mediaLib Library Functions                mlibImageLookUp(3MLIB)



NAME
     mlibImageLookUp - table lookup

SYNOPSIS
     cc [ flag... ] file... -lmlib [ library... ]
     #include 

     mlibstatus mlibImageLookUp(mlibimage *dst, const mlibimage *src,
          const void **table);


DESCRIPTION
     The mlibImageLookUp() function maps the source image to the
     destination image by using the user-specified lookup table.


     The source and destination images must have the  same  width
     and  height.  The source image can be a single channel image
     or can have the same number of channels as  the  destination
     image. One of the following equations is used accordingly:

       dst[x][y][i] = table[i][src[x][y][0]
       dst[x][y][i] = table[i][src[x][y][i]



     The source and destination images can  have  different  data
     types.  See  the following table for available variations of
     the table lookup function on image types:



        Type [*]      BYTE   SHORT       USHORT            INT        FLOAT       DOUBLE
     
     MLIBIT         Y
     MLIBYTE        Y      Y       Y                Y               Y       Y
     
     MLIBSHORT       Y      Y       Y                Y               Y       Y
     
     MLIBUSHORT      Y      Y       Y                Y               Y       Y
     
     MLIBINT         Y      Y       Y                Y               Y       Y



     [*] Each row represents a  source  data  type.  Each  column
     represents a destination data type.

PARAMETERS
     The function takes the following arguments:





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mediaLib Library Functions                mlibImageLookUp(3MLIB)



     dst      Pointer to destination image.


     src      Pointer to source image.


     table    Pointer to lookup  table.  The  data  type  of  the
              lookup  table is the same as the destination image.
              The number of entries in the lookup table is deter-
              mined by the type of the input image. The format of
              the lookup table is:

              table[channel][index]

              The MLIBIT type entries are indexed from 0 to  1.
              The  MLIBYTE  type  entries are indexed from 0 to
              255. The MLIBSHORT type entries are  indexed  from
              -32768 to -1, then from 0 to 32767. The MLIBUSHORT
              type entries are  indexed  from  0  to  65535.  The
              MLIBINT  type entries are indexed from -2147483648
              to -1, and then from 0 to 2147483647.

              If a table covering the full range  of  input  data
              type  is  not  available or not realistic, which is
              mostly true for doing table lookup with an MLIBINT
              input  image, a smaller table can be used.  In this
              case, the pointer to the table has to  be  adjusted
              as  if  it is pointing to the element for the smal-
              lest value of the input data type.  For example, to
              use  a  table covering input data range of [-65536,
              65535], the pointer needs to be  adjusted  as  fol-
              lows:

              table1632[0] ]= MLIBS32MIN ] 65536;

              This might cause a pointer arithmetic  overflow  in
              32-bit  mode, but probably works if the overflow is
              handled as a wrap-around.   If  possible,  function
              mlibImageLookUp2() should be used instead.


RETURN VALUES
     The function returns MLIBSUCES if  successful.  Otherwise
     it returns MLIBFAILURE.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:







SunOS 5.11          Last change: 12 Sep 2007                    2






mediaLib Library Functions                mlibImageLookUp(3MLIB)



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     mlibImageLookUpInp(3MLIB),       mlibImageLookUp2(3MLIB),
     mlibImageLookUpMask(3MLIB), attributes(5)











































SunOS 5.11          Last change: 12 Sep 2007                    3