mlib_ImageComposite(3MLIB)mediaLib Library Functionsmlib_ImageComposite(3MLIB)NAMEmlib_ImageComposite - image composition
SYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>
mlib_status mlib_ImageComposite(mlib_image *dst, const mlib_image *src1,
const mlib_image *src2, mlib_blend bsrc1, mlib_blend bsrc2,
mlib_s32 cmask);
DESCRIPTION
The mlib_ImageComposite() function supports digital image composition.
It is a wrapper of the mlib_ImageBlend_BSCR1_BSRC2 group of functions
and can perform various types of composition based on the parameters
passed in, whereas each function in that group can perform only the one
kind of composition denoted by its name.
The image type must be MLIB_BYTE. The input and output images must con‐
tain three or four channels. For three-channel images, the alpha value
is as if the alpha value is 1.
The following are predefined blend factor types used in mediaLib image
composition functions.
/* image blend factors */
typedef enum {
MLIB_BLEND_ZERO,
MLIB_BLEND_ONE,
MLIB_BLEND_DST_COLOR,
MLIB_BLEND_SRC_COLOR,
MLIB_BLEND_ONE_MINUS_DST_COLOR,
MLIB_BLEND_ONE_MINUS_SRC_COLOR,
MLIB_BLEND_DST_ALPHA,
MLIB_BLEND_SRC_ALPHA,
MLIB_BLEND_ONE_MINUS_DST_ALPHA,
MLIB_BLEND_ONE_MINUS_SRC_ALPHA,
MLIB_BLEND_SRC_ALPHA_SATURATE
} mlib_blend;
See the following table for the definitions of the blend factors.
Type Blend Factor [*] Abbr.
───────────────────────────────────────────────────────────────────
MLIB_BLEND_ZERO (0,0,0,0) ZERO
MLIB_BLEND_ONE (1,1,1,1) ONE
MLIB_BLEND_DST_COLOR (Rd,Gd,Bd,Ad) DC
MLIB_BLEND_SRC_COLOR (Rs,Gs,Bs,As) SC
MLIB_BLEND_ONE_MINUS_DST_COLOR (1,1,1,1)-(Rd,Gd,Bd,Ad) OMDC
MLIB_BLEND_ONE_MINUS_SRC_COLOR (1,1,1,1)-(Rs,Gs,Bs,As) OMSC
MLIB_BLEND_DST_ALPHA (Ad,Ad,Ad,Ad) DA
MLIB_BLEND_SRC_ALPHA (As,As,As,As) SA
MLIB_BLEND_ONE_MINUS_DST_ALPHA (1,1,1,1)-(Ad,Ad,Ad,Ad) OMDA
MLIB_BLEND_ONE_MINUS_SRC_ALPHA (1,1,1,1)-(As,As,As,As) OMSA
MLIB_BLEND_SRC_ALPHA_SATURATE (f,f,f,1) SAS
[*]: The components of the first source image pixel are (Rd,Gd,Bd,Ad),
and the components of the second source pixel are (Rs,Gs,Bs,As). Func‐
tion f = min(As, 1-Ad).
The blending formula for non-in-place processing is:
Cd = Cs1*S1 + Cs2*S2
where Cd is the destination pixel (Rd,Gd,Bd,Ad), Cs1 is the first
source pixel (Rs1,Gs1,Bs1,As1), Cs2 is the second source pixel
(Rs2,Gs2,Bs2,As2), and S1 and S2 are the blend factors for the first
and second sources, respectively.
PARAMETERS
The function takes the following arguments:
dst Pointer to destination image.
src1 Pointer to the first source image.
src2 Pointer to the second source image.
bsrc1 Blend factor type for the first source image.
bsrc2 Blend factor type for the second source image.
cmask Channel mask to indicate the alpha channel. Each bit of the
mask represents a channel in the image. The channel corre‐
sponding to the 1 bit is the alpha channel. cmask must be
either 0x01 or 0x08.
RETURN VALUES
The function returns MLIB_SUCCESS if successful. Otherwise it returns
MLIB_FAILURE.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOmlib_ImageBlend_BSRC1_BSRC2(3MLIB), mlib_Image‐
Blend_BSRC1_BSRC2_Inp(3MLIB), mlib_ImageComposite_Inp(3MLIB),
attributes(5)SunOS 5.10 2 Mar 2007 mlib_ImageComposite(3MLIB)
