org.gbif.portal.util.image.ImageUtils.java Source code

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Here is the source code for org.gbif.portal.util.image.ImageUtils.java

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/***************************************************************************
 * Copyright (C) 2005 Global Biodiversity Information Facility Secretariat.
 * All Rights Reserved.
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 ***************************************************************************/
package org.gbif.portal.util.image;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.imageio.ImageIO;
import javax.media.jai.JAI;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.net.URL;

/**
 * Utilities for dealing with images
 *
 * @author dhobern
 */
public class ImageUtils {

    protected static Log logger = LogFactory.getLog(ImageUtils.class);

    /**
     * Return true if the URL resolves to an image (rather than e.g. a web
     * page or application launcher.
     *
     * @param url
     * @return true if image is loadable
     */
    public static boolean isImageLoadable(String url) {
        try {
            RenderedImage image = ImageIO.read(new URL(url));
            image.getMinX();
        } catch (Exception e) {
            return false;
        } catch (Throwable e) {
            logger.warn("JAI is not functioning correctly - Ignoring: " + e.getMessage());
            // happens when the JAI is not working.... no reason to know it is bust
            return true;
        }
        return true;
    }

    /**
     * Return true if the URL resolves to an image (rather than e.g. a web
     * page or application launcher.
     *
     * @param url
     * @return image width and height in a int array
     */
    public static int[] findImageDimensions(String url) {
        try {
            RenderedImage image = ImageIO.read(new URL(url));
            return new int[] { image.getWidth(), image.getHeight() };
        } catch (Exception e) {
            logger.error("Problem loading image from url: " + url);
            logger.error(e.getMessage(), e);
            return null;
        }
    }

    /**
     * Scales the image to the specified height and width in pixels.
     *
     * @param url
     * @param width
     * @param height
     * @param fileOutputUrl
     * @param format
     * @return true if image is loadable
     */
    public static boolean scaleImageAndWriteToFile(String url, int width, int height, String fileOutputUrl,
            String format) {
        try {
            RenderedImage image = ImageIO.read(new URL(url));
            scaleImage(image, width, height);
            ImageIO.write(image, format, new File(fileOutputUrl));
        } catch (Exception e) {
            return false;
        }
        return true;
    }

    /**
     * Scales the image to the specified height and width in pixels.
     *
     * @param url
     * @param width
     * @param height
     * @param fileOutputUrl
     * @param format
     * @return true if image is loadable
     */
    public static byte[] scaleImageFromStream(InputStream imageStream, int width, int height, String format) {
        try {
            BufferedImage bufferedImage = ImageIO.read(imageStream);
            //         RenderedImage image = JAI.create("stream", imageStream);
            scaleImage(bufferedImage, width, height);

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            BufferedOutputStream bos = new BufferedOutputStream(baos);
            //         JAI.create("stream", image, bos, format);

            //         ImageIO.
            ImageIO.write(bufferedImage, format, bos);

            return baos.toByteArray();
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * Scale an image to the required size
     *
     * @param image
     * @param width
     * @param height
     */
    public static void scaleImage(RenderedImage image, int width, int height) {

        int originalWidth = image.getWidth();
        int originalHeight = image.getHeight();

        Float heightScale = 1.0f;
        Float widthScale = 1.0f;

        if (originalHeight > height) {
            heightScale = (float) height / (float) originalHeight;
        }
        if (originalWidth > width) {
            widthScale = (float) width / (float) originalWidth;
        }

        if (heightScale < widthScale) {
            widthScale = heightScale;
        } else {
            heightScale = widthScale;
        }
        image = JAI.create("scale", image, widthScale, heightScale);
    }
}