private static void ComputeNormalizedModalityLut(IEnumerable <IFrameReference> frames, out double slope, out double intercept)
{
var rangeMin = double.MaxValue;
var rangeMax = double.MinValue;
foreach (var frameReference in frames)
{
var bitsStored = frameReference.Frame.BitsStored;
var isSigned = frameReference.Frame.PixelRepresentation != 0;
var rescaleSlope = frameReference.Frame.RescaleSlope;
var rescaleIntercept = frameReference.Frame.RescaleIntercept;
rangeMax = Math.Max(rangeMax, DicomPixelData.GetMaxPixelValue(bitsStored, isSigned) * rescaleSlope + rescaleIntercept);
rangeMin = Math.Min(rangeMin, DicomPixelData.GetMinPixelValue(bitsStored, isSigned) * rescaleSlope + rescaleIntercept);
}
intercept = rangeMin;
slope = (rangeMax - rangeMin) / 65535;
}
private static LutValueRange SyncMinMaxValues(IComposableLut[] luts, int bitsStored, bool isSigned)
{
var range = new LutValueRange();
luts[0].MinInputValue = range.MinInputValue = DicomPixelData.GetMinPixelValue(bitsStored, isSigned);
luts[0].MaxInputValue = range.MaxInputValue = DicomPixelData.GetMaxPixelValue(bitsStored, isSigned);
var lutCount = luts.Length;
for (var j = 1; j < lutCount; ++j)
{
luts[j].MinInputValue = luts[j - 1].MinOutputValue;
luts[j].MaxInputValue = luts[j - 1].MaxOutputValue;
}
range.MinOutputValue = (int)Math.Round(luts[lutCount - 1].MinOutputValue);
range.MaxOutputValue = (int)Math.Round(luts[lutCount - 1].MaxOutputValue);
return(range);
}
public void TestGetMinMaxPixelData()
{
Assert.AreEqual(0, DicomPixelData.GetMinPixelValue(7, false));
Assert.AreEqual(0, DicomPixelData.GetMinPixelValue(8, false));
Assert.AreEqual(0, DicomPixelData.GetMinPixelValue(12, false));
Assert.AreEqual(0, DicomPixelData.GetMinPixelValue(16, false));
Assert.AreEqual(127, DicomPixelData.GetMaxPixelValue(7, false));
Assert.AreEqual(255, DicomPixelData.GetMaxPixelValue(8, false));
Assert.AreEqual(4095, DicomPixelData.GetMaxPixelValue(12, false));
Assert.AreEqual(65535, DicomPixelData.GetMaxPixelValue(16, false));
Assert.AreEqual(-64, DicomPixelData.GetMinPixelValue(7, true));
Assert.AreEqual(-128, DicomPixelData.GetMinPixelValue(8, true));
Assert.AreEqual(-2048, DicomPixelData.GetMinPixelValue(12, true));
Assert.AreEqual(-32768, DicomPixelData.GetMinPixelValue(16, true));
Assert.AreEqual(63, DicomPixelData.GetMaxPixelValue(7, true));
Assert.AreEqual(127, DicomPixelData.GetMaxPixelValue(8, true));
Assert.AreEqual(2047, DicomPixelData.GetMaxPixelValue(12, true));
Assert.AreEqual(32767, DicomPixelData.GetMaxPixelValue(16, true));
}
internal static VolumeHeaderData TestCreate(IList <IDicomAttributeProvider> sourceSops, int bitsAllocated = 16, int bitsStored = 16, bool isSigned = false, string laterality = null)
{
return(new VolumeHeaderData(sourceSops, new Size3D(0, 0, 0), new Vector3D(0, 0, 0), new Vector3D(0, 0, 0), new Matrix3D(), bitsAllocated, bitsStored, isSigned, DicomPixelData.GetMinPixelValue(bitsAllocated, isSigned), 1, 0, null, laterality));
}
internal IdentityVoiLinearLut(int bitsStored, bool signed)
{
MinInputValue = DicomPixelData.GetMinPixelValue(bitsStored, signed);
MaxInputValue = DicomPixelData.GetMaxPixelValue(bitsStored, signed);
}
/// <summary>
/// Computes a pixel value suitable for volume padding purposes.
/// </summary>
/// <remarks>
/// This function will try to use the value of either <see cref="DicomTags.PixelPaddingValue"/>,
/// <see cref="DicomTags.SmallestPixelValueInSeries"/> or <see cref="DicomTags.SmallestImagePixelValue"/>
/// (in order of preference). If none of these attributes exist in the dataset, then a suitable value is
/// computed based on <see cref="DicomTags.BitsStored"/>, <see cref="DicomTags.PixelRepresentation"/>,
/// and <see cref="DicomTags.PhotometricInterpretation"/>.
/// </remarks>
private static ushort ComputePixelPaddingValue(IList <IFrameReference> frames, double normalizedSlope, double normalizedIntercept)
{
var isSigned = frames[0].Frame.PixelRepresentation != 0;
var isMonochrome1 = frames[0].Frame.PhotometricInterpretation.Equals(PhotometricInterpretation.Monochrome1);
var bitsStored = Math.Max(1, Math.Min(16, frames[0].Frame.BitsStored));
var pixelPaddingValue = isMonochrome1 ? DicomPixelData.GetMaxPixelValue(bitsStored, isSigned) : DicomPixelData.GetMinPixelValue(bitsStored, isSigned);
DicomAttribute attribute;
var frameAttributeProvider = (IDicomAttributeProvider)frames[0].Frame;
if (frameAttributeProvider.TryGetAttribute(DicomTags.PixelPaddingValue, out attribute))
{
pixelPaddingValue = attribute.GetInt32(0, pixelPaddingValue);
}
else if (frameAttributeProvider.TryGetAttribute(DicomTags.SmallestPixelValueInSeries, out attribute))
{
pixelPaddingValue = attribute.GetInt32(0, pixelPaddingValue);
}
else if (frameAttributeProvider.TryGetAttribute(DicomTags.SmallestImagePixelValue, out attribute))
{
pixelPaddingValue = attribute.GetInt32(0, pixelPaddingValue);
}
// these next few lines may look positively stupid, but they are here for a good reason (See Ticket #7026)
if (isSigned)
{
pixelPaddingValue = (short)pixelPaddingValue;
}
else
{
pixelPaddingValue = (ushort)pixelPaddingValue;
}
// since the volume now stores values with original modality LUT and normalizing function applied, we must apply same to this value (#9417)
var rescaledPaddingValue = frames[0].Frame.RescaleSlope * pixelPaddingValue + frames[0].Frame.RescaleIntercept;
var normalizedPaddingValue = (rescaledPaddingValue - normalizedIntercept) / normalizedSlope;
return((ushort)Math.Max(ushort.MinValue, Math.Min(ushort.MaxValue, Math.Round(normalizedPaddingValue))));
}
