PREDICATES

Section: C Library Functions (3)
Updated: 11 April 1990
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NAME

im_region_create, im_region_free - region creation and destruction  

SYNOPSIS

#include <vips/vips.h>

REGION *im_region_create( im )
IMAGE *im;

int im_region_free( reg )
REGION *reg;  

DESCRIPTION

These functions create and destroy regions on images. Regions are used for PIO, see accompanying documentation. Regions have type


    typedef struct {
        Rect valid  /* Area of im represented */
        IMAGE *im;  /* im we are defined on */


        ... more fields, all private and used for
        ... housekeeping
    } REGION;

im_region_create(3) returns a pointer to a new region, or NULL on error. Regions are made blank, with no input or output possible. See im_prepare(3), im_generate(3), im_start_one(3) and IM_REGION_ADDR(3).

im_region_free(3) frees a region and any resources associated with that region. When an image is closed, all regions which have been created on that image are automatically freed.  

RETURN VALUE

All int-valued functions return zero on success and non-zero on error.  

COPYRIGHT

National Gallery, 1993  

AUTHOR

J. Cupitt - 23/7/93