iTextSharp.text.pdf.codec.PngImage.GetImage C# (CSharp) Метод

        Image GetImage()
        {
            ReadPng();
            int pal0 = 0;
            int palIdx = 0;
            palShades = false;
            if (trans != null) {
                for (int k = 0; k < trans.Length; ++k) {
                    int n = trans[k] & 0xff;
                    if (n == 0) {
                        ++pal0;
                        palIdx = k;
                    }
                    if (n != 0 && n != 255) {
                        palShades = true;
                        break;
                    }
                }
            }
            if ((colorType & 4) != 0)
                palShades = true;
            genBWMask = (!palShades && (pal0 > 1 || transRedGray >= 0));
            if (!palShades && !genBWMask && pal0 == 1) {
                additional.Put(PdfName.MASK, new PdfLiteral("["+palIdx+" "+palIdx+"]"));
            }
            bool needDecode = (interlaceMethod == 1) || (bitDepth == 16) || ((colorType & 4) != 0) || palShades || genBWMask;
            switch (colorType) {
                case 0:
                    inputBands = 1;
                    break;
                case 2:
                    inputBands = 3;
                    break;
                case 3:
                    inputBands = 1;
                    break;
                case 4:
                    inputBands = 2;
                    break;
                case 6:
                    inputBands = 4;
                    break;
            }
            if (needDecode)
                DecodeIdat();
            int components = inputBands;
            if ((colorType & 4) != 0)
                --components;
            int bpc = bitDepth;
            if (bpc == 16)
                bpc = 8;
            Image img;
            if (image != null) {
                if (colorType == 3)
                    img = new ImgRaw(width, height, components, bpc, image);
                else
                    img = Image.GetInstance(width, height, components, bpc, image);
            }
            else {
                img = new ImgRaw(width, height, components, bpc, idat.ToArray());
                img.Deflated = true;
                PdfDictionary decodeparms = new PdfDictionary();
                decodeparms.Put(PdfName.BITSPERCOMPONENT, new PdfNumber(bitDepth));
                decodeparms.Put(PdfName.PREDICTOR, new PdfNumber(15));
                decodeparms.Put(PdfName.COLUMNS, new PdfNumber(width));
                decodeparms.Put(PdfName.COLORS, new PdfNumber((colorType == 3 || (colorType & 2) == 0) ? 1 : 3));
                additional.Put(PdfName.DECODEPARMS, decodeparms);
            }
            if (additional.Get(PdfName.COLORSPACE) == null)
                additional.Put(PdfName.COLORSPACE, GetColorspace());
            if (intent != null)
                additional.Put(PdfName.INTENT, intent);
            if (additional.Size > 0)
                img.Additional = additional;
            if (icc_profile != null)
                img.TagICC = icc_profile;
            if (palShades) {
                Image im2 = Image.GetInstance(width, height, 1, 8, smask);
                im2.MakeMask();
                img.ImageMask = im2;
            }
            if (genBWMask) {
                Image im2 = Image.GetInstance(width, height, 1, 1, smask);
                im2.MakeMask();
                img.ImageMask = im2;
            }
            img.SetDpi(dpiX, dpiY);
            img.XYRatio = XYRatio;
            img.OriginalType = Image.ORIGINAL_PNG;
            return img;
        }

 /** Reads a PNG from a stream.
 * @param is the stream
 * @throws IOException on error
 * @return the image
 */
 public static Image GetImage(Stream isp)
 {
     PngImage png = new PngImage(isp);
     return png.GetImage();
 }