001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.image.annotation.evaluation.datasets.cifar;
031
032import org.openimaj.image.FImage;
033import org.openimaj.image.ImageUtilities;
034import org.openimaj.image.annotation.evaluation.datasets.cifar.BinaryReader;
035
036/**
037 * {@link BinaryReader} for CIFAR data that converts the encoded rgb pixel
038 * values into an {@link FImage} (by unweighted averaging).
039 *
040 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
041 *
042 */
043public class FImageReader implements BinaryReader<FImage> {
044        int width;
045        int height;
046
047        /**
048         * Construct with the given image height and width. The byte arrays given to
049         * {@link #read(byte[])} must be 3 * height * width in length.
050         *
051         * @param width
052         *            the image width
053         * @param height
054         *            the image height
055         */
056        public FImageReader(int width, int height) {
057                this.width = width;
058                this.height = height;
059        }
060
061        @Override
062        public final FImage read(final byte[] record) {
063                final FImage image = new FImage(width, height);
064                final float[][] p = image.pixels;
065                for (int y = 0, j = 0; y < height; y++) {
066                        for (int x = 0; x < width; x++, j++) {
067                                final float r = ImageUtilities.BYTE_TO_FLOAT_LUT[record[j] & 0xff];
068                                final float g = ImageUtilities.BYTE_TO_FLOAT_LUT[record[j] & 0xff];
069                                final float b = ImageUtilities.BYTE_TO_FLOAT_LUT[record[j] & 0xff];
070                                p[y][x] = (r + g + b) / 3;
071                        }
072                }
073                return image;
074        }
075}