iTextSharp.text.pdf.PdfFunction.Type4 C# (CSharp) Метод

        public static PdfFunction Type4(PdfWriter writer, float[] domain, float[] range, string postscript) {
            byte[] b = new byte[postscript.Length];
                for (int k = 0; k < b.Length; ++k)
                    b[k] = (byte)postscript[k];
            PdfFunction func = new PdfFunction(writer);
            func.dictionary = new PdfStream(b);
            ((PdfStream)func.dictionary).FlateCompress(writer.CompressionLevel);
            func.dictionary.Put(PdfName.FUNCTIONTYPE, new PdfNumber(4));
            func.dictionary.Put(PdfName.DOMAIN, new PdfArray(domain));
            func.dictionary.Put(PdfName.RANGE, new PdfArray(range));
            return func;
        }
    }

        public virtual PdfObject GetPdfObject(PdfWriter writer)
        {
            PdfArray array = new PdfArray(PdfName.DEVICEN);

            PdfArray colorants = new PdfArray();

            float[]       colorantsRanges = new float[spotColors.Length * 2];
            PdfDictionary colorantsDict   = new PdfDictionary();
            String        psFunFooter     = "";

            int numberOfColorants = spotColors.Length;

            float[,] CMYK = new float[4, numberOfColorants];
            int i = 0;

            for (; i < numberOfColorants; i++)
            {
                PdfSpotColor spotColorant = spotColors[i];
                colorantsRanges[2 * i]     = 0;
                colorantsRanges[2 * i + 1] = 1;
                colorants.Add(spotColorant.Name);
                if (colorantsDict.Get(spotColorant.Name) != null)
                {
                    throw new Exception(MessageLocalization.GetComposedMessage("devicen.component.names.shall.be.different"));
                }
                if (colorantsDetails != null)
                {
                    colorantsDict.Put(spotColorant.Name, colorantsDetails[i].IndirectReference);
                }
                else
                {
                    colorantsDict.Put(spotColorant.Name, spotColorant.GetPdfObject(writer));
                }
                BaseColor color = spotColorant.AlternativeCS;
                if (color is ExtendedColor)
                {
                    int type = ((ExtendedColor)color).Type;
                    switch (type)
                    {
                    case ExtendedColor.TYPE_GRAY:
                        CMYK[0, i] = 0;
                        CMYK[1, i] = 0;
                        CMYK[2, i] = 0;
                        CMYK[3, i] = 1 - ((GrayColor)color).Gray;
                        break;

                    case ExtendedColor.TYPE_CMYK:
                        CMYK[0, i] = ((CMYKColor)color).Cyan;
                        CMYK[1, i] = ((CMYKColor)color).Magenta;
                        CMYK[2, i] = ((CMYKColor)color).Yellow;
                        CMYK[3, i] = ((CMYKColor)color).Black;
                        break;

                    case ExtendedColor.TYPE_LAB:
                        CMYKColor cmyk = ((LabColor)color).ToCmyk();
                        CMYK[0, i] = cmyk.Cyan;
                        CMYK[1, i] = cmyk.Magenta;
                        CMYK[2, i] = cmyk.Yellow;
                        CMYK[3, i] = cmyk.Black;
                        break;

                    default:
                        throw new Exception(
                                  MessageLocalization.GetComposedMessage(
                                      "only.rgb.gray.and.cmyk.are.supported.as.alternative.color.spaces"));
                    }
                }
                else
                {
                    float r = color.R;
                    float g = color.G;
                    float b = color.B;
                    float computedC = 0, computedM = 0, computedY = 0, computedK = 0;

                    // BLACK
                    if (r == 0 && g == 0 && b == 0)
                    {
                        computedK = 1;
                    }
                    else
                    {
                        computedC = 1 - (r / 255);
                        computedM = 1 - (g / 255);
                        computedY = 1 - (b / 255);

                        float minCMY = Math.Min(computedC,
                                                Math.Min(computedM, computedY));
                        computedC = (computedC - minCMY) / (1 - minCMY);
                        computedM = (computedM - minCMY) / (1 - minCMY);
                        computedY = (computedY - minCMY) / (1 - minCMY);
                        computedK = minCMY;
                    }
                    CMYK[0, i] = computedC;
                    CMYK[1, i] = computedM;
                    CMYK[2, i] = computedY;
                    CMYK[3, i] = computedK;
                }
                psFunFooter += "pop ";
            }
            array.Add(colorants);

            String psFunHeader = String.Format(NumberFormatInfo.InvariantInfo, "1.000000 {0} 1 roll ", numberOfColorants + 1);

            array.Add(PdfName.DEVICECMYK);
            psFunHeader = psFunHeader + psFunHeader + psFunHeader + psFunHeader;
            String psFun = "";

            i = numberOfColorants + 4;
            for (; i > numberOfColorants; i--)
            {
                psFun += String.Format(NumberFormatInfo.InvariantInfo, "{0} -1 roll ", i);
                for (int j = numberOfColorants; j > 0; j--)
                {
                    psFun += String.Format(NumberFormatInfo.InvariantInfo, "{0} index {1} mul 1.000000 cvr exch sub mul ", j,
                                           CMYK[numberOfColorants + 4 - i, numberOfColorants - j]);
                }
                psFun += String.Format(NumberFormatInfo.InvariantInfo, "1.000000 cvr exch sub {0} 1 roll ", i);
            }

            PdfFunction func = PdfFunction.Type4(writer, colorantsRanges, new float[] { 0, 1, 0, 1, 0, 1, 0, 1 },
                                                 "{ " + psFunHeader + psFun + psFunFooter + "}");

            array.Add(func.Reference);

            PdfDictionary attr = new PdfDictionary();

            attr.Put(PdfName.SUBTYPE, PdfName.NCHANNEL);
            attr.Put(PdfName.COLORANTS, colorantsDict);
            array.Add(attr);

            return(array);
        }