1mlib_ImageDivAlpha_Inp(3MLImBe)diaLib Library Functiomnlsib_ImageDivAlpha_Inp(3MLIB)
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NAME

6       mlib_ImageDivAlpha_Inp - alpha channel division, in place
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SYNOPSIS

9       cc [ flag... ] file... -lmlib [ library... ]
10       #include <mlib.h>
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12       mlib_status mlib_ImageDivAlpha_Inp(mlib_image *srcdst, mlib_s32 cmask);
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DESCRIPTION

16       The  mlib_ImageDivAlpha_Inp()  function  divides  color channels by the
17       alpha channel on a pixel-by-pixel basis, in place.
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20       For the MLIB_BYTE image, it uses the following equation:
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22         srcdst[x][y][c] = srcdst[x][y][c] / (srcdst[x][y][a] * 2**(-8))
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26       For the MLIB_SHORT image, it uses the following equation:
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28         srcdst[x][y][c] = srcdst[x][y][c] / (srcdst[x][y][a] * 2**(-15))
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32       For the MLIB_USHORT image, it uses the following equation:
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34         srcdst[x][y][c] = srcdst[x][y][c] / (srcdst[x][y][a] * 2**(-16))
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38       For the MLIB_INT image, it uses the following equation:
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40         srcdst[x][y][c] = srcdst[x][y][c] / (srcdst[x][y][a] * 2**(-31))
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44       where c and a are the indices for the  color  channels  and  the  alpha
45       channel, respectively, so c != a.
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48       In the case of srcdst[x][y][a] = 0,
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50         srcdst[x][y][c] = 0              if srcdst[x][y][c] = 0
51         srcdst[x][y][c] = DATA_TYPE_MAX  if srcdst[x][y][c] > 0
52         srcdst[x][y][c] = DATA_TYPE_MIN  if srcdst[x][y][c] < 0
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56       where  DATA_TYPE  is  MLIB_U8,  MLIB_S16,  MLIB_U16, or MLIB_S32 for an
57       image of type MLIB_BYTE, MLIB_SHORT, MLIB_USHORT, or MLIB_INT,  respec‐
58       tively.
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PARAMETERS

61       The function takes the following arguments:
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63       srcdst    Pointer to source and destination image.
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66       cmask     Channel  mask  to indicate the alpha channel. Each bit of the
67                 mask represents a channel in the image.  The  channel  corre‐
68                 sponding to the 1 bit of cmask is the alpha channel.
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RETURN VALUES

72       The  function  returns MLIB_SUCCESS if successful. Otherwise it returns
73       MLIB_FAILURE.
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ATTRIBUTES

76       See attributes(5) for descriptions of the following attributes:
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81       ┌─────────────────────────────┬─────────────────────────────┐
82       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
83       ├─────────────────────────────┼─────────────────────────────┤
84       │Interface Stability          │Committed                    │
85       ├─────────────────────────────┼─────────────────────────────┤
86       │MT-Level                     │MT-Safe                      │
87       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

90       mlib_ImageDivAlpha(3MLIB), mlib_ImageDivAlpha_Fp(3MLIB),  mlib_ImageDi‐
91       vAlpha_Fp_Inp(3MLIB), attributes(5)
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95SunOS 5.11                        2 Mar 2007     mlib_ImageDivAlpha_Inp(3MLIB)
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