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/*
=head1 NAME
combine.im - combining channels into an image
=head1 SYNOPSIS
out = i_combine(imgs, channels, count);
=head1 DESCRIPTION
Combines channels from the input images into an output image.
=over
=cut
*/
#include "imager.h"
i_img *
i_combine(i_img **imgs, const int *channels, int in_count) {
i_img *out = NULL;
int maxbits = 0;
i_img *maximg = NULL;
int i;
i_img_dim width, height;
i_img_dim x, y;
i_clear_error();
if (in_count <= 0) {
i_push_error(0, "At least one image must be supplied");
return NULL;
}
if (in_count > MAXCHANNELS) {
i_push_errorf(0, "Maximum of %d channels, you supplied %d",
MAXCHANNELS, in_count);
return NULL;
}
width = imgs[0]->xsize;
height = imgs[0]->ysize;
for (i = 0; i < in_count; ++i) {
if (imgs[i]->bits > maxbits) {
maximg = imgs[i];
maxbits = maximg->bits;
}
if (imgs[i]->xsize < width)
width = imgs[i]->xsize;
if (imgs[i]->ysize < height)
height = imgs[i]->ysize;
if (channels[i] < 0) {
i_push_error(0, "Channel numbers must be zero or positive");
return NULL;
}
if (channels[i] >= imgs[i]->channels) {
i_push_errorf(0, "Channel %d for image %d is too high (%d channels)",
channels[i], i, imgs[i]->channels);
return NULL;
}
}
out = i_sametype_chans(maximg, width, height, in_count);
if (!out)
return NULL;
#code maxbits <= i_8_bits
IM_SAMPLE_T *in_row = mymalloc(sizeof(IM_SAMPLE_T) * width);
IM_COLOR *out_row = mymalloc(sizeof(IM_COLOR) * width);
for (y = 0; y < height; ++y) {
for (i = 0; i < in_count; ++i) {
IM_GSAMP(imgs[i], 0, width, y, in_row, channels + i, 1);
for (x = 0; x < width; ++x)
out_row[x].channel[i] = in_row[x];
}
IM_PLIN(out, 0, width, y, out_row);
}
myfree(out_row);
myfree(in_row);
#/code
return out;
}
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