mlib_ImageComposite_Inp

- image composition, in place

Synopsis

cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>

mlib_status mlib_ImageComposite_Inp(mlib_image *src1dst,
     const mlib_image *src2, mlib_blend bsrc1, mlib_blend bsrc2,
     mlib_s32 cmask);

Description

The mlib_ImageComposite_Inp() function supports digital image composition.

It is a wrapper of the mlib_ImageBlend_BSCR1_BSRC2_Inp group of functions and can perform various types of composition based on the parameters passed in, whereas each function in the mlib_ImageBlend_BSCR1_BSRC2_Inp 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 contain 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.

[*]: 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). Function f = min(As, 1-Ad). The first source image is also the destination image.

The blending formula for in-place processing is:

Cd = Cd*D + Cs*S

where Cd is the destination pixel (Rd,Gd,Bd,Ad), Cs is the source pixel (Rs,Gs,Bs,As), and D and S are the blend factors for the destination and source, respectively.

Parameters

The function takes the following arguments:

src1dst

Pointer to the first source and the destination 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 corresponding 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:

See Also

mlib_ImageBlend_BSRC1_BSRC2(3MLIB), mlib_ImageBlend_BSRC1_BSRC2_Inp(3MLIB), mlib_ImageComposite(3MLIB), attributes(5)