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/*
* CVS Identifier:
*
* $Id: ForwCompTransf.java,v 1.20 2001/09/14 09:14:57 grosbois Exp $
*
* Class:               ForwCompTransf
*
* Description:         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.
* */
using System;
using CSJ2K.j2k.wavelet.analysis;
using CSJ2K.j2k.wavelet;
using CSJ2K.j2k.encoder;
using CSJ2K.j2k.image;
using CSJ2K.j2k.util;
using CSJ2K.j2k;
namespace CSJ2K.j2k.image.forwcomptransf
{
        
        /// <summary> This class apply component transformations to the tiles depending on user
        /// specifications. 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).
        /// 
        /// </summary>
        /// <seealso cref="ModuleSpec">
        /// 
        /// </seealso>
        public class ForwCompTransf:ImgDataAdapter, BlkImgDataSrc
        {
                /// <summary> 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.
                /// 
                /// </summary>
                /// <returns> the options name, their synopsis and their explanation, or null
                /// if no options are supported.
                /// 
                /// </returns>
                public static System.String[][] ParameterInfo
                {
                        get
                        {
                                return pinfo;
                        }
                        
                }
                /// <summary> 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).
                /// 
                /// </summary>
                /// <returns> Reversibility of component transformation in current tile
                /// 
                /// </returns>
                virtual public bool Reversible
                {
                        get
                        {
                                switch (transfType)
                                {
                                        
                                        case NONE: 
                                        case FORW_RCT: 
                                                return true;
                                        
                                        case FORW_ICT: 
                                                return false;
                                        
                                        default: 
                                                throw new System.ArgumentException("Non JPEG 2000 part I" + " component transformation");
                                        
                                }
                        }
                        
                }
                /// <summary>Identifier for no component transformation. Value is 0. </summary>
                public const int NONE = 0;
                
                /// <summary>Identifier for the Forward Reversible Component Transformation
                /// (FORW_RCT). Value is 1. 
                /// </summary>
                public const int FORW_RCT = 1;
                
                /// <summary>Identifier for the Forward Irreversible Component Transformation
                /// (FORW_ICT). Value is 2 
                /// </summary>
                public const int FORW_ICT = 2;
                
                /// <summary>The source of image data </summary>
                private BlkImgDataSrc src;
                
                /// <summary>The component transformations specifications </summary>
                private CompTransfSpec cts;
                
                /// <summary>The wavelet filter specifications </summary>
                private AnWTFilterSpec wfs;
                
                /// <summary>The type of the current component transformation. JPEG 2000 part 1
                /// supports only NONE, FORW_RCT and FORW_ICT types 
                /// </summary>
                private int transfType = NONE;
                
                /// <summary>The bit-depths of transformed components </summary>
                private int[] tdepth;
                
                /// <summary>Output block used instead of the one provided as an argument if the
                /// later is DataBlkFloat.
                /// </summary>
                private DataBlk outBlk;
                
                /// <summary>Block used to request component with index 0 </summary>
                private DataBlkInt block0;
                
                /// <summary>Block used to request component with index 1</summary>
                private DataBlkInt block1;
                
                /// <summary>Block used to request component with index 2</summary>
                private DataBlkInt block2;
                
                /// <summary> Constructs a new ForwCompTransf object that operates on the specified
                /// source of image data.
                /// 
                /// </summary>
                /// <param name="imgSrc">The source from where to get the data to be transformed
                /// 
                /// </param>
                /// <param name="encSpec">The encoder specifications
                /// 
                /// </param>
                /// <seealso cref="BlkImgDataSrc">
                /// 
                /// </seealso>
                public ForwCompTransf(BlkImgDataSrc imgSrc, EncoderSpecs encSpec):base(imgSrc)
                {
                        this.cts = encSpec.cts;
                        this.wfs = encSpec.wfs;
                        src = imgSrc;
                }
                
                /// <summary>The prefix for component transformation type: 'M' </summary>
                public const char OPT_PREFIX = 'M';
                
                /// <summary>The list of parameters that is accepted by the forward component
                /// transformation module. Options start with an 'M'. 
                /// </summary>
                //UPGRADE_NOTE: Final was removed from the declaration of 'pinfo'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
                private static readonly System.String[][] pinfo = new System.String[][]{new System.String[]{"Mct", "[<tile index>] [on|off] ...", "Specifies in which tiles to use a multiple component transform. " + "Note that this multiple component transform can only be applied " + "in tiles that contain at least three components and whose " + "components are processed with the same wavelet filters and " + "quantization type. " + "If the wavelet transform is reversible (w5x3 filter), the " + "Reversible Component Transformation (RCT) is applied. If not " + "(w9x7 filter), the Irreversible Component Transformation (ICT)" + " is used.", null}};
                
                /// <summary> 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.</p>
                /// 
                /// </summary>
                /// <param name="c">The index of the component.
                /// 
                /// </param>
                /// <returns> The value of the fixed point position of the source since the
                /// color transform does not affect it.
                /// 
                /// </returns>
                public virtual int getFixedPoint(int c)
                {
                        return src.getFixedPoint(c);
                }
                
                /// <summary> Calculates the bitdepths of the transformed components, given the
                /// bitdepth of the un-transformed components and the component
                /// transformation type.
                /// 
                /// </summary>
                /// <param name="ntdepth">The bitdepth of each non-transformed components.
                /// 
                /// </param>
                /// <param name="ttype">The type ID of the component transformation.
                /// 
                /// </param>
                /// <param name="tdepth">If not null the results are stored in this array,
                /// otherwise a new array is allocated and returned.
                /// 
                /// </param>
                /// <returns> The bitdepth of each transformed component.
                /// 
                /// </returns>
                public static int[] calcMixedBitDepths(int[] ntdepth, int ttype, int[] tdepth)
                {
                        
                        if (ntdepth.Length < 3 && ttype != NONE)
                        {
                                throw new System.ArgumentException();
                        }
                        
                        if (tdepth == null)
                        {
                                tdepth = new int[ntdepth.Length];
                        }
                        
                        switch (ttype)
                        {
                                
                                case NONE: 
                                        Array.Copy(ntdepth, 0, tdepth, 0, ntdepth.Length);
                                        break;
                                
                                case FORW_RCT: 
                                        if (ntdepth.Length > 3)
                                        {
                                                Array.Copy(ntdepth, 3, tdepth, 3, ntdepth.Length - 3);
                                        }
                                        // The formulas are:
                                        // tdepth[0] = ceil(log2(2^(ntdepth[0])+2^ntdepth[1]+
                                        //                        2^(ntdepth[2])))-2+1
                                        // tdepth[1] = ceil(log2(2^(ntdepth[1])+2^(ntdepth[2])-1))+1
                                        // tdepth[2] = ceil(log2(2^(ntdepth[0])+2^(ntdepth[1])-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 << ntdepth[0]) + (2 << ntdepth[1]) + (1 << ntdepth[2]) - 1) - 2 + 1;
                                        tdepth[1] = MathUtil.log2((1 << ntdepth[2]) + (1 << ntdepth[1]) - 1) + 1;
                                        tdepth[2] = MathUtil.log2((1 << ntdepth[0]) + (1 << ntdepth[1]) - 1) + 1;
                                        break;
                                
                                case FORW_ICT: 
                                        if (ntdepth.Length > 3)
                                        {
                                                Array.Copy(ntdepth, 3, tdepth, 3, ntdepth.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.
                                        //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
                                        tdepth[0] = MathUtil.log2((int) System.Math.Floor((1 << ntdepth[0]) * 0.299072 + (1 << ntdepth[1]) * 0.586914 + (1 << ntdepth[2]) * 0.114014) - 1) + 1;
                                        //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
                                        tdepth[1] = MathUtil.log2((int) System.Math.Floor((1 << ntdepth[0]) * 0.168701 + (1 << ntdepth[1]) * 0.331299 + (1 << ntdepth[2]) * 0.5) - 1) + 1;
                                        //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
                                        tdepth[2] = MathUtil.log2((int) System.Math.Floor((1 << ntdepth[0]) * 0.5 + (1 << ntdepth[1]) * 0.418701 + (1 << ntdepth[2]) * 0.081299) - 1) + 1;
                                        break;
                                }
                        
                        return tdepth;
                }
                
                /// <summary> Initialize some variables used with RCT. It must be called, at least,
                /// at the beginning of each new tile.
                /// 
                /// </summary>
                private void  initForwRCT()
                {
                        int i;
                        int tIdx = TileIdx;
                        
                        if (src.NumComps < 3)
                        {
                                throw new System.ArgumentException();
                        }
                        // Check that the 3 components have the same dimensions
                        if (src.getTileCompWidth(tIdx, 0) != src.getTileCompWidth(tIdx, 1) || src.getTileCompWidth(tIdx, 0) != src.getTileCompWidth(tIdx, 2) || src.getTileCompHeight(tIdx, 0) != src.getTileCompHeight(tIdx, 1) || src.getTileCompHeight(tIdx, 0) != src.getTileCompHeight(tIdx, 2))
                        {
                                throw new System.ArgumentException("Can not use RCT " + "on components with different " + "dimensions");
                        }
                        // Initialize bitdepths
                        int[] utd; // Premix bitdepths
                        utd = new int[src.NumComps];
                        for (i = utd.Length - 1; i >= 0; i--)
                        {
                                utd[i] = src.getNomRangeBits(i);
                        }
                        tdepth = calcMixedBitDepths(utd, FORW_RCT, null);
                }
                
                /// <summary> Initialize some variables used with ICT. It must be called, at least,
                /// at the beginning of a new tile.
                /// 
                /// </summary>
                private void  initForwICT()
                {
                        int i;
                        int tIdx = TileIdx;
                        
                        if (src.NumComps < 3)
                        {
                                throw new System.ArgumentException();
                        }
                        // Check that the 3 components have the same dimensions
                        if (src.getTileCompWidth(tIdx, 0) != src.getTileCompWidth(tIdx, 1) || src.getTileCompWidth(tIdx, 0) != src.getTileCompWidth(tIdx, 2) || src.getTileCompHeight(tIdx, 0) != src.getTileCompHeight(tIdx, 1) || src.getTileCompHeight(tIdx, 0) != src.getTileCompHeight(tIdx, 2))
                        {
                                throw new System.ArgumentException("Can not use ICT " + "on components with different " + "dimensions");
                        }
                        // Initialize bitdepths
                        int[] utd; // Premix bitdepths
                        utd = new int[src.NumComps];
                        for (i = utd.Length - 1; i >= 0; i--)
                        {
                                utd[i] = src.getNomRangeBits(i);
                        }
                        tdepth = calcMixedBitDepths(utd, FORW_ICT, null);
                }
                
                /// <summary> Returns a string with a descriptive text of which forward component
                /// transformation is used. This can be either "Forward RCT" or "Forward
                /// ICT" or "No component transformation" depending on the current tile.
                /// 
                /// </summary>
                /// <returns> A descriptive string
                /// 
                /// </returns>
                public override System.String ToString()
                {
                        switch (transfType)
                        {
                                
                                case FORW_RCT: 
                                        return "Forward RCT";
                                
                                case FORW_ICT: 
                                        return "Forward ICT";
                                
                                case NONE: 
                                        return "No component transformation";
                                
                                default: 
                                        throw new System.ArgumentException("Non JPEG 2000 part I" + " component transformation");
                                
                        }
                }
                
                /// <summary> Returns the number of bits, referred to as the "range bits",
                /// corresponding to the nominal range of the data in the specified
                /// component and in the current tile. If this number is <i>b</i> 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. Note that this value can be
                /// affected by the multiple component transform.
                /// 
                /// </summary>
                /// <param name="c">The index of the component.
                /// 
                /// </param>
                /// <returns> The bitdepth of component 'c' after mixing.
                /// 
                /// </returns>
                public override int getNomRangeBits(int c)
                {
                        switch (transfType)
                        {
                                
                                case FORW_RCT: 
                                case FORW_ICT: 
                                        return tdepth[c];
                                
                                case NONE: 
                                        return src.getNomRangeBits(c);
                                
                                default: 
                                        throw new System.ArgumentException("Non JPEG 2000 part I" + " component transformation");
                                
                        }
                }
                
                /// <summary> Apply forward 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.</p>
                /// 
                /// </summary>
                /// <param name="blk">Determines the rectangular area to return, and the data is
                /// returned in this object.
                /// 
                /// </param>
                /// <param name="c">Index of the output component.
                /// 
                /// </param>
                /// <returns> The requested DataBlk
                /// 
                /// </returns>
                /// <seealso cref="BlkImgDataSrc.getCompData">
                /// 
                /// </seealso>
                public virtual 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);
                        }
                }
                
                /// <summary> Apply the 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 (forwRCT or forwICT).
                /// 
                /// </summary>
                /// <seealso cref="forwRCT">
                /// 
                /// </seealso>
                /// <seealso cref="forwICT">
                /// 
                /// </seealso>
                /// <param name="blk">Determines the rectangular area to return.
                /// 
                /// </param>
                /// <param name="c">Index of the output component.
                /// 
                /// </param>
                /// <returns> The requested DataBlk
                /// 
                /// </returns>
                public virtual DataBlk getInternCompData(DataBlk blk, int c)
                {
                        switch (transfType)
                        {
                                
                                case NONE: 
                                        return src.getInternCompData(blk, c);
                                
                                case FORW_RCT: 
                                        return forwRCT(blk, c);
                                
                                case FORW_ICT: 
                                        return forwICT(blk, c);
                                
                                default: 
                                        throw new System.ArgumentException("Non JPEG 2000 part 1 " + "component" + " transformation for tile: " + tIdx);
                                
                        }
                }
                
                /// <summary> Apply forward component transformation to obtain requested component
                /// from specified block of data. Whatever the type of requested DataBlk,
                /// it always returns a DataBlkInt.
                /// 
                /// </summary>
                /// <param name="blk">Determine the rectangular area to return 
                /// 
                /// </param>
                /// <param name="c">The index of the requested component
                /// 
                /// </param>
                /// <returns> Data of requested component
                /// 
                /// </returns>
                private DataBlk forwRCT(DataBlk blk, int c)
                {
                        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
                        
                        //If asking for Yr, Ur or Vr do transform
                        if (c >= 0 && c <= 2)
                        {
                                // Check that request data type is int
                                if (blk.DataType != DataBlk.TYPE_INT)
                                {
                                        if (outBlk == null || outBlk.DataType != DataBlk.TYPE_INT)
                                        {
                                                outBlk = new DataBlkInt();
                                        }
                                        outBlk.w = w;
                                        outBlk.h = h;
                                        outBlk.ulx = blk.ulx;
                                        outBlk.uly = blk.uly;
                                        blk = outBlk;
                                }
                                
                                //Reference to output block data array
                                outdata = (int[]) blk.Data;
                                
                                //Create data array of blk if necessary
                                if (outdata == null || outdata.Length < h * w)
                                {
                                        outdata = new int[h * w];
                                        blk.Data = outdata;
                                }
                                
                                // Block buffers for input RGB data
                                int[] data0, data1, bdata; // input data arrays
                                
                                if (block0 == null)
                                        block0 = new DataBlkInt();
                                if (block1 == null)
                                        block1 = new DataBlkInt();
                                if (block2 == null)
                                        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;
                                
                                //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.Data;
                                block1 = (DataBlkInt) src.getInternCompData(block1, 1);
                                data1 = (int[]) block1.Data;
                                block2 = (DataBlkInt) src.getInternCompData(block2, 2);
                                bdata = (int[]) block2.Data;
                                
                                // Set the progressiveness of the output data
                                blk.progressive = block0.progressive || block1.progressive || block2.progressive;
                                blk.offset = 0;
                                blk.scanw = w;
                                
                                //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;
                                
                                switch (c)
                                {
                                        
                                        case 0:  //RGB to Yr conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k0--, k1--, k2--)
                                                        {
                                                                // Use int arithmetic with 12 fractional bits
                                                                // and rounding
                                                                outdata[k] = (data0[k] + 2 * data1[k] + bdata[k]) >> 2; // Same as / 4
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k0 -= (block0.scanw - w);
                                                        k1 -= (block1.scanw - w);
                                                        k2 -= (block2.scanw - w);
                                                }
                                                break;
                                        
                                        
                                        case 1:  //RGB to Ur conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k1--, k2--)
                                                        {
                                                                // Use int arithmetic with 12 fractional bits
                                                                // and rounding
                                                                outdata[k] = bdata[k2] - data1[k1];
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k1 -= (block1.scanw - w);
                                                        k2 -= (block2.scanw - w);
                                                }
                                                break;
                                        
                                        
                                        case 2:  //RGB to Vr conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k0--, k1--)
                                                        {
                                                                // Use int arithmetic with 12 fractional bits
                                                                // and rounding
                                                                outdata[k] = data0[k0] - data1[k1];
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k0 -= (block0.scanw - w);
                                                        k1 -= (block1.scanw - w);
                                                }
                                                break;
                                        }
                        }
                        else if (c >= 3)
                        {
                                // Requesting a component which is not Y, Ur or Vr =>
                                // just pass the data            
                                return src.getInternCompData(blk, c);
                        }
                        else
                        {
                                // Requesting a non valid component index
                                throw new System.ArgumentException();
                        }
                        return blk;
                }
                
                /// <summary> Apply forward irreversible component transformation to obtain requested
                /// component from specified block of data. Whatever the type of requested
                /// DataBlk, it always returns a DataBlkFloat.
                /// 
                /// </summary>
                /// <param name="blk">Determine the rectangular area to return 
                /// 
                /// </param>
                /// <param name="c">The index of the requested component
                /// 
                /// </param>
                /// <returns> Data of requested component
                /// 
                /// </returns>
                private DataBlk forwICT(DataBlk blk, int c)
                {
                        int k, k0, k1, k2, mink, i;
                        int w = blk.w; //width of output block
                        int h = blk.h; //height of ouput block
                        float[] outdata; //array of output data
                        
                        if (blk.DataType != DataBlk.TYPE_FLOAT)
                        {
                                if (outBlk == null || outBlk.DataType != DataBlk.TYPE_FLOAT)
                                {
                                        outBlk = new DataBlkFloat();
                                }
                                outBlk.w = w;
                                outBlk.h = h;
                                outBlk.ulx = blk.ulx;
                                outBlk.uly = blk.uly;
                                blk = outBlk;
                        }
                        
                        //Reference to output block data array
                        outdata = (float[]) blk.Data;
                        
                        //Create data array of blk if necessary
                        if (outdata == null || outdata.Length < w * h)
                        {
                                outdata = new float[h * w];
                                blk.Data = outdata;
                        }
                        
                        //If asking for Y, Cb or Cr do transform
                        if (c >= 0 && c <= 2)
                        {
                                
                                int[] data0, data1, data2; // input data arrays
                                
                                if (block0 == null)
                                {
                                        block0 = new DataBlkInt();
                                }
                                if (block1 == null)
                                {
                                        block1 = new DataBlkInt();
                                }
                                if (block2 == null)
                                {
                                        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;
                                
                                // Returned blocks may have different size and position
                                block0 = (DataBlkInt) src.getInternCompData(block0, 0);
                                data0 = (int[]) block0.Data;
                                block1 = (DataBlkInt) src.getInternCompData(block1, 1);
                                data1 = (int[]) block1.Data;
                                block2 = (DataBlkInt) src.getInternCompData(block2, 2);
                                data2 = (int[]) block2.Data;
                                
                                // Set the progressiveness of the output data
                                blk.progressive = block0.progressive || block1.progressive || block2.progressive;
                                blk.offset = 0;
                                blk.scanw = w;
                                
                                //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;
                                
                                switch (c)
                                {
                                        
                                        case 0: 
                                                //RGB to Y conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k0--, k1--, k2--)
                                                        {
                                                                outdata[k] = 0.299f * data0[k0] + 0.587f * data1[k1] + 0.114f * data2[k2];
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k0 -= (block0.scanw - w);
                                                        k1 -= (block1.scanw - w);
                                                        k2 -= (block2.scanw - w);
                                                }
                                                break;
                                        
                                        
                                        case 1: 
                                                //RGB to Cb conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k0--, k1--, k2--)
                                                        {
                                                                outdata[k] = (- 0.16875f) * data0[k0] - 0.33126f * data1[k1] + 0.5f * data2[k2];
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k0 -= (block0.scanw - w);
                                                        k1 -= (block1.scanw - w);
                                                        k2 -= (block2.scanw - w);
                                                }
                                                break;
                                        
                                        
                                        case 2: 
                                                //RGB to Cr conversion
                                                for (i = h - 1; i >= 0; i--)
                                                {
                                                        for (mink = k - w; k > mink; k--, k0--, k1--, k2--)
                                                        {
                                                                outdata[k] = 0.5f * data0[k0] - 0.41869f * data1[k1] - 0.08131f * data2[k2];
                                                        }
                                                        // Jump to beggining of previous line in input
                                                        k0 -= (block0.scanw - w);
                                                        k1 -= (block1.scanw - w);
                                                        k2 -= (block2.scanw - w);
                                                }
                                                break;
                                        }
                        }
                        else if (c >= 3)
                        {
                                // Requesting a component which is not Y, Cb or Cr =>
                                // just pass the data
                                
                                // Variables
                                DataBlkInt indb = new DataBlkInt(blk.ulx, blk.uly, w, h);
                                int[] indata; // input data array
                                
                                // Get the input data
                                // (returned block may be larger than requested one)
                                src.getInternCompData(indb, c);
                                indata = (int[]) indb.Data;
                                
                                // Copy the data converting from int to float
                                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--)
                                        {
                                                //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
                                                outdata[k] = (float) indata[k0];
                                        }
                                        // Jump to beggining of next line in input
                                        k0 += indb.w - w;
                                }
                                
                                // Set the progressivity
                                blk.progressive = indb.progressive;
                                blk.offset = 0;
                                blk.scanw = w;
                                return blk;
                        }
                        else
                        {
                                // Requesting a non valid component index
                                throw new System.ArgumentException();
                        }
                        return blk;
                }
                
                /// <summary> 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..</p>
                /// 
                /// </summary>
                /// <param name="x">The horizontal index of the tile.
                /// 
                /// </param>
                /// <param name="y">The vertical index of the new tile.
                /// 
                /// </param>
                public override void  setTile(int x, int y)
                {
                        src.setTile(x, y);
                        tIdx = TileIdx; // index of the current tile
                        
                        // initializations
                        System.String str = (System.String) cts.getTileDef(tIdx);
                        if (str.Equals("none"))
                        {
                                transfType = NONE;
                        }
                        else if (str.Equals("rct"))
                        {
                                transfType = FORW_RCT;
                                initForwRCT();
                        }
                        else if (str.Equals("ict"))
                        {
                                transfType = FORW_ICT;
                                initForwICT();
                        }
                        else
                        {
                                throw new System.ArgumentException("Component transformation" + " not recognized");
                        }
                }
                
                /// <summary> Goes to the next tile, in standard scan-line order (by rows then by
                /// 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.</p>
                /// 
                /// </summary>
                public override void  nextTile()
                {
                        src.nextTile();
                        tIdx = TileIdx; // index of the current tile
                        
                        // initializations
                        System.String str = (System.String) cts.getTileDef(tIdx);
                        if (str.Equals("none"))
                        {
                                transfType = NONE;
                        }
                        else if (str.Equals("rct"))
                        {
                                transfType = FORW_RCT;
                                initForwRCT();
                        }
                        else if (str.Equals("ict"))
                        {
                                transfType = FORW_ICT;
                                initForwICT();
                        }
                        else
                        {
                                throw new System.ArgumentException("Component transformation" + " not recognized");
                        }
                }
        }
}

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