| .TH IM_RIGHTSHIFT_SIZE 3 "12 August 2006" |
| .SH NAME |
| im_rightshift_size \- Decrease size by a power-of-two factor |
| .SH SYNOPSIS |
| .nf |
| .B #include <vips/vips.h> |
| .sp |
| .BI "int im_rightshift_size( IMAGE " "*in" ", IMAGE " "*out" ", int " "xshift" ", int " "yshift" ", int " "band_fmt" " ); |
| .fi |
| .SH DESCRIPTION |
| .B im_rightshift_size(3) |
| decreases the size of an integer type image by a power-of-two factor, very quickly, by summing the values of |
| adjacent pixels. The sum is shifted to produce output of the specified band format. |
| .IR xshift " and "yshift |
| are positive and give the base-two logarithms of the scale factors. |
| .PP |
| If the input image is a signed type, then |
| .I band_fmt |
| must be one of IM_BANDFMT_CHAR, IM_BANDFMT_SHORT or IM_BANDFMT_INT. If it is an unsigned type, then |
| .I band_fmt |
| must be one of IM_BANDFMT_UCHAR, IM_BANDFMT_USHORT or IM_BANDFMT_UINT. |
| .SH RETURN VALUE |
| The functions returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_affine(3) |
| .SH COPYRIGHT |
| .br |
| Copyright 2006, Tom Vajzovic. |
| .SH AUTHOR |
| Tom Vajzovic |
