/*
 * $RCSfile: ForwWTFull.java,v $
 * $Revision: 1.1 $
 * $Date: 2005/02/11 05:02:31 $
 * $State: Exp $
 *
 * Class:                   ForwWTFull
 *
 * Description:             This class implements the full page
 *                          forward wavelet transform for both integer
 *                          and floating point implementations.
 *
 *
 *
 * COPYRIGHT:
 *
 * This software module was originally developed by Raphaël Grosbois and
 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
 * Centre France S.A) in the course of development of the JPEG2000
 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
 * software module is an implementation of a part of the JPEG 2000
 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
 * Partners) agree not to assert against ISO/IEC and users of the JPEG
 * 2000 Standard (Users) any of their rights under the copyright, not
 * including other intellectual property rights, for this software module
 * with respect to the usage by ISO/IEC and Users of this software module
 * or modifications thereof for use in hardware or software products
 * claiming conformance to the JPEG 2000 Standard. Those intending to use
 * this software module in hardware or software products are advised that
 * their use may infringe existing patents. The original developers of
 * this software module, JJ2000 Partners and ISO/IEC assume no liability
 * for use of this software module or modifications thereof. No license
 * or right to this software module is granted for non JPEG 2000 Standard
 * conforming products. JJ2000 Partners have full right to use this
 * software module for his/her own purpose, assign or donate this
 * software module to any third party and to inhibit third parties from
 * using this software module for non JPEG 2000 Standard conforming
 * products. This copyright notice must be included in all copies or
 * derivative works of this software module.
 *
 * Copyright (c) 1999/2000 JJ2000 Partners.
 * */
package jj2000.j2k.wavelet.analysis;
import java.awt.Point;

import jj2000.j2k.IntegerSpec;
import jj2000.j2k.ModuleSpec;
import jj2000.j2k.codestream.Markers;
import jj2000.j2k.entropy.CBlkSizeSpec;
import jj2000.j2k.entropy.PrecinctSizeSpec;
//import jj2000.j2k.encoder.*;
import jj2000.j2k.image.BlkImgDataSrc;
import jj2000.j2k.image.DataBlk;
import jj2000.j2k.image.DataBlkFloat;
import jj2000.j2k.image.DataBlkInt;
import jj2000.j2k.util.MathUtil;
import jj2000.j2k.wavelet.Subband;
import jj2000.j2k.wavelet.WaveletTransform;

import com.github.jaiimageio.jpeg2000.impl.J2KImageWriteParamJava;
/**
 * This class implements the ForwardWT with the full-page approach to be used
 * either with integer or floating-point filters
 * */
public class ForwWTFull extends ForwardWT {

    /** Boolean to know if one are currently dealing with int or float
        data. */
    private boolean intData;

    /**
     * The subband trees for each component, in each tile. The array is
     * allocated by the constructor of this class. This array is updated by
     * the getSubbandTree() method, an a as needed basis. The first index is
     * the tile index (in lexicographical order) and the second index is the
     * component index.
     *
     * <P>The subband tree for a component in the current tile is created on
     * the first call to getSubbandTree() for that component, in the current
     * tile. Before that the element in 'subbTrees' is null.
     * */
    private SubbandAn subbTrees[][];

    /** The source of image data */
    private BlkImgDataSrc src;

    /** The horizontal coordinate of the code-block partition origin on the
        reference grid */
    private int cb0x;

    /** The vertical coordinate of the code-block partition on the reference
        grid */
    private int cb0y;

    /** The number of decomposition levels specification */
    private IntegerSpec dls;

    /** Wavelet filters for all components and tiles */
    private AnWTFilterSpec filters;

    /** The code-block size specifications */
    private CBlkSizeSpec cblks;

    /** The precinct partition specifications */
    private PrecinctSizeSpec pss;

    /** Block storing the full band decomposition for each component. */
    private DataBlk decomposedComps[];

    /**
     * The horizontal index of the last code-block "sent" in the current
     * subband in each component. It should be -1 if none have been sent yet.
     * */
    private int lastn[];

    /**
     * The vertical index of the last code-block "sent" in the current subband
     * in each component. It should be 0 if none have been sent yet.
     * */
    private int lastm[];

    /** The subband being dealt with in each component */
    SubbandAn currentSubband[];

    /** Cache object to avoid excessive allocation/deallocation. This variable
     * makes the class inheritently thread unsafe. */
    Point ncblks;

    /**
     * Initializes this object with the given source of image data and with
     * all the decompositon parameters
     *
     * @param src From where the image data should be obtained.
     *
     * @param encSpec The encoder specifications
     *
     * @param pox The horizontal coordinate of the cell and code-block
     * partition origin with respect to the canvas origin, on the reference
     * grid.
     *
     * @param poy The vertical coordinate of the cell and code-block partition
     * origin with respect to the canvas origin, on the reference grid.
     *
     * @see ForwardWT
     * */
    public ForwWTFull(BlkImgDataSrc src,J2KImageWriteParamJava wp,int pox,int poy) {
        super(src);
        this.src  = src;

        this.cb0x  = cb0x;
        this.cb0y  = cb0y;
        this.dls  = wp.getDecompositionLevel();
        this.filters = wp.getFilters();
        this.cblks = wp.getCodeBlockSize();
        this.pss = wp.getPrecinctPartition();

        int ncomp = src.getNumComps();
        int ntiles = src.getNumTiles();

        currentSubband = new SubbandAn[ncomp];
        decomposedComps = new DataBlk[ncomp];
        subbTrees = new SubbandAn[ntiles][ncomp];
        lastn = new int[ncomp];
        lastm = new int[ncomp];
    }

    /**
     * Returns the implementation type of this wavelet transform, WT_IMPL_FULL
     * (full-page based transform). All components return the same.
     *
     * @param c The index of the component.
     *
     * @return WT_IMPL_FULL
     * */
    public int getImplementationType(int c) {
        return WaveletTransform.WT_IMPL_FULL;
    }

    /**
     * Returns the number of decomposition levels that are applied to the LL
     * band, in the specified tile-component. A value of 0 means that no
     * wavelet transform is applied.
     *
     * @param t The tile index
     *
     * @param c The index of the component.
     *
     * @return The number of decompositions applied to the LL band (0 for no
     * wavelet transform).
     * */
    public int getDecompLevels(int t,int c) {
        return ((Integer)dls.getTileCompVal(t,c)).intValue();
    }

    /**
     * Returns the wavelet tree decomposition. Actually JPEG 2000 part 1 only
     * supports WT_DECOMP_DYADIC decomposition.
     *
     * @param t The tile-index
     *
     * @param c The index of the component.
     *
     * @return The wavelet decomposition.
     * */
    public int getDecomp(int t,int c) {
        return WT_DECOMP_DYADIC;
    }

    /**
     * Returns the horizontal analysis wavelet filters used in each level, for
     * the specified component and tile. The first element in the array is the
     * filter used to obtain the lowest resolution (resolution level 0)
     * subbands (i.e. lowest frequency LL subband), the second element is the
     * one used to generate the resolution level 1 subbands, and so on. If
     * there are less elements in the array than the number of resolution
     * levels, then the last one is assumed to repeat itself.
     *
     * <P>The returned filters are applicable only to the specified component
     * and in the current tile.
     *
     * <P>The resolution level of a subband is the resolution level to which a
     * subband contributes, which is different from its decomposition level.
     *
     * @param t The index of the tile for which to return the filters.
     *
     * @param c The index of the component for which to return the filters.
     *
     * @return The horizontal analysis wavelet filters used in each level.
     * */
    public AnWTFilter[] getHorAnWaveletFilters(int t,int c) {
        return filters.getHFilters(t,c);
    }

    /**
     * Returns the vertical analysis wavelet filters used in each level, for
     * the specified component and tile. The first element in the array is the
     * filter used to obtain the lowest resolution (resolution level 0)
     * subbands (i.e. lowest frequency LL subband), the second element is the
     * one used to generate the resolution level 1 subbands, and so on. If
     * there are less elements in the array than the number of resolution
     * levels, then the last one is assumed to repeat itself.
     *
     * <P>The returned filters are applicable only to the specified component
     * and in the current tile.
     *
     * <P>The resolution level of a subband is the resolution level to which a
     * subband contributes, which is different from its decomposition level.
     *
     * @param t The index of the tile for which to return the filters.
     *
     * @param c The index of the component for which to return the filters.
     *
     * @return The vertical analysis wavelet filters used in each level.
     * */
    public AnWTFilter[] getVertAnWaveletFilters(int t,int c) {
        return filters.getVFilters(t,c);
    }

    /**
     * Returns the reversibility of the wavelet transform for the specified
     * component and tile. A wavelet transform is reversible when it is
     * suitable for lossless and lossy-to-lossless compression.
     *
     * @param t The index of the tile.
     *
     * @param c The index of the component.
     *
     * @return true is the wavelet transform is reversible, false if not.
     * */
    public boolean isReversible(int t,int c) {
        return filters.isReversible(t,c);
    }

    /**
     * Returns the horizontal offset of the code-block partition. Allowable
     * values are 0 and 1, nothing else.
     * */
    public int getCbULX() {
        return cb0x;
    }

    /**
     * Returns the vertical offset of the code-block partition. Allowable
     * values are 0 and 1, nothing else.
     * */
    public int getCbULY() {
        return cb0y;
    }

    /**
     * Returns the position of the fixed point in the specified
     * component. This is the position of the least significant integral
     * (i.e. non-fractional) bit, which is equivalent to the number of
     * fractional bits. For instance, for fixed-point values with 2 fractional
     * bits, 2 is returned. For floating-point data this value does not apply
     * and 0 should be returned. Position 0 is the position of the least
     * significant bit in the data.
     *
     * @param c The index of the component.
     *
     * @return The position of the fixed-point, which is the same as the
     * number of fractional bits. For floating-point data 0 is returned.
     * */
    public int getFixedPoint(int c) {
        return src.getFixedPoint(c);
    }


    /**
     * Returns the next code-block in the current tile for the specified
     * component. The order in which code-blocks are returned is not
     * specified. However each code-block is returned only once and all
     * code-blocks will be returned if the method is called 'N' times, where
     * 'N' is the number of code-blocks in the tile. After all the code-blocks
     * have been returned for the current tile calls to this method will
     * return 'null'.
     *
     * <p>When changing the current tile (through 'setTile()' or 'nextTile()')
     * this method will always return the first code-block, as if this method
     * was never called before for the new current tile.</p>
     *
     * <p>The data returned by this method is the data in the internal buffer
     * of this object, and thus can not be modified by the caller. The
     * 'offset' and 'scanw' of the returned data have, in general, some
     * non-zero value. The 'magbits' of the returned data is not set by this
     * method and should be ignored. See the 'CBlkWTData' class.</p>
     *
     * <p>The 'ulx' and 'uly' members of the returned 'CBlkWTData' object
     * contain the coordinates of the top-left corner of the block, with
     * respect to the tile, not the subband.</p>
     *
     * @param c The component for which to return the next code-block.
     *
     * @param cblk If non-null this object will be used to return the new
     * code-block. If null a new one will be allocated and returned.
     *
     * @return The next code-block in the current tile for component 'n', or
     * null if all code-blocks for the current tile have been returned.
     *
     * @see CBlkWTData
     * */
    public CBlkWTData getNextInternCodeBlock(int c, CBlkWTData cblk) {
        int cbm,cbn,cn,cm;
        int acb0x, acb0y;
        SubbandAn sb;
        intData = (filters.getWTDataType(tIdx,c)==DataBlk.TYPE_INT);

        //If the source image has not been decomposed 
        if(decomposedComps[c]==null) {
            int k,w,h;
            DataBlk bufblk;
            Object dst_data;

            w = getTileCompWidth(tIdx,c);
            h = getTileCompHeight(tIdx,c);

            //Get the source image data
            if(intData) {
                decomposedComps[c] = new DataBlkInt(0,0,w,h);
                bufblk = new DataBlkInt();
            } else {
                decomposedComps[c] = new DataBlkFloat(0,0,w,h);
                bufblk = new DataBlkFloat();
            }

            // Get data from source line by line (this diminishes the memory
            // requirements on the data source)
            dst_data = decomposedComps[c].getData();
            int lstart = getCompULX(c);
            bufblk.ulx = lstart;
            bufblk.w = w;
            bufblk.h = 1;
            int kk = getCompULY(c);
            for (k=0; k<h; k++,kk++) {
                bufblk.uly = kk;
                bufblk.ulx = lstart;
                bufblk = src.getInternCompData(bufblk,c);
                System.arraycopy(bufblk.getData(),bufblk.offset,
                                 dst_data,k*w,w);
            }

            //Decompose source image
            waveletTreeDecomposition(decomposedComps[c],
                                     getAnSubbandTree(tIdx,c),c);

            // Make the first subband the current one
            currentSubband[c] = getNextSubband(c);

            lastn[c] = -1;
            lastm[c] = 0;
        }

        // Get the next code-block to "send"
        do {
            // Calculate number of code-blocks in current subband
            ncblks = currentSubband[c].numCb;
            // Goto next code-block
            lastn[c]++;
            if (lastn[c] == ncblks.x) { // Got to end of this row of
                // code-blocks
                lastn[c] = 0;
                lastm[c]++;
            }
            if (lastm[c] < ncblks.y) {
                // Not past the last code-block in the subband, we can return
                // this code-block
                break;
            }
            // If we get here we already sent all code-blocks in this subband,
            // goto next subband
            currentSubband[c] = getNextSubband(c);
            lastn[c] = -1;
            lastm[c] = 0;
            if ( currentSubband[c] == null ) {
                // We don't need the transformed data any more (a priori)
                decomposedComps[c] = null;
                // All code-blocks from all subbands in the current
                // tile have been returned so we return a null
                // reference
                return null;
            }
            // Loop to find the next code-block
        } while (true);


        // Project code-block partition origin to subband. Since the origin is
        // always 0 or 1, it projects to the low-pass side (throught the ceil
        // operator) as itself (i.e. no change) and to the high-pass side
        // (through the floor operator) as 0, always.
        acb0x = cb0x;
        acb0y = cb0y;
        switch (currentSubband[c].sbandIdx) {
        case Subband.WT_ORIENT_LL:
            // No need to project since all low-pass => nothing to do
            break;
        case Subband.WT_ORIENT_HL:
            acb0x = 0;
            break;
        case Subband.WT_ORIENT_LH:
            acb0y = 0;
            break;
        case Subband.WT_ORIENT_HH:
            acb0x = 0;
            acb0y = 0;
            break;
        default:
            throw new Error("Internal JJ2000 error");
        }
        // Initialize output code-block
        if (cblk==null) {
            if (intData) {
                cblk = new CBlkWTDataInt();
            } else {
                cblk = new CBlkWTDataFloat();
            }
        }
        cbn = lastn[c];
        cbm = lastm[c];
        sb = currentSubband[c];
        cblk.n = cbn;
        cblk.m = cbm;
        cblk.sb = sb;
        // Calculate the indexes of first code-block in subband with respect
        // to the partitioning origin, to then calculate the position and size
        // NOTE: when calculating "floor()" by integer division the dividend
        // and divisor must be positive, we ensure that by adding the divisor
        // to the dividend and then substracting 1 to the result of the
        // division
        cn = (sb.ulcx-acb0x+sb.nomCBlkW)/sb.nomCBlkW-1;
        cm = (sb.ulcy-acb0y+sb.nomCBlkH)/sb.nomCBlkH-1;
        if (cbn == 0) { // Left-most code-block, starts where subband starts
            cblk.ulx = sb.ulx;
        } else {
            // Calculate starting canvas coordinate and convert to subb. coords
            cblk.ulx = (cn+cbn)*sb.nomCBlkW - (sb.ulcx-acb0x) + sb.ulx;
        }
        if (cbm == 0) { // Bottom-most code-block, starts where subband starts
            cblk.uly = sb.uly;
        } else {
            cblk.uly = (cm+cbm)*sb.nomCBlkH - (sb.ulcy-acb0y) + sb.uly;
        }
        if (cbn < ncblks.x-1) {
            // Calculate where next code-block starts => width
            cblk.w = (cn+cbn+1)*sb.nomCBlkW - (sb.ulcx-acb0x) + sb.ulx -
                cblk.ulx;
        } else { // Right-most code-block, ends where subband ends
            cblk.w = sb.ulx+sb.w-cblk.ulx;
        }
        if (cbm < ncblks.y-1) {
            // Calculate where next code-block starts => height
            cblk.h = (cm+cbm+1)*sb.nomCBlkH - (sb.ulcy-acb0y) + sb.uly -
                cblk.uly;
        } else { // Bottom-most code-block, ends where subband ends
            cblk.h = sb.uly+sb.h-cblk.uly;
        }
        cblk.wmseScaling = 1f;

        // Since we are in getNextInternCodeBlock() we can return a
        // reference to the internal buffer, no need to copy. Just initialize
        // the 'offset' and 'scanw'
        cblk.offset = cblk.uly*decomposedComps[c].w+cblk.ulx;
        cblk.scanw = decomposedComps[c].w;

        // For the data just put a reference to our buffer
        cblk.setData(decomposedComps[c].getData());
        // Return code-block
        return cblk;
    }

    /**
     * Returns the next code-block in the current tile for the specified
     * component, as a copy (see below). The order in which code-blocks are
     * returned is not specified. However each code-block is returned only
     * once and all code-blocks will be returned if the method is called 'N'
     * times, where 'N' is the number of code-blocks in the tile. After all
     * the code-blocks have been returned for the current tile calls to this
     * method will return 'null'.
     *
     * <P>When changing the current tile (through 'setTile()' or 'nextTile()')
     * this method will always return the first code-block, as if this method
     * was never called before for the new current tile.
     *
     * <P>The data returned by this method is always a copy of the internal
     * data of this object, and it can be modified "in place" without
     * any problems after being returned. The 'offset' of the returned data is
     * 0, and the 'scanw' is the same as the code-block width.  The 'magbits'
     * of the returned data is not set by this method and should be
     * ignored. See the 'CBlkWTData' class.
     *
     * <P>The 'ulx' and 'uly' members of the returned 'CBlkWTData' object
     * contain the coordinates of the top-left corner of the block, with
     * respect to the tile, not the subband.
     *
     * @param c The component for which to return the next code-block.
     *
     * @param cblk If non-null this object will be used to return the new
     * code-block. If null a new one will be allocated and returned. If the
     * "data" array of the object is non-null it will be reused, if possible,
     * to return the data.
     *
     * @return The next code-block in the current tile for component 'c', or
     * null if all code-blocks for the current tile have been returned.
     *
     * @see CBlkWTData
     * */
    public CBlkWTData getNextCodeBlock(int c, CBlkWTData cblk) {
        // We can not directly use getNextInternCodeBlock() since that returns
        // a reference to the internal buffer, we have to copy that data

        int j,k;
        int w;
        Object dst_data; // a int[] or float[] object
        int[] dst_data_int;
        float[] dst_data_float;
        Object src_data; // a int[] or float[] object

        intData = (filters.getWTDataType(tIdx,c)==DataBlk.TYPE_INT);

        dst_data = null;

        // Cache the data array, if any
        if (cblk != null) {
            dst_data = cblk.getData();
        }

        // Get the next code-block
        cblk = getNextInternCodeBlock(c,cblk);

        if (cblk == null) {
            return null; // No more code-blocks in current tile for component
            // c
        }

        // Ensure size of output buffer
        if (intData) { // int data
            dst_data_int = (int[]) dst_data;
            if (dst_data_int == null || dst_data_int.length < cblk.w*cblk.h) {
                dst_data = new int[cblk.w*cblk.h];
            }
        }
        else { // float data
            dst_data_float = (float[]) dst_data;
            if (dst_data_float == null ||
                dst_data_float.length < cblk.w*cblk.h) {
                dst_data = new float[cblk.w*cblk.h];
            }
        }

        // Copy data line by line
        src_data = cblk.getData();
        w = cblk.w;
        for (j = w*(cblk.h-1), k = cblk.offset+(cblk.h-1)*cblk.scanw;
             j >= 0; j -= w, k -= cblk.scanw) {
            System.arraycopy(src_data,k,dst_data,j,w);
        }
        cblk.setData(dst_data);
        cblk.offset = 0;
        cblk.scanw = w;

        return cblk;
    }

    /**
     * Return the data type of this CBlkWTDataSrc. Its value should be either
     * DataBlk.TYPE_INT or DataBlk.TYPE_FLOAT but can change according to the
     * current tile-component.
     *
     * @param t The index of the tile for which to return the data type.
     *
     * @param c The index of the component for which to return the data type.
     *
     * @return Current data type
     * */
    public int getDataType(int t,int c){
        return filters.getWTDataType(t,c);
    }

    /**
     * Returns the next subband that will be used to get the next code-block
     * to return by the getNext[Intern]CodeBlock method.
     *
     * @param c The component
     *
     * @return Its returns the next subband that will be used to get the next
     * code-block to return by the getNext[Intern]CodeBlock method.
     **/
    private SubbandAn getNextSubband(int c) {
        int down = 1;
        int up = 0;
        int direction = down;
        SubbandAn nextsb;

        nextsb = currentSubband[c];
        //If it is the first call to this method
        if(nextsb == null) {
            nextsb = this.getAnSubbandTree(tIdx,c);
            //If there is no decomposition level then send the whole image
            if(!nextsb.isNode) {
                return nextsb;
            }
        }

        //Find the next subband to send
        do {
            //If the current subband is null then break
            if(nextsb == null) {
                break;
            }

            //If the current subband is a leaf then select the next leaf to
            //send or go up in the decomposition tree if the leaf was a LL
            //one.
            else if(!nextsb.isNode) {
                switch (nextsb.orientation) {
                    case Subband.WT_ORIENT_HH :
                        nextsb = (SubbandAn)nextsb.getParent().getLH();
                        direction = down;
                        break;
                    case Subband.WT_ORIENT_LH :
                        nextsb = (SubbandAn)nextsb.getParent().getHL();
                        direction = down;
                        break;
                    case Subband.WT_ORIENT_HL :
                        nextsb = (SubbandAn)nextsb.getParent().getLL();
                        direction = down;
                        break;
                    case Subband.WT_ORIENT_LL :
                        nextsb = (SubbandAn)nextsb.getParent();
                        direction = up;
                        break;
                }
            }

            //Else if the current subband is a node
            else if(nextsb.isNode) {
                //If the direction is down the select the HH subband of the
                //current node.
                if(direction == down) {
                    nextsb = (SubbandAn)nextsb.getHH();
                }
                //Else the direction is up the select the next node to cover
                //or still go up in the decomposition tree if the node is a LL
                //subband
                else if(direction == up) {
                    switch (nextsb.orientation) {
                        case Subband.WT_ORIENT_HH :
                            nextsb = (SubbandAn)nextsb.getParent().getLH();
                            direction = down;
                            break;
                        case Subband.WT_ORIENT_LH :
                            nextsb = (SubbandAn)nextsb.getParent().getHL();
                            direction = down;
                            break;
                        case Subband.WT_ORIENT_HL :
                            nextsb = (SubbandAn)nextsb.getParent().getLL();
                            direction = down;
                            break;
                        case Subband.WT_ORIENT_LL :
                            nextsb = (SubbandAn)nextsb.getParent();
                            direction = up;
                            break;
                    }
                }
            }

            if(nextsb == null) {
                break;
            }
        } while(nextsb.isNode);
        return nextsb;
    }

    /**
     * Performs the forward wavelet transform on the whole band. It
     * iteratively decomposes the subbands from the top node to the leaves.
     *
     * @param band The band containing the float data to decompose
     *
     * @param subband The structure containing the coordinates of the current
     * subband in the whole band to decompose.
     *
     * @param c The index of the current component to decompose
     * */
    private void waveletTreeDecomposition(DataBlk band,
                                          SubbandAn subband, int c) {

        //If the current subband is a leaf then nothing to be done (a leaf is
        //not decomposed).
        if(!subband.isNode)
            return;

        else {
            //Perform the 2D wavelet decomposition of the current subband
            wavelet2DDecomposition(band, (SubbandAn)subband, c);

            //Perform the decomposition of the four resulting subbands
            waveletTreeDecomposition(band, (SubbandAn)subband.getHH(), c);
            waveletTreeDecomposition(band, (SubbandAn)subband.getLH(), c);
            waveletTreeDecomposition(band, (SubbandAn)subband.getHL(), c);
            waveletTreeDecomposition(band, (SubbandAn)subband.getLL(), c);
        }
    }

    /**
     * Performs the 2D forward wavelet transform on a subband of the initial
     * band. This method will successively perform 1D filtering steps on all
     * lines and then all columns of the subband. In this class only filters
     * with floating point implementations can be used.
     *
     * @param band The band containing the float data to decompose
     *
     * @param subband The structure containing the coordinates of the subband
     * in the whole band to decompose.
     *
     * @param c The index of the current component to decompose
     * */
    private void wavelet2DDecomposition(DataBlk band,
        SubbandAn subband, int c) {

        int ulx, uly, w, h;
        int band_w, band_h;

        // If subband is empty (i.e. zero size) nothing to do
        if (subband.w == 0 || subband.h == 0) {
            return;
        }

        ulx = subband.ulx;
        uly = subband.uly;
        w = subband.w;
        h = subband.h;
        band_w = getTileCompWidth(tIdx, c);
        band_h = getTileCompHeight(tIdx, c);

        if ( intData ) {
            //Perform the decompositions if the filter is implemented with an
            //integer arithmetic.
            int i, j;
            int offset;
            int[] tmpVector = new int[java.lang.Math.max(w,h)];

            int[] data = ((DataBlkInt)band).getDataInt();

            //Perform the vertical decomposition
            if (subband.ulcy%2==0) { // Even start index => use LPF
                for(j=0; j<w; j++) {
                    offset = uly*band_w + ulx+j;
                    for(i=0; i<h; i++)
                        tmpVector[i] = data[offset+(i*band_w)];
                    subband.vFilter.analyze_lpf(tmpVector, 0, h, 1,
                                             data, offset, band_w,
                                             data, offset+((h+1)/2)*band_w,
                                             band_w);
                }
            }
            else { // Odd start index => use HPF
                for(j=0; j<w; j++) {
                    offset = uly*band_w + ulx+j;
                    for(i=0; i<h; i++)
                        tmpVector[i] = data[offset+(i*band_w)];
                    subband.vFilter.analyze_hpf(tmpVector, 0, h, 1,
                                             data, offset, band_w,
                                             data, offset+(h/2)*band_w,
                                             band_w);
                }
            }

            //Perform the horizontal decomposition.
            if (subband.ulcx%2==0) { // Even start index => use LPF
                for(i=0; i<h; i++) {
                    offset = (uly+i)*band_w + ulx;
                    for(j=0; j<w; j++)
                        tmpVector[j] = data[offset+j];
                    subband.hFilter.analyze_lpf(tmpVector, 0, w, 1,
                                             data, offset, 1,
                                             data, offset+(w+1)/2, 1);
                }
            }
            else { // Odd start index => use HPF
                for(i=0; i<h; i++) {
                    offset = (uly+i)*band_w + ulx;
                    for(j=0; j<w; j++)
                        tmpVector[j] = data[offset+j];
                    subband.hFilter.analyze_hpf(tmpVector, 0, w, 1,
                                             data, offset, 1,
                                             data, offset+w/2, 1);
                }
            }
        }
        else {
            //Perform the decompositions if the filter is implemented with a
            //float arithmetic.
            int i, j;
            int offset;
            float[] tmpVector = new float[java.lang.Math.max(w,h)];
            float[]data = ((DataBlkFloat)band).getDataFloat();

            //Perform the vertical decomposition.
            if (subband.ulcy%2==0) { // Even start index => use LPF
                for(j=0; j<w; j++) {
                    offset = uly*band_w + ulx+j;
                    for(i=0; i<h; i++)
                        tmpVector[i] = data[offset+(i*band_w)];
                    subband.vFilter.analyze_lpf(tmpVector, 0, h, 1,
                                             data, offset, band_w,
                                             data, offset+((h+1)/2)*band_w,
                                             band_w);
                }
            }
            else { // Odd start index => use HPF
                for(j=0; j<w; j++) {
                    offset = uly*band_w + ulx+j;
                    for(i=0; i<h; i++)
                        tmpVector[i] = data[offset+(i*band_w)];
                    subband.vFilter.analyze_hpf(tmpVector, 0, h, 1,
                                             data, offset, band_w,
                                             data, offset+(h/2)*band_w,
                                             band_w);
                }
            }
            //Perform the horizontal decomposition.
            if (subband.ulcx%2==0) { // Even start index => use LPF
                for(i=0; i<h; i++) {
                    offset = (uly+i)*band_w + ulx;
                    for(j=0; j<w; j++)
                        tmpVector[j] = data[offset+j];
                    subband.hFilter.analyze_lpf(tmpVector, 0, w, 1,
                                             data, offset, 1,
                                             data, offset+(w+1)/2, 1);
                }
            }
            else { // Odd start index => use HPF
                for(i=0; i<h; i++) {
                    offset = (uly+i)*band_w + ulx;
                    for(j=0; j<w; j++)
                        tmpVector[j] = data[offset+j];
                    subband.hFilter.analyze_hpf(tmpVector, 0, w, 1,
                                             data, offset, 1,
                                             data, offset+w/2, 1);
                }
            }
        }
    }

    /**
     * Changes the current tile, given the new coordinates.
     *
     * <P>This method resets the 'subbTrees' array, and recalculates the
     * values of the 'reversible' array. It also resets the decomposed
     * component buffers.
     *
     * @param x The horizontal coordinate of the tile.
     *
     * @param y The vertical coordinate of the new tile.
     * */
    public void setTile(int x, int y) {
        int i;

        // Change tile
        super.setTile(x,y);

        // Reset the decomposed component buffers.
        if (decomposedComps != null) {
            for (i=decomposedComps.length-1; i>=0; i--) {
                decomposedComps[i] = null;
                currentSubband[i] = null;
            }
        }

    }

    /**
     * Advances to the next tile, in standard scan-line order (by rows then
     * columns). An NoNextElementException is thrown if the current tile is
     * the last one (i.e. there is no next tile).
     *
     * <P>This method resets the 'subbTrees' array, and recalculates the
     * values of the 'reversible' array. It also resets the decomposed
     * component buffers.
     * */
    public void nextTile() {
        int i;

        // Change tile
        super.nextTile();
        // Reset the decomposed component buffers
        if (decomposedComps != null) {
            for (i=decomposedComps.length-1; i>=0; i--) {
                decomposedComps[i] = null;
                currentSubband[i] = null;
            }
        }

    }

    /**
     * Returns a reference to the subband tree structure representing the
     * subband decomposition for the specified tile-component of the source.
     *
     * @param t The index of the tile.
     *
     * @param c The index of the component.
     *
     * @return The subband tree structure, see Subband.
     *
     * @see SubbandAn
     * @see Subband
     * */
    public SubbandAn getAnSubbandTree(int t,int c) {
        if (subbTrees[t][c] == null) {
            subbTrees[t][c] =
                new SubbandAn(getTileCompWidth(tIdx, c),getTileCompHeight(tIdx, c),
                              getCompULX(c),getCompULY(c),
                              getDecompLevels(t,c),
                              getHorAnWaveletFilters(t,c),
                              getVertAnWaveletFilters(t,c));
            initSubbandsFields(t,c,subbTrees[t][c]);
        }
        return subbTrees[t][c];
    }

    /** 
     * Initialises subbands fields, such as number of code-blocks and
     * code-blocks dimension, in the subband tree. The nominal code-block
     * width/height depends on the precincts dimensions if used.
     *
     * @param t The tile index of the subband
     *
     * @param c The component index
     *
     * @param sb The subband tree to be initialised.
     * */
    private void initSubbandsFields(int t,int c,Subband sb) {
        int cbw = cblks.getCBlkWidth(ModuleSpec.SPEC_TILE_COMP,t,c);
        int cbh = cblks.getCBlkHeight(ModuleSpec.SPEC_TILE_COMP,t,c);

        if (!sb.isNode) {
            // Code-blocks dimension
            int ppx, ppy;
            int ppxExp, ppyExp, cbwExp, cbhExp;
            ppx = pss.getPPX(t,c,sb.resLvl);
            ppy = pss.getPPY(t,c,sb.resLvl);

            if (ppx!=Markers.PRECINCT_PARTITION_DEF_SIZE
                 || ppy!=Markers.PRECINCT_PARTITION_DEF_SIZE ) {

                ppxExp = MathUtil.log2(ppx);
                ppyExp = MathUtil.log2(ppy);
                cbwExp = MathUtil.log2(cbw);
                cbhExp = MathUtil.log2(cbh);

                // Precinct partition is used
                switch (sb.resLvl) {
                    case 0:
                        sb.nomCBlkW = ( cbwExp<ppxExp ?
                            (1<<cbwExp) : (1<<ppxExp) );
                        sb.nomCBlkH = ( cbhExp<ppyExp ?
                            (1<<cbhExp) : (1<<ppyExp) );
                        break;

                    default:
                        sb.nomCBlkW = ( cbwExp<ppxExp-1 ?
                            (1<<cbwExp) : (1<<(ppxExp-1)) );
                        sb.nomCBlkH = ( cbhExp<ppyExp-1 ?
                            (1<<cbhExp) : (1<<(ppyExp-1)) );
                        break;
                }
            } else {
                sb.nomCBlkW = cbw;
                sb.nomCBlkH = cbh;
            }

            // Number of code-blocks
            if(sb.numCb==null) sb.numCb = new Point();
            if(sb.w!=0 && sb.h!=0) {
                int acb0x = cb0x;
                int acb0y = cb0y;
                int tmp;

                // Project code-block partition origin to subband. Since the
                // origin is always 0 or 1, it projects to the low-pass side
                // (throught the ceil operator) as itself (i.e. no change) and
                // to the high-pass side (through the floor operator) as 0,
                // always.
                switch (sb.sbandIdx) {
                case Subband.WT_ORIENT_LL:
                    // No need to project since all low-pass => nothing to do
                    break;
                case Subband.WT_ORIENT_HL:
                    acb0x = 0;
                    break;
                case Subband.WT_ORIENT_LH:
                    acb0y = 0;
                    break;
                case Subband.WT_ORIENT_HH:
                    acb0x = 0;
                    acb0y = 0;
                    break;
                default:
                    throw new Error("Internal JJ2000 error");
                }
                if(sb.ulcx-acb0x<0 || sb.ulcy-acb0y<0) {
                    throw new IllegalArgumentException("Invalid code-blocks "+
                                                       "partition origin or "+
                                                       "image offset in the "+
                                                       "reference grid.");
                }
                // NOTE: when calculating "floor()" by integer division the
                // dividend and divisor must be positive, we ensure that by
                // adding the divisor to the dividend and then substracting 1
                // to the result of the division
                tmp = sb.ulcx-acb0x+sb.nomCBlkW;
                sb.numCb.x = (tmp+sb.w-1)/sb.nomCBlkW - (tmp/sb.nomCBlkW-1);
                tmp = sb.ulcy-acb0y+sb.nomCBlkH;
                sb.numCb.y = (tmp+sb.h-1)/sb.nomCBlkH - (tmp/sb.nomCBlkH-1);
            } else {
                sb.numCb.x = sb.numCb.y = 0;
            }
        } else {
            initSubbandsFields(t,c,sb.getLL());
            initSubbandsFields(t,c,sb.getHL());
            initSubbandsFields(t,c,sb.getLH());
            initSubbandsFields(t,c,sb.getHH());
        }
    }

}