lvslope - Compute slope and aspect images from elevation data.
LIBRARY CALL
int lvslope(
xvimage *img1,
int slope_flag,
int slope_option,
int aspect_flag,
int aspect_option,
float no_aspect,
xvimage **img2,
xvimage **img3)
INPUT
img1 - A pointer to the input viff structure.
slope_flag - When set to 1, this flag causes the slope
image to be created. 0 means no slope
image is created.
slope_option - Determines the form of the slope output:
0=degrees, 1=radians, 2=percent.
aspect_flag - When set to 1, this flag causes the aspect
image to be created. 0 means no aspect
image is created.
aspect_option - Determines the form of the aspect output:
0=degrees, 1=radians, 2=quadrants.
no_aspect - Value given for the aspect of a flat
surface. The aspect gives the direction
the slope is facing. When there is no
slope the, aspect is given this value to
denote that it is undefined.
OUTPUT
img2 - A double pointer to the slope viff structure.
Only used if slope_flag is set.
img3 - A double pointer to the aspect viff structure.
Only used if aspect flag is set.
RETURN VALUE
TRUE (1) on success, FALSE (0) on failure
DESCRIPTION
Library Routine for vslope
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
lvslope works on input images with data types byte
(VFF_TYP_1_BYTE), short (VFF_TYP_2_BYTE), int
(VFF_TYP_4_BYTE), and float (VFF_TYP_FLOAT), but the
type of the output image will always be float regardless
of the input type. Maps on the input image will be
transfered directly to the output image, but forced maps
(VFF_MAP_FORCE) are not accepted. Explicit location data
is not accepted. The input image is restricted to one
image per file.
MODIFICATION
none
FILES
$RETRO/objects/library/vipl/src/lvslope.c
SEE ALSO
vipl(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.