private static IVoiLut GetInitialVoiLut(IGraphic graphic)
{
GrayscaleImageGraphic grayImageGraphic = (GrayscaleImageGraphic) graphic;
IVoiLut lut = InitialVoiLutProvider.Instance.GetLut(graphic.ParentPresentationImage);
if (lut == null)
lut = new MinMaxPixelCalculatedLinearLut(grayImageGraphic.PixelData, grayImageGraphic.ModalityLut);
return lut;
}
/// <summary>
/// Gets the initial VOI LUT for the source frames (base or overlay). This is NOT the LUT used on the fusion image! See <see cref="InstallVoiLut"/>.
/// </summary>
private static IVoiLut GetInitialVoiLut(Frame frame)
{
if (frame != null)
{
using (var image = PresentationImageFactory.Create(frame))
{
var voiLut = InitialVoiLutProvider.Instance.GetLut(image);
if (voiLut == null && image is IImageGraphicProvider)
{
var pixelData = ((IImageGraphicProvider) image).ImageGraphic.PixelData;
if (pixelData is GrayscalePixelData)
voiLut = new MinMaxPixelCalculatedLinearLut((GrayscalePixelData) pixelData);
}
return voiLut;
}
}
return null;
}
private MinMaxPixelCalculatedLinearLut(MinMaxPixelCalculatedLinearLut source, ICloningContext context)
: base(source, context)
{
context.CloneFields(source, this);
}
/// <summary>
/// Attempts to install an appropriate equivalent of the specified <paramref name="sourceVoiLut"/> to a fusion image. If the LUT is not linear, computes a dummy LUT.
/// </summary>
private static void InstallVoiLut(FusionPresentationImage fusionImage, IVoiLut sourceVoiLut, Frame sourceFrame, bool applyToOverlay)
{
IVoiLut newVoiLut;
if (sourceVoiLut is MinMaxPixelCalculatedLinearLut)
{
if (applyToOverlay)
{
// if the overlay source image is using a min/max calculated LUT, install a custom calculated LUT that delay-computes min/max from the fusion data
// we need to delay-compute this because the fusion image graphic is delay-generated, and thus not necessarily available until just before rendering!
var skipModalityLut = sourceFrame.ParentImageSop.Modality == @"PT" && sourceFrame.IsSubnormalRescale;
newVoiLut = new FusionOverlayMinMaxVoiLutLinear(fusionImage, !skipModalityLut);
}
else
{
// if the base source image is using a min/max calculated LUT, install a similarly min/max calculated LUT for the base of the fusion image
newVoiLut = new MinMaxPixelCalculatedLinearLut(fusionImage.ImageGraphic.PixelData);
}
}
else if (sourceVoiLut is IVoiLutLinear)
{
var voiLutLinear = (IVoiLutLinear) sourceVoiLut;
var normalizedVoiSlope = 1.0;
var normalizedVoiIntercept = 0.0;
if (applyToOverlay && sourceFrame.ParentImageSop.Modality == @"PT" && sourceFrame.IsSubnormalRescale)
{
// for subnormal PET rescale slope cases, the original VOI windows must be transformed through the same process as what MPR did to the pixel data
normalizedVoiSlope = sourceFrame.RescaleSlope/fusionImage.OverlayFrameData.OverlayRescaleSlope;
normalizedVoiIntercept = (sourceFrame.RescaleIntercept - fusionImage.OverlayFrameData.OverlayRescaleIntercept)/fusionImage.OverlayFrameData.OverlayRescaleSlope;
}
newVoiLut = new BasicVoiLutLinear(voiLutLinear.WindowWidth*normalizedVoiSlope, voiLutLinear.WindowCenter*normalizedVoiSlope + normalizedVoiIntercept);
}
else
{
// if the source image is using some non-linear LUT, just install a default pass-through LUT
newVoiLut = new IdentityVoiLinearLut();
}
if (applyToOverlay)
fusionImage.OverlayVoiLutManager.InstallVoiLut(newVoiLut);
else
fusionImage.BaseVoiLutManager.InstallVoiLut(newVoiLut);
}
private MinMaxPixelCalculatedLinearLut(MinMaxPixelCalculatedLinearLut source, ICloningContext context)
: base(source, context)
{
context.CloneFields(source, this);
}