Class
VipsRegion
Description [src]
class Vips.Region : Vips.Object {
parent_object: VipsObject,
im: VipsImage*,
valid: VipsRect
}A small part of a VipsImage. valid holds the left/top/width/height of the
area of pixels that are available from the region.
See also: VIPS_REGION_ADDR(), vips_region_new(), vips_region_prepare().
Constructors
vips_region_new
Create a region. VipsRegion s start out empty, you need to call
vips_region_prepare() to fill them with pixels.
Instance methods
vips_region_black
Paints 0 into the valid part of reg.
vips_region_buffer
The region is transformed so that at least r pixels are available as a
memory buffer that can be written to.
vips_region_copy
Copy from one region to another. Copy area r from inside reg to dest,
positioning the area of pixels at x, y. The two regions must have pixels
which are the same size.
vips_region_equalsregion
Do two regions point to the same piece of image? ie.
vips_region_fetch
Generate an area of pixels and return a copy. The result must be freed with g_free(). The requested area must be completely inside the image.
vips_region_height
vips_region_image
The region is transformed so that at least r pixels are available to be
read from the image. The image needs to be a memory buffer or represent a
file on disc that has been mapped or can be mapped.
vips_region_invalidate
Mark a region as containing invalid pixels. Calling this function means
that the next time vips_region_prepare() is called, the region will be recalculated.
vips_region_paint
Paints value into reg covering rectangle r.
r is clipped against
reg->valid.
vips_region_paint_pel
Paints ink into reg covering rectangle r. r is clipped against
reg->valid.
vips_region_position
Set the position of a region. This only affects reg->valid, ie. the way pixels are addressed, not reg->data, the pixels which are addressed. Clip against the size of the image. Do not allow negative positions, or positions outside the image.
vips_region_prepare
Vips_region_prepare() fills reg with pixels. After calling,
you can address at least the area r with VIPS_REGION_ADDR() and get
valid pixels.
vips_region_prepare_to
Like vips_region_prepare(): fill reg with the pixels in area r.
vips_region_region
Make VIPS_REGION_ADDR() on reg go to dest instead.
vips_region_shrink
Write the pixels target in to from the x2 larger area in from.
Non-complex uncoded images and LABQ only. Images with alpha (see
vips_image_hasalpha()) shrink with pixels scaled by alpha to avoid fringing.
vips_region_shrink_method
Write the pixels target in to from the x2 larger area in from.
Non-complex uncoded images and LABQ only. Images with alpha (see
vips_image_hasalpha()) shrink with pixels scaled by alpha to avoid fringing.
vips_region_width
Methods inherited from VipsObject (27)
Please see VipsObject for a full list of methods.
Properties
Properties inherited from VipsObject (2)
Signals
Signals inherited from VipsObject (4)
Vips.Object::close
The ::close signal is emitted once during object close. The object is dying and may not work.
Vips.Object::postbuild
The ::postbuild signal is emitted once just after successful object construction. Return non-zero to cause object construction to fail.
Vips.Object::postclose
The ::postclose signal is emitted once after object close. The object pointer is still valid, but nothing else.
Vips.Object::preclose
The ::preclose signal is emitted once just before object close starts. The oject is still alive.
Signals inherited from GObject (1)
GObject.Object::notify
The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.