.TH IM_PROJECT 3 "10 April 2006"
.SH NAME
im_project \- find horizontal and vertical projections
.SH SYNOPSIS
#include <vips/vips.h>

int im_project(IMAGE *in, IMAGE *hout, IMAGE *vout)

.SH DESCRIPTION
.B im_project(3) 
finds the horizontal and vertical projections of an image, that is, the sum of
each row and the sum of each column.

The 
.B hout
result image is 1 x in->Ysize pixels, where each pixel is the sum of all the
pixels in that row of the input image.
The 
.B vout
result image is in->Xsize x 1 pixels, where each pixel is the sum of all the
pixels in that column of the input image.

The output images are of the largest appropriate type for the input image: so 
unsigned integer images produce UINT output, and so on. The output images have
the same number of bands as the input.

The operation does not work for complex images, or for coded images.

.SH RETURNED VALUE
The function returns 0 on success and -1 on error.
.SH SEE ALSO
im_histplot(3), im_histnorm(3), im_extract(3).
.SH COPYRIGHT
Imperial College, 2006