Function

Vipscomposite

Declaration [src] 

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

Description [src]

Optional arguments:

  • compositing_space: VipsInterpretation to composite in
  • premultiplied: %gboolean, images are already premultiplied
  • x: VipsArrayInt, position of subimages
  • y: VipsArrayInt, position of subimages

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. They will be expanded to the smallest common size and format in the usual way. Images are positioned using the x and y parameters, if set.

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.

See also: vips_insert().

This function is not directly available to language bindings

Parameters

in 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 VipsImage
 

Output image.
 The argument will be set by the function.
 The called function takes ownership of the data, and is responsible for freeing it.
n int
 

Number of input images.
mode int*
 

Array of (n - 1) VipsBlendMode.
 The data is owned by the caller of the function.
...
 

NULL-terminated list of optional named arguments.

Return value

Returns: int
 

0 on success, -1 on error.