GfxImageColorMap::GfxImageColorMap(int bitsA, Object *decode,
				   GfxColorSpace *colorSpaceA) {
  GfxIndexedColorSpace *indexedCS;
  GfxSeparationColorSpace *sepCS;
  int maxPixel, indexHigh;
  Guchar *lookup2;
  Function *sepFunc;
  Object obj;
  double x[gfxColorMaxComps];
  double y[gfxColorMaxComps];
  int i, j, k, byte;
  double mapped;

  ok = gTrue;

  bits = bitsA;
  maxPixel = (1 << bits) - 1;
  colorSpace = colorSpaceA;

  if (maxPixel > 255) maxPixel = 255;

  for (k = 0; k < gfxColorMaxComps; ++k) {
    lookup[k] = NULL;
  }

  if (decode->isNull()) {
    nComps = colorSpace->getNComps();
    colorSpace->getDefaultRanges(decodeLow, decodeRange, maxPixel);
  } else if (decode->isArray()) {
    nComps = decode->arrayGetLength() / 2;
    if (nComps != colorSpace->getNComps()) {
      goto err1;
    }
    for (i = 0; i < nComps; ++i) {
      decode->arrayGet(2*i, &obj);
      if (!obj.isNum()) {
	goto err2;
      }
      decodeLow[i] = obj.getNum();
      obj.free();
      decode->arrayGet(2*i+1, &obj);
      if (!obj.isNum()) {
	goto err2;
      }
      decodeRange[i] = obj.getNum() - decodeLow[i];
      obj.free();
    }
  } else {
    goto err1;
  }

  colorSpace2 = NULL;
  nComps2 = 0;
  if (colorSpace->getMode() == csIndexed) {
    indexedCS = (GfxIndexedColorSpace *)colorSpace;
    colorSpace2 = indexedCS->getBase();
    indexHigh = indexedCS->getIndexHigh();
     nComps2 = colorSpace2->getNComps();
     lookup2 = indexedCS->getLookup();
     colorSpace2->getDefaultRanges(x, y, indexHigh);
    byte_lookup = (Guchar *)gmallocn ((maxPixel + 1), nComps2);
     for (k = 0; k < nComps2; ++k) {
       lookup[k] = (GfxColorComp *)gmallocn(maxPixel + 1,
 					   sizeof(GfxColorComp));
      for (i = 0; i <= maxPixel; ++i) {
	j = (int)(decodeLow[0] + (i * decodeRange[0]) / maxPixel + 0.5);
	if (j < 0) {
	  j = 0;
	} else if (j > indexHigh) {
	  j = indexHigh;
	}

	mapped = x[k] + (lookup2[j*nComps2 + k] / 255.0) * y[k];
	lookup[k][i] = dblToCol(mapped);
	byte_lookup[i * nComps2 + k] = (Guchar) (mapped * 255);
      }
    }
  } else if (colorSpace->getMode() == csSeparation) {
    sepCS = (GfxSeparationColorSpace *)colorSpace;
    colorSpace2 = sepCS->getAlt();
    nComps2 = colorSpace2->getNComps();
    sepFunc = sepCS->getFunc();
    byte_lookup = (Guchar *)gmallocn ((maxPixel + 1), nComps2);
    for (k = 0; k < nComps2; ++k) {
      lookup[k] = (GfxColorComp *)gmallocn(maxPixel + 1,
					   sizeof(GfxColorComp));
      for (i = 0; i <= maxPixel; ++i) {
	x[0] = decodeLow[0] + (i * decodeRange[0]) / maxPixel;
	sepFunc->transform(x, y);
	lookup[k][i] = dblToCol(y[k]);
	byte_lookup[i*nComps2 + k] = (Guchar) (y[k] * 255);
      }
    }
  } else {
    byte_lookup = (Guchar *)gmallocn ((maxPixel + 1), nComps);
    for (k = 0; k < nComps; ++k) {
      lookup[k] = (GfxColorComp *)gmallocn(maxPixel + 1,
					   sizeof(GfxColorComp));
      for (i = 0; i <= maxPixel; ++i) {
	mapped = decodeLow[k] + (i * decodeRange[k]) / maxPixel;
	lookup[k][i] = dblToCol(mapped);
	byte = (int) (mapped * 255.0 + 0.5);
	if (byte < 0)  
	  byte = 0;  
	else if (byte > 255)  
	  byte = 255;  
	byte_lookup[i * nComps + k] = byte;	
      }
    }
  }

  return;

 err2:
  obj.free();
 err1:
  ok = gFalse;
  byte_lookup = NULL;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.