package gui;import jj2000.j2k.image.input.*;import jj2000.j2k.image.*;import jj2000.j2k.util.*;/** Class to display pgx files with signed data or bit-depth greater * than 8 bits. The data is rescaled in order to fit in the range * 0-255. */public class RescaleImgReader extends ImgDataAdapter implements BlkImgDataSrc {        /** Reference to the image reader instance */    private ImgReader src;    /** Flag indicating that source needs no rescaling */    private final static int NO_RESCALE = 0;    /** Flag indicating that source needs rescaling */    private final static int RESCALING = 1;    /** State of the rescaler */    private int rescaleMode = NO_RESCALE;    /** Whether or not input components are signed */    private boolean[] isSigned;    /** Bit-depth of each component */    private int[] bitDepth;    /** Check if input image reader needs rescaling. Note: an image     * reader needs rescaling if data are signed and/or component     * bit-depth is larger than 8bpp. */    public RescaleImgReader(ImgReader src) {	super(src);	this.src = src;	int nc = src.getNumComps();	isSigned = new boolean[nc];	bitDepth = new int[nc];	for(int c=0; c<nc; c++) {	    isSigned[c] = src.isOrigSigned(c);	    bitDepth[c] = src.getNomRangeBits(c);	    if(isSigned[c] || bitDepth[c]>8) {		rescaleMode = RESCALING;	    }	}    }    public int getFixedPoint(int c) {	return 0;    }     public DataBlk getInternCompData(DataBlk blk,int c) {	if(rescaleMode==NO_RESCALE) {	    return src.getInternCompData(blk,c);	} else {	    return rescaleBlk(src.getInternCompData(blk,c),c);	}    }    public DataBlk getCompData(DataBlk blk,int c) {	if(rescaleMode==NO_RESCALE) {	    return src.getCompData(blk,c);	} else {	    return rescaleBlk(src.getCompData(blk,c),c);	}    }    public int getNomRangeBits(int c) {	return 8;    }        public boolean isOrigSigned(int c) {	return false;    }    private DataBlk rescaleBlk(DataBlk blk,int c) {	int dataType = blk.getDataType();	switch(dataType) {	case DataBlk.TYPE_INT:	    int[] dataI = (int[])blk.getData();	    int maxI = (isSigned[c] ? 1<<(bitDepth[c]-1) : 1<<bitDepth[c])-1;	    int minI = isSigned[c] ? -(1<<(bitDepth[c]-1)) : 0;	    int rg = maxI-minI;	    int levShift = isSigned[c] ? 0 : 1<<(bitDepth[c]-1);	    int pos = blk.offset;	    for(int i=0; i<blk.h; i++, pos+=blk.scanw-blk.w) {		for(int j=0; j<blk.w; j++,pos++) {		    dataI[pos] = ((dataI[pos]+levShift-minI)*255/rg)-128;		}	    }	    break;	case DataBlk.TYPE_FLOAT:	    float[] dataF = (float[])blk.getData();	    float maxF = (isSigned[c] ? 1<<(bitDepth[c]-1) : 1<<bitDepth[c])-1;	    float minF = isSigned[c] ? -(1<<(bitDepth[c]-1)) : 0;	    float rgF = maxF-minF;	    float levShiftF = isSigned[c] ? 0 : 1<<(bitDepth[c]-1);	    int pos2 = blk.offset;	    for(int i=0; i<blk.h; i++, pos2+=blk.scanw-blk.w) {		for(int j=0; j<blk.w; j++,pos2++) {		    dataF[pos2] = ((dataF[pos2]+levShiftF-minF)*255/rgF)-128;		}	    }	    break;	default:	    throw new IllegalArgumentException("Unsupported data type");	}	return blk;    }}