/*
 * $RCSfile: InvCompTransf.java,v $
 * $Revision: 1.1 $
 * $Date: 2005/02/11 05:02:14 $
 * $State: Exp $
 *
 * Class:               InvCompTransf
 *
 * Description:         Inverse Component transformations applied to tiles
 *
 *
 *
 * 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.image.invcomptransf;

import jj2000.j2k.ModuleSpec;
import jj2000.j2k.decoder.DecoderSpecs;
import jj2000.j2k.image.BlkImgDataSrc;
import jj2000.j2k.image.CompTransfSpec;
import jj2000.j2k.image.DataBlk;
import jj2000.j2k.image.DataBlkFloat;
import jj2000.j2k.image.DataBlkInt;
import jj2000.j2k.image.ImgDataAdapter;
import jj2000.j2k.util.MathUtil;
import jj2000.j2k.wavelet.synthesis.SynWTFilterSpec;

/**
 * This class apply inverse component transformations to the tiles depending
 * on specification read from the codestream header. These transformations can
 * be used to improve compression efficiency but are not related to colour
 * transforms used to map colour values for display purposes. JPEG 2000 part I
 * defines 2 component transformations: RCT (Reversible Component
 * Transformation) and ICT (Irreversible Component Transformation).
 *
 * @see ModuleSpec
 * */
public class InvCompTransf extends ImgDataAdapter
    implements BlkImgDataSrc{

    /** Identifier for no component transformation. Value is 0. */
    public static final int NONE = 0;

    /** The prefix for inverse component transformation options: 'M' */
    public final static char OPT_PREFIX = 'M';

    /** The list of parameters that is accepted by the inverse
     * component transformation module. They start with 'M'. */
    private final static String [][] pinfo = null;

    /** Identifier for the Inverse Reversible Component Transformation
        (INV_RCT). Value is 1. */
    public static final int INV_RCT = 1;

    /** Identifier for the Inverse Irreversible Component
        Transformation (INV_ICT). Value is 2 */
    public static final int INV_ICT = 2;

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

    /** The component transformations specifications */
    private CompTransfSpec cts;

    /** The wavelet filter specifications */
    private SynWTFilterSpec wfs;

    /** The type of the current component transformation JPEG 2000
     * part I only support NONE, FORW_RCT and FORW_ICT types*/
    private int transfType = NONE;

    /** Buffer for each component of output data */
    private int[][] outdata = new int[3][];

    /** Block used to request component 0 */
    private DataBlk block0;

    /** Block used to request component 1 */
    private DataBlk block1;

    /** Block used to request component 2 */
    private DataBlk block2;

    /** Data block used only to store coordinates and progressiveness
        of the buffered blocks */
    private DataBlkInt dbi = new DataBlkInt();

    /** The bit-depths of un-transformed components */
    private int utdepth[];

    /** Flag indicating whether the decoder should skip the component 
     * transform*/
    private boolean noCompTransf = false;

    /**
     * Constructs a new ForwCompTransf object that operates on the
     * specified source of image data.
     *
     * @param imgSrc The source from where to get the data to be
     * transformed
     *
     * @param decSpec The decoder specifications
     *
     * @see BlkImgDataSrc
     * */
    public InvCompTransf(BlkImgDataSrc imgSrc, DecoderSpecs decSpec,
                         int[] utdepth) {
        super(imgSrc);
        this.cts = decSpec.cts;
        this.wfs = decSpec.wfs;
        src = imgSrc;
        this.utdepth = utdepth;
    }

    /**
     * Returns the parameters that are used in this class and implementing
     * classes. It returns a 2D String array. Each of the 1D arrays is for a
     * different option, and they have 4 elements. The first element is the
     * option name, the second one is the synopsis, the third one is a long
     * description of what the parameter is and the fourth is its default
     * value. The synopsis or description may be 'null', in which case it is
     * assumed that there is no synopsis or description of the option,
     * respectively. Null may be returned if no options are supported.
     *
     * @return the options name, their synopsis and their explanation,
     * or null if no options are supported.
     * */
    public static String[][] getParameterInfo() {
        return pinfo;
    }

    /**
     * Returns a string with a descriptive text of which inverse component
     * transformation is used. This can be either "Inverse RCT" or "Inverse
     * ICT" or "No component transformation" depending on the current tile.
     *
     * @return A descriptive string
     * */
    public String toString() {
        switch(transfType){
        case INV_RCT:
            return "Inverse RCT";
        case INV_ICT:
            return "Inverse ICT";
        case NONE:
            return "No component transformation";
        default:
            throw new IllegalArgumentException("Non JPEG 2000 part I"+
                                               " component transformation");
        }
    }

    /**
     * Returns true if this transform is reversible in current
     * tile. Reversible component transformations are those which operation
     * can be completely reversed without any loss of information (not even
     * due to rounding).
     *
     * @return Reversibility of component transformation in current
     * tile
     * */
    public boolean isReversible(){
        switch(transfType){
        case NONE:
        case INV_RCT:
            return true;
        case INV_ICT:
            return false;
        default:
            throw new IllegalArgumentException("Non JPEG 2000 part I"+
                                               " component transformation");
        }
    }

    /**
     * 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.
     *
     * <P>This default implementation assumes that the number of fractional
     * bits is not modified by the component mixer.
     *
     * @param c The index of the component.
     *
     * @return The value of the fixed point position of the source since the
     * color transform does not affect it.
     * */
     public int getFixedPoint(int c) {
         return src.getFixedPoint(c);
     }

    /**
     * Calculates the bitdepths of the transformed components, given the
     * bitdepth of the un-transformed components and the component
     * tranformation type.
     *
     * @param utdepth The bitdepth of each un-transformed component
     *
     * @param ttype The type ID of the inverse component tranformation
     *
     * @param tdepth If not null the results are stored in this
     * array, otherwise a new array is allocated and returned.
     *
     * @return The bitdepth of each transformed component.
     * */
    public static
        int[] calcMixedBitDepths(int utdepth[], int ttype, int tdepth[]) {

        if (utdepth.length < 3 && ttype != NONE) {
            throw new IllegalArgumentException();
        }

        if (tdepth == null) {
            tdepth = new int[utdepth.length];
        }

        switch (ttype) {
        case NONE:
            System.arraycopy(utdepth,0,tdepth,0,utdepth.length);
            break;
        case INV_RCT:
            if (utdepth.length >3) {
                System.arraycopy(utdepth,3,tdepth,3,utdepth.length-3);
            }
            // The formulas are:
            // tdepth[0] = ceil(log2(2^(utdepth[0])+2^utdepth[1]+
            //                        2^(utdepth[2])))-2+1
            // tdepth[1] = ceil(log2(2^(utdepth[0])+2^(utdepth[1])-1))+1
            // tdepth[2] = ceil(log2(2^(utdepth[1])+2^(utdepth[2])-1))+1
            // The MathUtil.log2(x) function calculates floor(log2(x)), so we
            // use 'MathUtil.log2(2*x-1)+1', which calculates ceil(log2(x))
            // for any x>=1, x integer.
            tdepth[0] = MathUtil.log2((1<<utdepth[0])+(2<<utdepth[1])+
                                      (1<<utdepth[2])-1)-2+1;
            tdepth[1] = MathUtil.log2((1<<utdepth[2])+(1<<utdepth[1])-1)+1;
            tdepth[2] = MathUtil.log2((1<<utdepth[0])+(1<<utdepth[1])-1)+1;
            break;
        case INV_ICT:
            if (utdepth.length >3) {
                System.arraycopy(utdepth,3,tdepth,3,utdepth.length-3);
            }
            // The MathUtil.log2(x) function calculates floor(log2(x)), so we
            // use 'MathUtil.log2(2*x-1)+1', which calculates ceil(log2(x))
            // for any x>=1, x integer.
            tdepth[0] =
                MathUtil.log2((int)Math.floor((1<<utdepth[0])*0.299072+
                                              (1<<utdepth[1])*0.586914+
                                              (1<<utdepth[2])*0.114014)-1)+1;
            tdepth[1] =
                MathUtil.log2((int)Math.floor((1<<utdepth[0])*0.168701+
                                              (1<<utdepth[1])*0.331299+
                                              (1<<utdepth[2])*0.5)-1)+1;
            tdepth[2] =
                MathUtil.log2((int)Math.floor((1<<utdepth[0])*0.5+
                                              (1<<utdepth[1])*0.418701+
                                              (1<<utdepth[2])*0.081299)-1)+1;
            break;
        }

        return tdepth;
    }

    /**
     * Returns the number of bits, referred to as the "range bits",
     * corresponding to the nominal range of the data in the specified
     * component. If this number is <i>b</b> then for unsigned data the
     * nominal range is between 0 and 2^b-1, and for signed data it is between
     * -2^(b-1) and 2^(b-1)-1.
     *
     * @param c The index of the component.
     *
     * @return The bitdepth of un-transformed component 'c'.
     * */
    public int getNomRangeBits(int c) {
        return utdepth[c];
    }

    /**
     * Apply inverse component transformation associated with the current
     * tile. If no component transformation has been requested by the user,
     * data are not modified.
     *
     * <P>This method calls the getInternCompData() method, but respects the
     * definitions of the getCompData() method defined in the BlkImgDataSrc
     * interface.
     *
     * @param blk Determines the rectangular area to return, and the
     * data is returned in this object.
     *
     * @param c Index of the output component.
     *
     * @return The requested DataBlk
     *
     * @see BlkImgDataSrc#getCompData
     * */
    public DataBlk getCompData(DataBlk blk, int c){
        // If requesting a component whose index is greater than 3 or there is
        // no transform return a copy of data (getInternCompData returns the
        // actual data in those cases)
        if (c>=3 || transfType == NONE) {
            return src.getCompData(blk,c);
        }
        else { // We can use getInternCompData (since data is a copy anyways)
            return getInternCompData(blk,c);
        }
    }

    /**
     * Apply the inverse component transformation associated with the current
     * tile. If no component transformation has been requested by the user,
     * data are not modified. Else, appropriate method is called (invRCT or
     * invICT).
     *
     * @see #invRCT
     *
     * @see #invICT
     *
     * @param blk Determines the rectangular area to return.
     *
     * @param c Index of the output component.
     *
     * @return The requested DataBlk
     * */
    public DataBlk getInternCompData(DataBlk blk, int c){
        // if specified in the command line that no component transform should
        // be made, return original data
        if(noCompTransf)
            return src.getInternCompData(blk,c);

        switch(transfType){
        case NONE:
            return src.getInternCompData(blk,c);
        case INV_RCT:
            return invRCT(blk,c);
        case INV_ICT:
            return invICT(blk,c);
        default:
            throw new IllegalArgumentException("Non JPEG 2000 part I"+
                                               " component transformation");
        }
    }

    /**
     * Apply inverse component transformation to obtain requested component
     * from specified block of data. Whatever the type of requested DataBlk,
     * it always returns a DataBlkInt.
     *
     * @param blk Determine the rectangular area to return
     *
     * @param c The index of the requested component
     *
     * @return Data of requested component
     * */
    private DataBlk invRCT(DataBlk blk,int c){
        // If the component number is three or greater, return original data
        if (c>=3 && c < getNumComps()) {
            // Requesting a component whose index is greater than 3
            return src.getInternCompData(blk,c);
        }

        // If asking a component for the first time for this block,
        // do transform for the 3 components
        if ((outdata[c] == null)||
            (dbi.ulx > blk.ulx) || (dbi.uly > blk.uly) ||
            (dbi.ulx+dbi.w < blk.ulx+blk.w) ||
            (dbi.uly+dbi.h < blk.uly+blk.h)) {
            int k,k0,k1,k2,mink,i;
            int w = blk.w; //width of output block
            int h = blk.h; //height of ouput block

            //Reference to output block data array
            outdata[c] = (int[]) blk.getData();

            //Create data array of blk if necessary
            if(outdata[c] == null || outdata[c].length!=h*w){
                outdata[c] = new int[h * w];
                blk.setData(outdata[c]);
            }

            outdata[(c+1)%3] = new int[outdata[c].length];
            outdata[(c+2)%3] = new int[outdata[c].length];

            if(block0==null || block0.getDataType()!=DataBlk.TYPE_INT)
                block0 = new DataBlkInt();
            if(block1==null || block1.getDataType()!=DataBlk.TYPE_INT)
                block1 = new DataBlkInt();
            if(block2==null || block2.getDataType()!=DataBlk.TYPE_INT)
                block2 = new DataBlkInt();
            block0.w = block1.w = block2.w = blk.w;
            block0.h = block1.h = block2.h = blk.h;
            block0.ulx = block1.ulx = block2.ulx = blk.ulx;
            block0.uly = block1.uly = block2.uly = blk.uly;

            int data0[],data1[],data2[]; // input data arrays

            // Fill in buffer blocks (to be read only)
            // Returned blocks may have different size and position
            block0 = (DataBlkInt)src.getInternCompData(block0, 0);
            data0 = (int[]) block0.getData();
            block1 = (DataBlkInt)src.getInternCompData(block1, 1);
            data1 = (int[]) block1.getData();
            block2 = (DataBlkInt)src.getInternCompData(block2, 2);
            data2 = (int[]) block2.getData();

            // Set the progressiveness of the output data
            blk.progressive = block0.progressive || block1.progressive ||
                block2.progressive;
            blk.offset = 0;
            blk.scanw = w;

            // set attributes of the DataBlk used for buffering
            dbi.progressive = blk.progressive;
            dbi.ulx = blk.ulx;
            dbi.uly = blk.uly;
            dbi.w = blk.w;
            dbi.h = blk.h;

            // Perform conversion

            // Initialize general indexes
            k = w*h-1;
            k0 = block0.offset+(h-1)*block0.scanw+w-1;
            k1 = block1.offset+(h-1)*block1.scanw+w-1;
            k2 = block2.offset+(h-1)*block2.scanw+w-1;

            for( i = h-1; i >=0; i--){
                for(mink = k-w; k > mink; k--, k0--, k1--, k2--){
                    outdata[1][k] = (data0[k0] - ((data1[k1]+data2[k2])>>2) );
                    outdata[0][k] = data2[k2] + outdata[1][k];
                    outdata[2][k] = data1[k1] + outdata[1][k];
                }
                // Jump to beggining of previous line in input
                k0 -= block0.scanw - w;
                k1 -= block1.scanw - w;
                k2 -= block2.scanw - w;
            }
            outdata[c] = null;
        }
        else if((c>=0)&&(c<=3)){ //Asking for the 2nd or 3rd block component
            blk.setData(outdata[c]);
            blk.progressive = dbi.progressive;
            blk.offset = (blk.uly-dbi.uly)*dbi.w+blk.ulx-dbi.ulx;
            blk.scanw = dbi.w;
            outdata[c] = null;
        }
        else {
            // Requesting a non valid component index
            throw new IllegalArgumentException();
        }
        return blk;
    }

    /**
     * Apply inverse irreversible component transformation to obtain requested
     * component from specified block of data. Whatever the type of requested
     * DataBlk, it always returns a DataBlkFloat.
     *
     * @param blk Determine the rectangular area to return
     *
     * @param c The index of the requested component
     *
     * @return Data of requested component
     * */
    private DataBlk invICT(DataBlk blk,int c){
        if(c>=3 && c<getNumComps()) {
            // Requesting a component whose index is greater than 3            
            int k,k0,k1,k2,mink,i;
            int w = blk.w; //width of output block
            int h = blk.h; //height of ouput block

            int outdata[]; // array of output data

            //Reference to output block data array
            outdata = (int[]) blk.getData();

            //Create data array of blk if necessary
            if( outdata == null ) {
                outdata = new int[h * w];
                blk.setData(outdata);
            }

            // Variables
            DataBlkFloat indb = new DataBlkFloat(blk.ulx,blk.uly,w,h);
            float indata[]; // input data array

            // Get the input data
            // (returned block may be larger than requested one)
            src.getInternCompData(indb,c);
            indata = (float[]) indb.getData();

            // Copy the data converting from int to int
            k = w*h-1;
            k0 = indb.offset+(h-1)*indb.scanw+w-1;
            for (i=h-1; i >=0; i--) {
                for (mink = k-w; k > mink; k--, k0--) {
                    outdata[k] = (int) (indata[k0]);
                }
                // Jump to beggining of previous line in input
                k0 -= indb.scanw - w;
            }

            // Set the progressivity and offset
            blk.progressive = indb.progressive;
            blk.offset = 0;
            blk.scanw = w;
        }

        // If asking a component for the first time for this block,
        // do transform for the 3 components
        else if((outdata[c] == null)||
            (dbi.ulx > blk.ulx) || (dbi.uly > blk.uly) ||
            (dbi.ulx+dbi.w < blk.ulx+blk.w) ||
            (dbi.uly+dbi.h < blk.uly+blk.h)) {
            int k,k0,k1,k2,mink,i;
            int w = blk.w; //width of output block
            int h = blk.h; //height of ouput block

            //Reference to output block data array
            outdata[c] = (int[]) blk.getData();

            //Create data array of blk if necessary
            if(outdata[c] == null || outdata[c].length!=w*h){
                outdata[c] = new int[h * w];
                blk.setData(outdata[c]);
            }

            outdata[(c+1)%3] = new int[outdata[c].length];
            outdata[(c+2)%3] = new int[outdata[c].length];

            if(block0==null || block0.getDataType()!=DataBlk.TYPE_FLOAT)
                block0 = new DataBlkFloat();
            if(block2==null || block2.getDataType()!=DataBlk.TYPE_FLOAT)
                block2 = new DataBlkFloat();
            if(block1==null || block1.getDataType()!=DataBlk.TYPE_FLOAT)
                block1 = new DataBlkFloat();
            block0.w = block2.w = block1.w = blk.w;
            block0.h = block2.h = block1.h = blk.h;
            block0.ulx = block2.ulx = block1.ulx = blk.ulx;
            block0.uly = block2.uly = block1.uly = blk.uly;

            float data0[],data1[],data2[]; // input data arrays

            // Fill in buffer blocks (to be read only)
            // Returned blocks may have different size and position
            block0 = (DataBlkFloat)src.getInternCompData(block0, 0);
            data0  = (float[]) block0.getData();
            block2 = (DataBlkFloat)src.getInternCompData(block2, 1);
            data2 = (float[]) block2.getData();
            block1 = (DataBlkFloat)src.getInternCompData(block1, 2);
            data1 = (float[]) block1.getData();

            // Set the progressiveness of the output data
            blk.progressive = block0.progressive || block1.progressive ||
                block2.progressive;
            blk.offset = 0;
            blk.scanw = w;

            // set attributes of the DataBlk used for buffering
            dbi.progressive = blk.progressive;
            dbi.ulx = blk.ulx;
            dbi.uly = blk.uly;
            dbi.w = blk.w;
            dbi.h = blk.h;

            //Perform conversion

            // Initialize general indexes
            k = w*h-1;
            k0 = block0.offset+(h-1)*block0.scanw+w-1;
            k2 = block2.offset+(h-1)*block2.scanw+w-1;
            k1 = block1.offset+(h-1)*block1.scanw+w-1;

            for( i = h-1; i >=0; i--){
                for(mink = k-w; k > mink; k--, k0--, k2--, k1--){
                    outdata[0][k] = (int)(data0[k0]+1.402f*data1[k1]+0.5f);
                    outdata[1][k] =
                        (int) (data0[k0]-0.34413f*data2[k2]-0.71414f*data1[k1]
                               + 0.5f);
                    outdata[2][k] = (int)(data0[k0]+1.772f*data2[k2]+0.5f);
                }
                // Jump to beggining of previous line in input
                k0 -= block0.scanw - w;
                k2 -= block2.scanw - w;
                k1 -= block1.scanw - w;
            }
            outdata[c] = null;
        }
        else if((c>=0)&&(c<=3)){//Asking for the 2nd or 3rd block component
            blk.setData(outdata[c]);
            blk.progressive = dbi.progressive;
            blk.offset = (blk.uly-dbi.uly)*dbi.w+blk.ulx-dbi.ulx;
            blk.scanw = dbi.w;
            outdata[c] = null;
        } else {
            // Requesting a non valid component index
            throw new IllegalArgumentException();
        }
        return blk;
    }

        /**
     * Changes the current tile, given the new indexes. An
     * IllegalArgumentException is thrown if the indexes do not
     * correspond to a valid tile.
     *
     * <P>This default implementation changes the tile in the source
     * and re-initializes properly component transformation variables..
     *
     * @param x The horizontal index of the tile.
     *
     * @param y The vertical index of the new tile.
     *
     * */
    public void setTile(int x, int y) {
        src.setTile(x,y);
        tIdx = getTileIdx(); // index of the current tile

        // initializations
        if( ((Integer)cts.getTileDef(tIdx)).intValue()==NONE )
            transfType = NONE;
        else {
            int nc = src.getNumComps()> 3 ? 3 : src.getNumComps();
            int rev = 0;
            for(int c=0; c<nc; c++)
                rev += (wfs.isReversible(tIdx,c)?1:0);
            if(rev==3){
                // All WT are reversible
                transfType = INV_RCT;
            }
            else if(rev==0){
                // All WT irreversible
                transfType = INV_ICT;
            }
            else{
                // Error
                throw new IllegalArgumentException("Wavelet transformation and "+
                                                   "component transformation"+
                                                   " not coherent in tile"+tIdx);
            }
        }
    }

    /**
     * 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 default implementation just advances to the next tile
     * in the source and re-initializes properly component
     * transformation variables.
     *
     * */
    public void nextTile() {
        src.nextTile();
        tIdx = getTileIdx(); // index of the current tile

        // initializations
        if( ((Integer)cts.getTileDef(tIdx)).intValue()==NONE )
            transfType = NONE;
        else {
            int nc = src.getNumComps() > 3 ? 3 : src.getNumComps();
            int rev = 0;
            for(int c=0; c<nc; c++)
                rev += (wfs.isReversible(tIdx,c)?1:0);
            if(rev==3){
                // All WT are reversible
                transfType = INV_RCT;
            }
            else if(rev==0){
                // All WT irreversible
                transfType = INV_ICT;
            }
            else{
                // Error
                throw new IllegalArgumentException("Wavelet transformation and "+
                                                   "component transformation"+
                                                   " not coherent in tile"+tIdx);
            }
        }
    }

}