LUTREAD

Read LUT from text file


EnvironmentsPYTHON :: EASI :: MODELER
Quick linksDescription :: Parameters :: Parameter descriptions :: Details :: Example :: Related

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Description


LUTREAD reads lookup table (LUT) data from a text file and writes it to an LUT segment (LUT type 170 or BLUT type 172) in a PCIDSK file.
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Parameters


Name Type Caption Length Value range
FILE* String Output file name 1 - 192  
DBLUT Integer Lookup table segment 0 - 1  
DBSN String Output LUT segment name 0 - 8 Default: LUTREAD
DBSD String Output LUT segment description 0 - 64  
LUTFORM String LUT text format 0 - 5 ATT, INOUT, OUT
Default: ATT
TFILE* String Text file 1 - 192  

* Required parameter
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Parameter descriptions

FILE

Specifies the name of the PCIDSK file to which the lookup table is written.

DBLUT

Specifies the segment that contains the lookup table (LUT type 170 or BLUT type 172). If this parameter is not specified, a new LUT segment is created.

DBSN

Specifies a name (up to 8 characters) for the output LUT segment. This string is displayed by ASL, and can be changed using MAS.

This parameter is required only if a new segment is created. If a name is not specified, the default name "LUTREAD" is assigned.

DBSD

Describes (in up to 64 characters) the contents or origins of the output segment.

This string is displayed by ASL if the LTYP parameter is set to SHORT or FULL, and can be changed using MAS.

The specified segment description can be used only if a new segment is created.

LUTFORM

Specifies the input text file format for the lookup table data. Valid values are:

TFILE

Specifies the name of the input text file from which the lookup table data is read.

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Details

LUTREAD transfers lookup table (LUT) data from a specified text file to a lookup table segment (LUT type 170 or BLUT type 172) in a PCIDSK file, assuming a given text file format.

Three LUT formats are available. See the LUTFORM (LUT Text Form) parameter details for more information.

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, output values for any missing entries default to 0. If an existing segment was specified, only the table entries that are read in are modified.
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Example

Read the lookup table from the text file negative.txt, which stores a lookup table for a negative image, where white becomes black, and black becomes white. Only output values are stored in this text file, show below:

 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

Use LUTREAD to read the text file into a new lookup table segment. You can then use LUTREP to view the segment that was created.

EASI>FILE	=	"irvine.pix"
EASI>DBLUT	=
EASI>DBSN	=	"NEGATIVE"
EASI>DBSD	=	"Negative lookup table"
EASI>LUTFORM	=	"OUT"
EASI>TFILE	=	"negative.txt"

EASI>RUN LUTREAD

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