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NAME

       lqr_rwindow_read - read the content of a LqrReadingWindow object

SYNOPSIS

       #include <lqr.h>

       gfloat lqr_rwindow_read(LqrReadingWindow* rwindow, gint x, gint y,
                               gint channel);

DESCRIPTION

       The function lqr_rwindow_read returns the content of the reading window
       rwindow at point x, y and at channel channel.

       The coordinates x and y are relative to the rwindow centre, and they
       both can range from -radius to radius (extremes included), where radius
       can be obtained with the function lqr_rwindow_get_radius(3).

       The function returns 0 when the coordinates are out of range, either
       because they are beyond the rwindow radius or because they are outside
       the image boundary.

       The channel parameter specifies which channel to read out; depending on
       the rwindow reader type, the range and meaning of this parameter
       changes: for the cases LQR_ER_BRIGHTNESS and LQR_ER_LUMA it must be 0,
       because the readout consists of a single channel, for LQR_ER_RGBA it
       must be between 0 and 3 (and then the readout will contain the RGBA
       information), while for LQR_ER_CUSTOM it must be one of the original
       image channels.

SEE ALSO

       lqr_carver_set_energy_function(3), lqr_rwindow_get_read_t(3),
       lqr_rwindow_get_radius(3), lqr_rwindow_get_channels(3)

COPYRIGHT

       Copyright © 2007-2009 Carlo Baldassi