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--- jvs:fscan:manual:chapter2:expression:gradient [2011/09/19 00:01]
voyvodic
+++ jvs:fscan:manual:chapter2:expression:gradient [2023/02/23 18:43] (current)
@@ Line 1: / Line 1: @@
 **fScan Reference Manual, Chapter 2 (CmdLineOptions:Expr): Gradient**
 ===== Gradient -- =====
- **usage:  -expr gradient **\\
+ **usage:  -expr gradient -- create a local intensity gradient map **\\
+The GRADIENT function analyzes the local intensity gradient around each voxel and generates a gradient map in which each map value is a composite index of the intensity gradient along the X, Y, and Z axes.
+Each map value is a 16-bit integer with 3 5-bit fields, in the binary form:  ZZZZZYYYYYXXXXX\\
+Within each field, you should subtract 16 from the 5 bit value (0-31) to get the gradient value (-15 - +15).
+The gradient value indicates the average slope of the intensity gradient along that axis.
 **See Also:**\\
+[[jvs:fscan:manual:chapter2:expression:peak|Peak]]
 [[jvs:fscan|fScan Home]],
 [[jvs:fscan:manual|fScan Manual]],

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