| .TH SUBTRACTION 3 "24 April 1991" |
| .SH NAME |
| im_subtract \- subtracts two images |
| .SH SYNOPSIS |
| #include <vips/vips.h> |
| |
| int im_subtract(in1, in2, out) |
| .br |
| IMAGE *in1, *in2, *out; |
| .SH DESCRIPTION |
| |
| This functions calculates in1 - in2 and writes the result in the image |
| descriptor out. Input images in1 and in2 should have the same channels and |
| the same sizes; however they can be of different types. Only the history of |
| the image descriptor pointed by in1 is copied to out. |
| |
| The type of the output is given by the table: |
| |
| in1 - uchar char ushort short uint int |
| -------|----------------------------------------- |
| in2 | |
| uchar | short short short short int int |
| char | short short short short int int |
| ushort | short short short short int int |
| short | short short short short int int |
| uint | int int int int int int |
| int | int int int int int int |
| |
| The result of this operation cannot be unsigned. For float types, the refult |
| is float unless one of the inputs is double, in which case the result is |
| double. For complex types the result is FMTCOMPLEX, unless one of the inputs |
| is FMTDPCOMPLEX, in which case the output is FMTDPCOMPLEX. |
| |
| .SH BUGS |
| None of the functions checks the result for over/underflow. |
| .SH RETURN VALUE |
| All functions return 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_add(3), im_lintra(3), im_multiply(3). |
| .SH COPYRIGHT |
| National Gallery, 1995 |
