com.domenicseccareccia.jpegautorotate.imaging.JpegImageTransform Maven / Gradle / Ivy

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/**
 * Copyright (c) 2019-2021 Domenic Seccareccia and contributors
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.domenicseccareccia.jpegautorotate.imaging;

import com.domenicseccareccia.jpegautorotate.JpegAutorotateException;
import org.apache.commons.imaging.formats.tiff.constants.TiffTagConstants;

import java.awt.image.BufferedImage;

final class JpegImageTransform {

    /**
     * Not intended for instantiation.
     */
    private JpegImageTransform() {
        throw new IllegalStateException("Not intended for instantiation.");
    }

    /**
     * Attempts to automatically rotate {@code JpegImage} {@code image}.
     *
     * @param jpegImage
     *              An instance of {@code JpegImage}.
     * @throws JpegAutorotateException
     *              In the event the {@code JpegImage} is unable to be rotated.
     */
    protected static void rotateImage(JpegImage jpegImage) throws JpegAutorotateException {
        BufferedImage image = rotateAndFlip(jpegImage.getImage(), jpegImage.getMetadata().getOrientation());

        jpegImage.setImage(image);
    }

    /**
     * Attempts to automatically rotate {@code JpegImage} metadata {@code ExifThumbnail} image.
     *
     * @param metadata
     *              An instance of {@code JpegImageMetadata}.
     * @throws JpegAutorotateException
     *              In the event the {@code ExifThumbnail} image is unable to be rotated.
     */
    protected static void rotateThumbnail(JpegImageMetadata metadata) throws JpegAutorotateException {
        BufferedImage bufferedImage = rotateAndFlip(metadata.getThumbnail(), metadata.getOrientation());

        metadata.setThumbnail(bufferedImage);
    }

    /**
     * Attempts to determine and process the transformation (rotate and flip) required for the {@code JpegImage}.
     * Transformation is depends on the EXIF {@code Orientation} metadata tag value.
     * 
     * {@code JpegImage} may not contain the EXIF {@code Orientation} metadata tag.
     * 
     *
     * @param image
     *              A {@code BufferedImage} containing image data.
     * @param orientation
     *              A EXIF {@code Orientation} metadata tag value.
     * @return If successful, a {@code BufferedImage} containing transformed image data.
     * @throws JpegAutorotateException
     *            In the event the {@code Orientation} value is unknown.
     */
    private static BufferedImage rotateAndFlip(BufferedImage image, final int orientation) throws JpegAutorotateException {
        switch (orientation) {
            case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL:
                flipHorizontally(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_ROTATE_180:
                flipVertically(image);
                flipHorizontally(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_MIRROR_VERTICAL:
                flipVertically(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL_AND_ROTATE_270_CW:
                image = rotate90CW(image);
                flipHorizontally(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_ROTATE_90_CW:
                image = rotate90CW(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_MIRROR_HORIZONTAL_AND_ROTATE_90_CW:
                image = rotate90CCW(image);
                flipHorizontally(image);
                break;
            case TiffTagConstants.ORIENTATION_VALUE_ROTATE_270_CW:
                image = rotate90CCW(image);
                break;
            default:
                throw new JpegAutorotateException("JPEG image has an unknown EXIF Orientation metadata tag value: " + orientation);
        }

        return image;
    }

    /**
     * Flips a {@code BufferedImage} vertically.
     *
     * @param image
     *              A {@code BufferedImage} containing image data.
     */
    private static void flipVertically(BufferedImage image) {
        for (int i = 0; i < image.getHeight()/2; i++) {
            int[] upperRow = image.getRGB(0, i, image.getWidth(), 1, null, 0, image.getWidth());
            int[] lowerRow = image.getRGB(0, image.getHeight() - 1 - i, image.getWidth(), 1, null, 0, image.getWidth());

            image.setRGB(0, image.getHeight() - 1 - i, image.getWidth(), 1, upperRow, 0, image.getWidth());
            image.setRGB(0,i, image.getWidth(), 1, lowerRow, 0, image.getWidth());
        }
    }

    /**
     * Flips a {@code BufferedImage} horizontally.
     *
     * @param image
     *              A {@code BufferedImage} containing image data.
     */
    private static void flipHorizontally(BufferedImage image) {
        for (int i = 0; i < image.getHeight(); i++) {
            for (int j = 0; j < image.getWidth()/2; j++) {
                int temp = image.getRGB(j, i);

                image.setRGB(j, i, image.getRGB(image.getWidth()-(1+j), i));
                image.setRGB(image.getWidth()-(1+j), i, temp);
            }
        }
    }

    /**
     * Rotates a {@code BufferedImage} 90 degrees clockwise.
     *
     * @param image
     *              A {@code BufferedImage} containing image data.
     * @return A {@code BufferedImage} rotated containing rotated image data.
     */
    private static BufferedImage rotate90CW(BufferedImage image) {
        BufferedImage tempImage = new BufferedImage(image.getHeight(), image.getWidth(), image.getType());

        for (int i = 0; i < image.getHeight(); i++) {
            for (int j = 0; j < image.getWidth(); j++) {
                tempImage.setRGB(tempImage.getWidth()-1-i, j, image.getRGB(j, i));
            }
        }

        return tempImage;
    }

    /**
     * Rotates a {@code BufferedImage} 90 degrees counter clockwise.
     *
     * @param image
     *              A {@code BufferedImage} containing image data.
     * @return A {@code BufferedImage} rotated containing rotated image data.
     */
    private static BufferedImage rotate90CCW(BufferedImage image) {
        BufferedImage tempImage = new BufferedImage(image.getHeight(), image.getWidth(), image.getType());

        for (int i = 0; i < image.getHeight(); i++) {
            for (int j = 0; j < image.getWidth(); j++) {
                tempImage.setRGB(i, tempImage.getHeight()-1-j, image.getRGB(j, i));
            }
        }

        return tempImage;
    }

}