Method
VipsImagereduceh
Declaration [src]
int
vips_reduceh (
VipsImage* in,
VipsImage** out,
double hshrink,
...
)
Description [src]
Optional arguments:
kernel:VipsKernelto use to interpolate (default: lanczos3)gap: reducing gap to use (default: 0.0)
Reduce in horizontally by a float factor. The pixels in out are
interpolated with a 1D mask generated by kernel.
Set gap to speed up reducing by having vips_shrinkh() to shrink
with a box filter first. The bigger gap, the closer the result
to the fair resampling. The smaller gap, the faster resizing.
The default value is 0.0 (no optimization).
This is a very low-level operation: see vips_resize() for a more
convenient way to resize images.
This operation does not change xres or yres. The image resolution needs to be updated by the application.
See also: vips_shrink(), vips_resize(), vips_affine().
This method is not directly available to language bindings.
Parameters
out-
Type:
VipsImageOutput 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. hshrink-
Type:
doubleHorizontal reduce.
...-
Type:
NULL-terminated list of optional named arguments.