle();
    Rectangle targetRegion = new Rectangle();
    for (int i = 0; i < numX; i++) {
        // line increment
        sourceRegion.x = i * IMAGE_TILE_SIZE.width;
        sourceRegion.width = Math.min(IMAGE_TILE_SIZE.width, width - sourceRegion.x);
        targetRegion.x = i * targetTileWidth;
        targetRegion.width = Math.min(targetTileWidth, size.width - targetRegion.x);
        for (int j = 0; j < numY; j++) {
            // row increment
            sourceRegion.y = j * IMAGE_TILE_SIZE.height;
            sourceRegion.height = Math.min(IMAGE_TILE_SIZE.height, height - sourceRegion.y);
            targetRegion.y = j * targetTileHeight;
            targetRegion.height = Math.min(targetTileHeight, size.height - targetRegion.y);

            // performe read
            param.setSourceRegion(sourceRegion);
            reader.read(0, param);

            // insert into resulting image
            int dx1 = targetRegion.x;
            int dx2 = targetRegion.x + targetRegion.width;
            int dy1 = targetRegion.y;
            int dy2 = targetRegion.y + targetRegion.height;

            g.drawImage(tile, dx1, dy1, dx2, dy2, 0, 0, sourceRegion.width, sourceRegion.height, null);
        }
    }

    // finish drawing
    g.dispose();

    // return result
    return result;
}

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