Vips.Image.tilecache (original) (raw)

Method

Vips Imagetilecache

Declaration [src]


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

Description [src]

This operation behaves rather like vips_copy() between imagesin and out, except that it keeps a cache of computed pixels. This cache is made of up to max_tiles tiles (a value of -1 means any number of tiles), and each tile is of size tile_widthby tile_height pixels.

Each cache tile is made with a single call tovips_region_prepare().

When the cache fills, a tile is chosen for reuse. If access isVIPS_ACCESS_RANDOM, then the least-recently-used tile is reused. Ifaccess is VIPS_ACCESS_SEQUENTIALthe top-most tile is reused.

By default, tile_width and tile_height are 128 pixels, and the operation will cache up to 1,000 tiles. access defaults to VIPS_ACCESS_RANDOM.

Normally, only a single thread at once is allowed to calculate tiles. If you set threaded to TRUE, vips_tilecache() will allow many threads to calculate tiles at once, and share the cache between them.

Normally the cache is dropped when computation finishes. Set persistent toTRUE to keep the cache between computations.

Optional arguments

tile_width: gint, width of tiles in cache
tile_height: gint, height of tiles in cache
max_tiles: gint, maximum number of tiles to cache
access: VipsAccess, hint expected access pattern
threaded: gboolean, allow many threads
persistent: gboolean, don’t drop cache at end of computation

This method is not directly available to language bindings.

Parameters

out

Type: VipsImage

Output image.

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

...

Type: ``

NULL-terminated list of optional named arguments.

Return value

Type: int

0 on success, -1 on error.

Vips.Image.tilecache (original) (raw)

Method