TIOParams.DICOM_RescaleSlope

Declaration

property DICOM_RescaleSlope: Double;

Description

Returns the value of the Rescale Slope tag (0028,1053).
Rescale Slope and DICOM_RescaleIntercept define a linear subset of a conceptual Modality LUT transformation.
Pixel values are adjusted when loading, so use DICOM_PixelToValue to get the original value of a pixel.

Note: When saving DICOM, if the pixel values were adjusted when loading (e.g. DICOM_Range = iedrAdjust), the DICOM_RescaleSlope and DICOM_RescaleIntercept tags are updated so that the adjusted pixel values map back to their original units (e.g. Hounsfield units). Values outside of the window range are clipped. Where this is not possible (e.g. color images) the tags are removed. If you have created the image in code, any Rescale tags you specify in DICOM_Tags are retained

Example

// Calculate the Hounsfield unit for a pixel
// https://en.wikipedia.org/wiki/Hounsfield_scale

// Load image
ImageEnView1.IO.NativePixelFormat := True;
ImageEnView1.IO.Params.DICOM_Range := iedrSetBlackWhite;
ImageEnView1.IO.LoadFromFileDICOM(...);

// Get Hounsfield unit
// Note: Do not calculate this as Pixel * DICOM_RescaleSlope + DICOM_RescaleIntercept, because pixel values are adjusted when loading
hu := ImageEnView1.IO.Params.DICOM_PixelToValue( ImageEnView1.IEBitmap.Pixels_ie16g[x, y] );

TIOParams.DICOM_RescaleSlope