window

Name

Syntax

 #include <xite/ideal.h>

 int window(IBAND band, int size,
    window_type win_type);

Description

BARTLETT

Circularly symmetric Bartlett (triangular) window

HAMMING

Circularly symmetric Hamming window

HANNING

Circularly symmetric Hanning (von Hann) window

RECTANGLE

Circularly symmetric rectangular (box, boxcar) window function

TRIANGLE

Circularly symmetric triangular window function

The window is returned with its center in the center of band. This means that the actual center will be located between two pixels in the horizontal direction when the horizontal band size is even. When the vertical band size is even, the center will be located between two pixels in the vertical direction. When both horizontal and vertical band size is even, the window center will be located between four pixels. With both horizontal and vertical band size odd, the window center will be located exactly inside the center pixel of the band.

To be applied as a multiplicative window to an image-domain filter, make sure that also the filter-function is centered around the band center, or if the filter-function is centered around a band corner, the window must be shifted correspondingly before it can be applied. With center on a band corner, the resulting filter may be zero phase (if the filter function itself obeys the necessary symmetry relations).

Return value

 0 : Ok
 1 : Unknown window type

See also

Author

Id