Function: toLowHighRange()
toLowHighRange(
windowWidth,windowCenter,voiLUTFunction):object
Given a window width and center, return the lower and upper bounds of the window. The calculation depends on the VOI LUT Function:
LINEAR (default):
- Uses the DICOM standard formula from C.11.2.1.2.1: if x {'<='} c - 0.5 - (w-1)/2 {'=>'} lower bound if x {'>'} c - 0.5 + (w-1)/2 {'=>'} upper bound
LINEAR_EXACT (C.11.2.1.3.2):
- Uses: lower = c - w/2 upper = c + w/2
SIGMOID (C.11.2.1.3.1):
- The sigmoid does not define linear "bounds" in the same way. It's asymptotic.
- We define approximate bounds by choosing output thresholds (e.g., 1% and 99%) and solving for input x: y = 1/(1 + exp(-4*(x - c)/w)) For y=0.01 and y=0.99, solve for x.
Parameters
• windowWidth: number
The width of the window
• windowCenter: number
The center of the window
• voiLUTFunction: VOILUTFunctionType = VOILUTFunctionType.LINEAR
'LINEAR' | 'LINEAR_EXACT' | 'SIGMOID'
Returns
object
An object containing the lower and upper bounds of the window
lower
lower:
number
upper
upper:
number