Dicom.Data.DcmDataset.GetCS C# (CSharp) Method

        public DcmCodeString GetCS(DicomTag tag)
        {
            DcmElement elem = GetElement(tag);
            if (elem is DcmCodeString)
                return elem as DcmCodeString;
            if (elem != null)
                throw new DicomDataException("Tried to access element with incorrect VR");
            return null;
        }

		public void UpdateDataset(DcmDataset dataset) {
			if (_lossy) {
				DcmCodeString cs = dataset.GetCS(DicomTags.ImageType);
				if (cs != null) {
					string[] values = cs.GetValues();
					values[0] = "DERIVED";
					cs.SetValues(values);
				}

				dataset.AddElementWithValue(DicomTags.SOPInstanceUID, DicomUID.Generate());

				// FIXME: append existing values
				dataset.AddElementWithValue(DicomTags.LossyImageCompression, "01");
				dataset.AddElementWithValue(DicomTags.LossyImageCompressionMethod, _lossyMethod);
				dataset.AddElementWithValue(DicomTags.LossyImageCompressionRatio, _lossyRatio);
			}
			dataset.AddElementWithValue(DicomTags.NumberOfFrames, _frames);
			dataset.AddElementWithValue(DicomTags.Columns, _width);
			dataset.AddElementWithValue(DicomTags.Rows, _height);
			dataset.AddElementWithValue(DicomTags.HighBit, _highBit);
			dataset.AddElementWithValue(DicomTags.BitsStored, _bitsStored);
			dataset.AddElementWithValue(DicomTags.BitsAllocated, _bitsAllocated);
			dataset.AddElementWithValue(DicomTags.SamplesPerPixel, _samplesPerPixel);
			dataset.AddElementWithValue(DicomTags.PixelRepresentation, _pixelRepresentation);
			dataset.AddElementWithValue(DicomTags.PhotometricInterpretation, _photometricInterpretation);
			if (SamplesPerPixel == 1) {
				dataset.AddElementWithValue(DicomTags.RescaleSlope, _rescaleSlope);
				dataset.AddElementWithValue(DicomTags.RescaleIntercept, _rescaleIntercept);
				//if (_pixelPaddingValue != 0)
				//    dataset.AddElementWithValue(DicomTags.PixelPaddingValue, _pixelPaddingValue);
			}
			else {
				dataset.AddElementWithValue(DicomTags.PlanarConfiguration, _planarConfiguration);
			}
			dataset.AddItem(_pixelDataItem);
		}