public final class InterpType
extends org.freedesktop.bindings.Constant
scale()
method. In
general use it is recommended that you use the BILINEAR
algorithm.
The details of the implementations of the interpolation techniques made available here are obviously highly technical, and so are adapted directly from the gdkpixbuf library's documentation.
Modifier and Type  Field and Description 

static InterpType 
BILINEAR
Use the bilinear interpolation method.

static InterpType 
HYPER
A hyperbolic filtering algorithm.

static InterpType 
NEAREST
Interpolate by "nearest neighbour" sampling.

static InterpType 
TILES
Each pixel is rendered as a tiny parallelogram of solid color, the
edges of which are implemented with antialiasing.

public static final InterpType BILINEAR
public static final InterpType HYPER
The filter is idempotent for 1:1 pixel mapping.
According to the GDK documentation, this algorithm is formally defined as the "hyperbolicfilter sampling the ideal hyperbolicfilter interpolated image". Good thing they let us know that.
public static final InterpType NEAREST
public static final InterpType TILES
NEAREST
if scaling up, and to BILINEAR
if scaling down.
This is supposedly an accurate simulation of the PostScript's image operator (without any interpolation enabled).