Best quality/speed balance; use this mode by default. Bilinear interpolation. For enlargement, it is equivalent to point-sampling the ideal bilinear-interpolated image. For reduction, it is equivalent to laying down small tiles and integrating over the coverage area.
This is the slowest and highest quality
reconstruction function. It is derived from the hyperbolic filters in
Wolberg's "Digital Image Warping", and is formally defined as the
hyperbolic-filter sampling the ideal hyperbolic-filter interpolated
image (the filter is designed to be idempotent for 1:1 pixel mapping).
Deprecated: this interpolation filter is deprecated, as in reality
it has a lower quality than the GDK_INTERP_BILINEAR filter
(Since: 2.38)
Nearest neighbor sampling; this is the fastest and lowest quality mode. Quality is normally unacceptable when scaling down, but may be OK when scaling up.
This is an accurate simulation of the PostScript image operator without any interpolation enabled. Each pixel is rendered as a tiny parallelogram of solid color, the edges of which are implemented with antialiasing. It resembles nearest neighbor for enlargement, and bilinear for reduction.
Interpolation modes for scaling functions.
The
GDK_INTERP_NEARESTmode is the fastest scaling method, but has horrible quality when scaling down;GDK_INTERP_BILINEARis the best choice if you aren't sure what to choose, it has a good speed/quality balance.Note: Cubic filtering is missing from the list; hyperbolic interpolation is just as fast and results in higher quality.