MatrixToImageWriter.java

/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.client.j2se;

import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;
import java.nio.file.Path;

/**
 * Writes a {@link BitMatrix} to {@link BufferedImage}, file or stream. Provided
 * here instead of core since it depends on Java SE libraries.
 * 
 * @author Sean Owen
 */
public final class MatrixToImageWriter {

	private static final MatrixToImageConfig DEFAULT_CONFIG = new MatrixToImageConfig();

	private MatrixToImageWriter() {
	}

	/**
	 * Renders a {@link BitMatrix} as an image, where "false" bits are rendered
	 * as white, and "true" bits are rendered as black. Uses default
	 * configuration.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @return {@link BufferedImage} representation of the input
	 */
	public static BufferedImage toBufferedImage(BitMatrix matrix) {
		return toBufferedImage(matrix, DEFAULT_CONFIG);
	}

	/**
	 * As {@link #toBufferedImage(BitMatrix)}, but allows customization of the
	 * output.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param config
	 *            output configuration
	 * @return {@link BufferedImage} representation of the input
	 */
	public static BufferedImage toBufferedImage(BitMatrix matrix,
			MatrixToImageConfig config) {
		int width = matrix.getWidth();
		int height = matrix.getHeight();
		BufferedImage image = new BufferedImage(width, height,
				config.getBufferedImageColorModel());
		int onColor = config.getPixelOnColor();
		int offColor = config.getPixelOffColor();
		for (int x = 0; x < width; x++) {
			for (int y = 0; y < height; y++) {
				image.setRGB(x, y, matrix.get(x, y) ? onColor : offColor);
			}
		}
		return image;
	}

	/**
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param file
	 *            file {@link File} to write image to
	 * @throws IOException
	 *             if writes to the file fail
	 * @deprecated use {@link #writeToPath(BitMatrix, String, Path)}
	 */
	@Deprecated
	public static void writeToFile(BitMatrix matrix, String format, File file)
			throws IOException {
		writeToPath(matrix, format, file.toPath());
	}

	/**
	 * Writes a {@link BitMatrix} to a file with default configuration.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param file
	 *            file {@link Path} to write image to
	 * @throws IOException
	 *             if writes to the stream fail
	 * @see #toBufferedImage(BitMatrix)
	 */
	public static void writeToPath(BitMatrix matrix, String format, Path file)
			throws IOException {
		writeToPath(matrix, format, file, DEFAULT_CONFIG);
	}

	/**
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param file
	 *            file {@link File} to write image to
	 * @param config
	 *            output configuration
	 * @throws IOException
	 *             if writes to the file fail
	 * @deprecated use
	 *             {@link #writeToPath(BitMatrix, String, Path, MatrixToImageConfig)}
	 */
	@Deprecated
	public static void writeToFile(BitMatrix matrix, String format, File file,
			MatrixToImageConfig config) throws IOException {
		writeToPath(matrix, format, file.toPath(), config);
	}

	/**
	 * As {@link #writeToFile(BitMatrix, String, File)}, but allows
	 * customization of the output.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param file
	 *            file {@link Path} to write image to
	 * @param config
	 *            output configuration
	 * @throws IOException
	 *             if writes to the file fail
	 */
	public static void writeToPath(BitMatrix matrix, String format, Path file,
			MatrixToImageConfig config) throws IOException {
		BufferedImage image = toBufferedImage(matrix, config);
		if (!ImageIO.write(image, format, file.toFile())) {
			throw new IOException("Could not write an image of format "
					+ format + " to " + file);
		}
	}

	/**
	 * Writes a {@link BitMatrix} to a stream with default configuration.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param stream
	 *            {@link OutputStream} to write image to
	 * @throws IOException
	 *             if writes to the stream fail
	 * @see #toBufferedImage(BitMatrix)
	 */
	public static void writeToStream(BitMatrix matrix, String format,
			OutputStream stream) throws IOException {
		writeToStream(matrix, format, stream, DEFAULT_CONFIG);
	}

	/**
	 * As {@link #writeToStream(BitMatrix, String, OutputStream)}, but allows
	 * customization of the output.
	 * 
	 * @param matrix
	 *            {@link BitMatrix} to write
	 * @param format
	 *            image format
	 * @param stream
	 *            {@link OutputStream} to write image to
	 * @param config
	 *            output configuration
	 * @throws IOException
	 *             if writes to the stream fail
	 */
	public static void writeToStream(BitMatrix matrix, String format,
			OutputStream stream, MatrixToImageConfig config) throws IOException {
		BufferedImage image = toBufferedImage(matrix, config);
		if (!ImageIO.write(image, format, stream)) {
			throw new IOException("Could not write an image of format "
					+ format);
		}
	}

}