LUTREAD -- Read LUT from Text File


<HEAD><TITLE>LUTREAD -- Read LUT from Text File</TITLE></HEAD>


<H1>LUTREAD -- Read LUT from Text File</H1>
Reads lookup table data from a text file and writes it to a lookup
table segment (LUT type 170) on a database file.
<P>

See Also: <A HREF = "http://www.pcigeomatics.com/cgi-bin/pcihlp/LUTWRIT">LUTWRIT</A>, <A HREF = "http://www.pcigeomatics.com/cgi-bin/pcihlp/PCTREAD">PCTREAD</A><P>
<H3>PARAMETERS</H3>
LUTREAD is controlled by the following global parameters:
<P>
<pre>Name     Prompt                                  Count     Type
FILE     Database File Name                      1-64      Char
DBLUT    Database Lookup Table                   0-1       Int
DBSN     Database Segment Name                   0-8       Char
DBSD     Database Segment Description            0-64      Char
LUTFORM  LUT Text Form: ATT/INOUT/OUT            3-5       Char
TFILE    Text File                               1-64      Char

The following parameter receives output:

LASC     Last Segment Created                    0-1       Int
</pre>
<H4>FILE</H4>
Specifies the name of the PCIDSK file to which the LUT is written.
<P>
<PRE>
 EASI&gt;FILE=&quot;filespec&quot;
</PRE>
<H4>DBLUT</H4>
Specifies the database segment that contains the lookup table (type
170).
<P>
<PRE>
 EASI&gt;DBLUT=i
 EASI&gt;DBLUT=                    | create new LUT segment
</PRE>
<H4>TFILE</H4>
<PRE>
  Valid Values:   &lt;filename, max. 64 characters&gt;
  Default:        &lt;none&gt;
</PRE>
Specifies the name of the input text file, from which the lookup
table data is read.
<P>
<H4>LUTFORM</H4>
<PRE>
  Valid Values:   ATT, INOUT, OUT
  Default:        ATT
</PRE>
Specifies the input text file format for the lookup table data.
<P>
<PRE>
 ATT    | attribute format    (range outvalue)
 INOUT  | input/output format (invalue outvalue)
 OUT    | output format       (outvalue)
</PRE>
<H4>DBSN</H4>
<PRE>
  Valid Values:   &lt;string, max. 8 characters&gt;
  Default:        LUTREAD
</PRE>
Specifies an identifier that will be assigned to the new output
lookup table segment. This string is displayed by ASL, and may be
changed using MAS.<p>
DBSN is only required if a new segment is created.
<P>
<H4>DBSD</H4>
<PRE>
  Valid Values:   &lt;string, max. 64 characters&gt;
  Default:        &lt;none&gt;
</PRE>
Optionally specifies a character descriptor that will be associated
with the new output segment (string describing contents of origin of
data).<p>
This string is displayed by ASL if LTYP = &quot;SHORT&quot; or &quot;FULL&quot;, and
may be changed using MAS.<p>
DBSD may only be used if a new segment is created.
<P>
<H4>LASC</H4>
If a new segment is created, then LASC is assigned the number for
the new segment, after the program has finished executing.
<P>
<H3>DETAILS</H3>
LUTREAD transfers lookup data from a specified text file (TFILE) to
a lookup table segment (DBLUT) on a database (FILE), assuming a
given text file format (LUTFORM).<p>
There are three formats (LUTFORM) available:
<P>
<UL>
<LI> Attribute format (LUTFORM= &quot;ATT&quot;) uses PCI's attribute data
format for storing the lookup table. See the Attribute Data
chapter in the `Using PCI Software' manual for details on the
attribute data format. The general form for a line of text is as
follows: 
</UL>
<PRE>
          start : end ; output ; comment

    example: 
              0 :   2 ; 255    ; white
</PRE>
<UL>
<LI> Input/output format (LUTFORM=&quot;INOUT&quot;) list both an input value
and an output value for each table entry. The general form for a
line of text is as follows: 
</UL>
<PRE>
          input  output   input  output   input  output ...

    example:
           0     255       1     255       2     255
</PRE>
<UL>
<LI> Output format (LUTFORM=&quot;OUT&quot;) lists only the output value for
each table entry. The general form for a line of text is: 
</UL>
<PRE>
            output  output  output ...

    example:
             255     255     255
</PRE>
Note: It is not essential that all 256 entries in a lookup table be
specified in the text file. If a new segment is created, then output
values for any missing entries default to 0. If an existing segment
was specified, then only the table entries which are read in are
modified.
<P>
<H3>EXAMPLE</H3>
Read the lookup table from the text file negative.txt, which stores
a lookup table for a negative image, where white becomes black, and
where black becomes white. Only output values are stored in this
text file, show below:
<P>
<PRE>
 255 254 253 252 251 250 249 248 247 246 245 244 243 242 241 240
 239 238 237 236 235 234 233 232 231 230 229 228 227 226 225 224
 223 222 221 220 219 218 217 216 215 214 213 212 211 210 209 208
 207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192
 191 190 189 188 187 186 185 184 183 182 181 180 179 178 177 176
 175 174 173 172 171 170 169 168 167 166 165 164 163 162 161 160
 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144
 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128
 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112
 111 110 109 108 107 106 105 104 103 102 101 100  99  98  97  96
  95  94  93  92  91  90  89  88  87  86  85  84  83  82  81  80
  79  78  77  76  75  74  73  72  71  70  69  68  67  66  65  64
  63  62  61  60  59  58  57  56  55  54  53  52  51  50  49  48
  47  46  45  44  43  42  41  40  39  38  37  36  35  34  33  32
  31  30  29  28  27  26  25  24  23  22  21  20  19  18  17  16
  15  14  13  12  11  10   9   8   7   6   5   4   3   2   1   0
</PRE>
Read the text file into a new lookup table segment.
<P>
<PRE>
 EASI&gt;FILE=&quot;local.pix&quot;
 EASI&gt;DBLUT=
 EASI&gt;LUTFORM=&quot;OUT&quot;
 EASI&gt;DBSN=&quot;NEGATIVE&quot;
 EASI&gt;DBSD=&quot;Negative lookup table&quot;
 EASI&gt;TFILE=&quot;negative.txt&quot;
 EASI&gt;RUN LUTREAD
</PRE>
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