| .TH IM_RECOMB 3 "11 April 1990" |
| .SH NAME |
| im_recomb \- matrix recombination of image |
| .SH SYNOPSIS |
| #include <vips/vips.h> |
| |
| int im_recomb(imagein, imageout, mat) |
| .br |
| IMAGE *imagein, *imageout; |
| .br |
| DOUBLEMASK *mat; |
| |
| .SH DESCRIPTION |
| im_recomb() recombines the elements of an m band image to form an n band image |
| using mat, an m by n matrix of floating point numbers. |
| |
| It calculates |
| |
| A = B x C |
| |
| where A is an n band output image, C is an m band input image and B |
| is an m by n matrix of floats. Can be used with a 3 by 3 matrix to perform |
| simple colour space transforms; 7 by 30 matrix to shrink 3rd order |
| development of 3 filter system to XYZ etc. |
| |
| The output type is float unless the input type is double, in which case the |
| output type is double. It does not work for complex image types. All |
| intermediates are calculated as double. Note that the width of the matrix |
| should be equal to the number of bands in the input image. |
| |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_read_dmask(3), im_matinv(3), im_lintra(3) |
| .SH COPYRIGHT |
| National Gallery and Birkbeck College, 1990 - 1996 |
