int im_embed( in, out, type, x, y, w, h )
IMAGE *in, *out;
int type;
int x, y, w, h;
0 - black pels (only flag supported in this version)
1 - mirror pels from image
2 - tile pels from image
3 - extend pels from image to edge
4 - etc.
Works for any size image, any number of bands, any type. Works for LABPACK coded images too!
This is a special PIO functions, and effectively adds no execution time penalty if used with other PIO operations. It is used by im_fastcor(), im_spcor(), im_conv() etc. to add black borders to their output images.