Function

VipsImagecomposite

Declaration [src] 

int
vips_composite (
  VipsImage** in,
  VipsImage** out,
  int n,
  int* mode,
  ...
)

Description [src]

Composite an array of images together.

Images are placed in a stack, with in[0] at the bottom and in[n - 1] at the top. Pixels are blended together working from the bottom upwards, with the blend mode at each step being set by the corresponding VipsBlendMode in mode.

Images are transformed to a compositing space before processing. This is VIPS_INTERPRETATION_sRGB, VIPS_INTERPRETATION_B_W, VIPS_INTERPRETATION_RGB16, or VIPS_INTERPRETATION_GREY16 by default, depending on how many bands and bits the input images have. You can select any other space, such as VIPS_INTERPRETATION_LAB or VIPS_INTERPRETATION_scRGB.

The output image is in the compositing space. It will always be VIPS_FORMAT_FLOAT unless one of the inputs is VIPS_FORMAT_DOUBLE, in which case the output will be double as well.

Complex images are not supported.

The output image will always have an alpha band. A solid alpha is added to any input missing an alpha.

The images do not need to match in size or format. The output image is always the size of in[0], with other images being positioned with the x and y parameters and clipped against that rectangle.

Image are normally treated as unpremultiplied, so this operation can be used directly on PNG images. If your images have been through vips_premultiply(), set premultiplied.

Optional arguments

  • compositing_space: VipsInterpretation to composite in
  • premultiplied: gboolean, images are already premultiplied
  • x: VipsArrayInt, array of (n - 1) x coordinates
  • y: VipsArrayInt, array of (n - 1) y coordinates

See also

vips_insert().

This function is not directly available to language bindings.

Parameters

in

Type: An array of VipsImage*

Array of input images.

The length of the array is specified in the n argument.
The data is owned by the caller of the function.
out

Type: VipsImage

Output image.

The argument will be set by the function.
The caller of the function takes ownership of the returned data, and is responsible for freeing it.
n

Type: int

Number of input images.

mode

Type: int*

Array of (n - 1) VipsBlendMode.

The data is owned by the caller of the function.
...

Type: 

NULL-terminated list of optional named arguments.

Return value

Type: int

0 on success, -1 on error.