| .TH IM_EXTRACT 3 "11 April 1990" |
| .SH NAME |
| im_extract_areabands, im_extract_bands, im_extract_area \- extract a portion of an image |
| .SH SYNOPSIS |
| .B #include <vips/vips.h> |
| |
| int im_extract_areabands( IMAGE *in, IMAGE *out, |
| .br |
| int left, int top, int width, int height, int band, int nbands ) |
| |
| int im_extract_area( IMAGE *in, IMAGE *out, |
| .br |
| int left, int top, int width, int height ) |
| |
| int im_extract_bands( IMAGE *in, IMAGE *out, |
| .br |
| int chsel, int nbands ) |
| |
| .SH DESCRIPTION |
| .B im_extract_areabands(3) |
| extracts the rectangular portion of the image defined by |
| .B left, |
| .B top, |
| .B width, |
| and |
| .B height of image |
| .B in |
| and writes the result to image |
| .B out. |
| The area must lie entirely within in the image. Selects the set of |
| .B nbands |
| bands |
| starting at band number |
| .B band |
| (numbering bands from zero). |
| |
| Works for any size image, any number of bands, any type. Works for LABPACK |
| coded images too! But disallows band extraction in this case. |
| |
| .B im_extract_area(3) |
| is a convenience function which extracts an area from an |
| image, leaving the bands the same. |
| |
| .B im_extract_bands(3) |
| takes |
| .B nbands |
| out of an image, starting from band |
| .B band. |
| So, for example, nbands == 2, bands == 1 will form a two band image from an RGB |
| image, where the two bands are the G and the B bands. |
| |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_insert(3), im_lrjoin(3), im_lrmerge(3), im_stats(3), |
| im_region_region(3). |
| .SH COPYRIGHT |
| J. Cupitt, |
| .SH AUTHOR |
| J. Cupitt \- 11/04/1990 |
