im_region_create3

Usage

Overview

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.