Parent Topic: DCP

LUT COMMANDS

General Lookup Table Command Syntax: DCP> L? n1,n2 ...

where ? is replaced by the particular command.

If n1=0, the command is performed on all lookup tables. This default is represented in the parameter description as <all>.

LOOKUP TABLE COMMANDS AVAILABLE: 

 LC:LUT Square Root   LD:LUT Display     LE:LUT Equalize
 LI:LUT Infrequency   LL:LUT Listing     LS:LUT Linear Stretch
 LW:LUT Write         LX:LUT Transfer    LZ:LUT Initialize

LC

LUT Square Root performs lookup table contrast stretching with a power function. 

 LC [n1,n2,...,n15]

 n1:      Lookup table to change              <all>
 n2:      100 times power to use              <50>
          Examples: n2= 50: square root
                       100: linear stretch
                       200: squaring
 n3:      Min. input                          <min. over image>
 n4:      Max. input                          <max. over image>
 n5:      Min. output                         <0>
 n6:      Max. output                         <255>
 n7:      Low end control (for when X < n3)   <0>
                 0:  F(X) = n5
                 1:  F(X) = n6
                 2:  leave F(X) alone
 n8:      High end control (for when X > n4)  <0>
                 0:  F(X) = n6
                 1:  F(X) = n5
                 2:  leave F(X) alone
 n9:      Graphic mask for sampling min. and  <entire image>
          max. input values
 n10,n11: Window offset for sampling min.     <0,0>
          and max. input values 
 n12,n13: Window size for sampling min. and   <rest of image>
          max. input values
 n14,n15: Percentage left and right trim for  <2,2>
          sampling min. and max. input values

                -1:  equal 0 (no trim)
Lookup table n1 is modified with the following power function: 

     F(X) = A*(X-n3)**P + n
where: 

         n3 <= X <= n4
         P = n2/100
         A is a scaling factor calculated such that
         F(n3) = n5,  and  F(n4) = n6.
If n5 < n6, then F(X) is monotonically increasing. If n5 > n6, then F(X) is monotonically decreasing.

If the user types LC with no parameters, a square root enhancement is performed on all lookup tables.

LD

LUT Display displays a lookup table on a graphic plane.

LD [n1,n2,n3,n4,n5,n6,n7,n8,n9] 

 n1:      Lookup table to display             <all>
 n2:      Graphic to draw on                  <n1>
 n3:      Draw grid on graphic plane          <0>
               0:  draw grid
               1:  do not draw grid
 n4:      Preclear graphic plane              <0>
               0:  preclear
               1:  do not preclear
 n5,n6:   Plot window offset                  <1/4 display size>
          If n1 is explicitly specified,
          then n5,n6 default to n1/8 display size.
 n7,n8:   Plot window size                    <1/2 display size>
          If n7,n8 are explicitly specified,
          then n5,n6 default to 0,0
 n9:      Labelling:  1: yes, 2: no.          <1>
          Labelling occurs only if there is
          enough room around the plot window
          to write the labels.

LE

LUT Equalize performs histogram equalization of the lookup table. 

 LE [n1,n2,...,n11]

 n1:      Lookup table to be equalized        <all>
 n2:      Smoothing factor for histogramming  <no smoothing>
 n3:      Min. output value                   <0>
 n4:      Max. output value                   <255>
 n5:      Graphic mask for sampling           <entire image>
 n6,n7:   Window offset for sampling          <0,0>
 n8,n9:   Window size for sampling            <rest of image>
 n10,n11: Percentage left and right trim      <no trim>
          for sampling

LI

LUT Infrequency performs histogram inversion of the lookup table (infrequency brightener). 

 LI [n1,n2,...,n11]

 n1:      Lookup table to be inverted         <all>
 n2:      Smoothing factor for histogramming  <no smoothing>
 n3:      Min. output value                   <0>
 n4:      Max. output value                   <255>
 n5:      Graphic mask for sampling           <entire image>
 n6,n7:   Window offset for sampling          <0,0>
 n8,n9:   Window size for sampling            <rest of image>
 n10,n11: Percentage left and right trim      <no trim>
          for sampling

LL

LUT Listing performs a Lookup Table Listing of output grey level values for each input grey level value. 

 LL [n1]

 n1:     Lookup table to be listed           <all>

LS

LUT Linear Stretch performs lookup table contrast stretching with a power function.

The LS command is identical to the LC command, except that n2 defaults to 100 (for linear stretch) instead of 50 (for square root stretch). Refer to the documentation for the LC command for details.

LW

LUT Write interactively writes/modifies the lookup table by using the display cursor. 

 LW n1[,n2,n3,n4,n5,n6,n7]

 n1:      Lookup table to be modified         <>
 n2:      Graphic plane to use for tracing    <n1>
 n3,n4:   Plot window offset                  <n1/8 display size>
 n5,n6:   Plot window size                    <1/2 display size>
          If n5,n6 are explicitly specified,
          then n3,n4 default to 0,0
 n7:      Labelling:  1: yes, 2: no.          <1>
          Labelling occurs only if there is
          enough room around the plot window
          to write the labels.
The user is repeatedly prompted as follows: 

 [P]in and track [U]ndo [R]elease [S]tart over e[X]it: 

 P:  Pin a new point on lookup table; start tracking session.
 U:  Undo changes to lookup table since last P command.
 R:  Release cursor; move it without affecting lookup table.
 S:  Start over; draw original lookup table.
 X:  eXit command; return to DCP.

LX

LUT Transfer transfers one lookup table to another. 

 LX n1,n2

 n1:      Destination lookup table             <>
 n2:      Source lookup table                  <>

LZ

LUT Initialize initializes the lookup table to a linear ramp (useful for showing `raw' data, unmodified by any values in the lookup table). 

 LZ [n1]

 n1:      Lookup table to be initialized       <all>
Parent Topic: DCP
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