Method

VipsImageflatten

Declaration [src]

int
vips_flatten (
  VipsImage* in,
  VipsImage** out,
  ...
)

Description [src]

Take the last band of in as an alpha and use it to blend the remaining channels with background.

The alpha channel is 0 - max_alpha, where max_alpha means 100% image and 0 means 100% background. background defaults to zero (black).

max_alpha has the default value 255, or 65535 for images tagged as VipsInterpretation or VipsInterpretation.

Useful for flattening PNG images to RGB.

Non-complex images only.

::: tip “Optional arguments” * background: VipsArrayDouble colour for new pixels * max_alpha: gdouble, maximum value for alpha

::: seealso vips_premultiply(), vips_pngload().

Parameters

out VipsImage
 

Output image.

 The argument will be set by the function.
 The instance takes ownership of the data, and is responsible for freeing it.
... none
 

NULL-terminated list of optional named arguments.

Return value

Returns: int
 

0 on success, -1 on error.