SUBARR

Name

subarr

Purpose (one Line Only)

Extract a sub-array from an image with bound checking

Description

Return a portion of an image as a sub-array. The requested location for
the sub-array is checked against the real boundary of the original image
and portions of the sub-array that fall off the image are padded out
with either zeros or a noisy background filler.
An error is generated only when there is no overlap between the requested
sub-array and the image.

Calling Sequence

subarr,image,i0,i1,j0,j1,sub,error

Inputs

image - The input image
i0 - Bottom of the sub-array location
j0 - Left boundary of the sub-array location
i1 - Top of the sub-array location
j1 - Right boundary of the sub-array location

Optional Input Parameters

Keyword Input Parameters

FILL - value to use to fill non-overlap regions between sub and image
(default=0)
NOISE - noise value for FILL (default=0), this will not always be useful
for non-floating point data types.
SEED - seed value for random number generator. This is used only when
NOISE is non-zero. It is only needed if you are trying to
create the same set of random values for testing. Under normal
circumstances there is no need to ever specify this value.

Outputs

sub - sub-array from image, if an error occurs this will be returned as
a scalar zero.
error - Flag, set if an error occurred. The only time this happens is if
the requested area has no overlap with the image.

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

Written by Marc W. Buie, Southwest Research Insitute, 2015/06/30
2016/12/28, MWB, added byte input option for FILL