/*

   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 org.apache.batik.ext.awt.image.codec.tiff;

import java.awt.image.RenderedImage;
import java.io.IOException;

import org.apache.batik.ext.awt.image.codec.util.ImageDecodeParam;
import org.apache.batik.ext.awt.image.codec.util.ImageDecoderImpl;
import org.apache.batik.ext.awt.image.codec.util.SeekableStream;

/**
 * A baseline TIFF reader. The reader has some functionality in addition to
 * the baseline specifications for Bilevel images, for which the group 3 and
 * group 4 decompression schemes have been implemented. Support for LZW
 * decompression has also been added. Support for Horizontal differencing
 * predictor decoding is also included, when used with LZW compression.
 * However, this support is limited to data with bitsPerSample value of 8.
 * When reading in RGB images, support for alpha and extraSamples being
 * present has been added. Support for reading in images with 16 bit samples
 * has been added. Support for the SampleFormat tag (signed samples as well
 * as floating-point samples) has also been added. In all other cases, support
 * is limited to Baseline specifications.
 *
 * @version $Id$
 */
public class TIFFImageDecoder extends ImageDecoderImpl {

    // All the TIFF tags that we care about
    public static final int TIFF_IMAGE_WIDTH                = 256;
    public static final int TIFF_IMAGE_LENGTH               = 257;
    public static final int TIFF_BITS_PER_SAMPLE            = 258;
    public static final int TIFF_COMPRESSION                = 259;
    public static final int TIFF_PHOTOMETRIC_INTERPRETATION = 262;
    public static final int TIFF_FILL_ORDER                 = 266;
    public static final int TIFF_STRIP_OFFSETS              = 273;
    public static final int TIFF_SAMPLES_PER_PIXEL          = 277;
    public static final int TIFF_ROWS_PER_STRIP             = 278;
    public static final int TIFF_STRIP_BYTE_COUNTS          = 279;
    public static final int TIFF_X_RESOLUTION               = 282;
    public static final int TIFF_Y_RESOLUTION               = 283;
    public static final int TIFF_PLANAR_CONFIGURATION       = 284;
    public static final int TIFF_T4_OPTIONS                 = 292;
    public static final int TIFF_T6_OPTIONS                 = 293;
    public static final int TIFF_RESOLUTION_UNIT            = 296;
    public static final int TIFF_PREDICTOR                  = 317;
    public static final int TIFF_COLORMAP                   = 320;
    public static final int TIFF_TILE_WIDTH                 = 322;
    public static final int TIFF_TILE_LENGTH                = 323;
    public static final int TIFF_TILE_OFFSETS               = 324;
    public static final int TIFF_TILE_BYTE_COUNTS           = 325;
    public static final int TIFF_EXTRA_SAMPLES              = 338;
    public static final int TIFF_SAMPLE_FORMAT              = 339;
    public static final int TIFF_S_MIN_SAMPLE_VALUE         = 340;
    public static final int TIFF_S_MAX_SAMPLE_VALUE         = 341;

    public TIFFImageDecoder(SeekableStream input,
                            ImageDecodeParam param) {
        super(input, param);
    }

    public int getNumPages() throws IOException {
        return TIFFDirectory.getNumDirectories(input);
    }

    public RenderedImage decodeAsRenderedImage(int page) throws IOException {
        if  ((page < 0) || (page >= getNumPages())) {
            throw new IOException("TIFFImageDecoder0");
        }
        return new TIFFImage(input, (TIFFDecodeParam)param, page);
    }
}